CN215904328U

CN215904328U - Charging system and electric automobile

Info

Publication number: CN215904328U
Application number: CN202120172706.1U
Authority: CN
Inventors: 程洋; 章雪亮
Original assignee: Huawei Digital Power Technologies Co Ltd
Current assignee: Huawei Digital Power Technologies Co Ltd
Priority date: 2021-01-21
Filing date: 2021-01-21
Publication date: 2022-02-25
Anticipated expiration: 2031-01-21

Abstract

The application provides a charging system and electric automobile, this charging system mainly includes MCU and motor, N bridge arm through multiplexing MCU and N motor winding in the motor can constitute voltage conversion circuit, MCU can be when mains voltage is less than power battery's minimum charging voltage, carry out the conversion of stepping up through above-mentioned voltage conversion circuit to mains voltage to power battery is exported as first output voltage after will stepping up the conversion, this first output voltage is not less than minimum charging voltage. According to the charging system, the space and the cost occupied by the charging system can be reduced while the charging system is utilized to perform voltage reduction conversion on the power supply voltage.

Description

Charging system and electric automobile

Technical Field

The application relates to the technical field of new energy vehicles, in particular to a charging system and an electric vehicle.

Background

With the development of new energy technology, electric vehicles are receiving increasingly wide attention. Be provided with power battery among the electric automobile, power battery can receive and the electric energy that the storage was filled the electric pile and is provided to at electric automobile driving in-process, power battery release the electric energy of storage, thereby the drive electric automobile traveles.

In order to increase the charging speed of electric vehicles, more and more electric vehicles use 800V high-voltage power batteries, and the charging voltage required by the high-voltage power batteries is often not lower than 800V. However, most direct current rapid charging piles in the market have output voltage of more than 500V, and the charging piles can not directly charge the high-voltage power battery of 800V, so that the electric automobile equipped with the high-voltage power battery faces the problem of difficult charging, and the improvement of user experience is not facilitated.

Therefore, the charging scheme of the electric vehicle is still under further study.

SUMMERY OF THE UTILITY MODEL

In view of this, the present application provides a charging system and an electric vehicle, which is beneficial to enable the electric vehicle to still support the power voltage to charge the power battery when the power voltage is less than the minimum charging voltage of the power battery.

In a first aspect, the present application provides a charging system, which mainly includes a motor controller MCU and a motor, where the MCU includes N bridge arms, the motor includes N motor windings, and the N bridge arms in the MCU and the N motor windings in the electrodes are respectively connected in a one-to-one correspondence, where N is an integer greater than or equal to 1. The high-potential ends of the N bridge arms, a first power supply end and a first battery end of the charging system, the first power supply end can be connected with the positive electrode of the direct-current power supply, the first battery end can be connected with the positive electrode of the power battery, the direct-current power supply can output power supply voltage, and the power battery can receive the first output voltage of the charging system. In the MCU, the low potential ends of the N bridge arms are connected with a second battery end of the charging system, and the second battery end can be connected with the negative electrode of the power battery. In the motor, one end of each of the N motor windings is connected with the middle point of the corresponding bridge arm, the other end of each of the N motor windings is connected with a second power supply end of the charging system, and the second power supply end can be connected with the negative electrode of the direct-current power supply. The N bridge arms and the N motor windings can form a voltage conversion circuit, the MCU can perform boost conversion on the power supply voltage through the voltage conversion circuit when the power supply voltage is smaller than the minimum charging voltage of the power battery, and output the power supply voltage subjected to boost conversion to the power battery as a first output voltage which is not smaller than the minimum charging voltage.

To sum up, this application has realized a charging system through multiplexing MCU and motor. When the power supply voltage is less than the minimum charging voltage of the power battery, the charging system can perform boost conversion on the power supply voltage so as to obtain a first output voltage which is not less than the minimum charging voltage, and the first output voltage can be adapted to the power battery so as to charge the power battery. Simultaneously, this application has multiplexed common MCU and motor among the electric automobile, still is favorable to reducing occupied space and the cost of charging system.

Illustratively, the first aspect of the present application provides the following examples for illustration:

example 1

Any one of the N bridge arms is a first bridge arm, the first bridge arm comprises a first switch tube and a second switch tube, a first electrode of the first switch tube is respectively connected with a first battery end and a first power supply end, a second electrode of the first switch tube is connected with a first electrode of the second switch tube, and a middle point of the first bridge arm is located between the first switch tube and the second switch tube. When the power supply voltage is lower than the minimum charging voltage of the power battery, the MCU can conduct the first switch tube so as to charge the first motor winding correspondingly connected with the first bridge arm. The MCU turns off the first switch tube to discharge the first motor winding.

Specifically, when the MCU is turned on the first switching tube, the current is output from the positive electrode of the dc power supply, and then reaches the first motor winding through the first switching tube, so that the first motor winding is charged. When the MCU turns off the first switching tube, the first motor winding starts to discharge. The current is output from one end of the first motor winding close to the second power supply end, and flows back to one end of the first motor winding close to the second switching tube after being transmitted by the direct-current power supply, the power battery and the diode in the second switching tube. In the process, the direct current power supply and the first motor winding are in series discharge, and the first output voltage is the sum of the power supply voltage and the voltage of the first motor winding. Obviously, the first output voltage is greater than the supply voltage, and therefore a boost conversion can be achieved.

It is understood that the supply voltage provided by the dc power supply may also be within the charging voltage range of the power battery, i.e. the supply voltage is adapted to the power battery. In order to be compatible with the scenario, the charging system in this application may further include a first switch, a first terminal of the first switch is connected to the second battery terminal, and a second terminal of the first switch is connected to the second power supply terminal. The MCU can also conduct the first switch when the power supply voltage is within the charging voltage range of the power battery; and turning off the first switch when the power supply voltage is outside the charging voltage range of the power battery.

Specifically, when the first switch is turned on, the power battery may be directly connected to the dc power source, so that the power battery may directly receive the power voltage provided by the dc power source to complete charging. Therefore, when the power supply voltage is within the charging voltage range of the power battery, the first switch can be conducted. When the first switch is turned off, the MCU may convert the power supply voltage and supply the converted power supply voltage as a first output voltage to the power battery. Therefore, the first switch may be turned off when the power supply voltage is outside the charging voltage range of the power battery.

As previously mentioned, the first motor winding needs to store electrical energy when performing the boost conversion. However, in some machines the inductance of the motor windings may not be sufficient to support the boost conversion. In view of this, the charging system of the present application further includes a first inductor, one end of the first inductor is connected to the other ends of the N motor windings, and the other end of the first inductor is connected to the second power supply terminal. When the first motor winding is charged, the first inductor is charged synchronously. When the first motor winding discharges, the first inductor discharges synchronously. At this time, the first output voltage is the sum of the power supply voltage, the voltage of the first motor winding, and the voltage of the first inductor. Therefore, adding the first inductance is advantageous for further increasing the first output voltage.

Example two

It is anticipated that in some scenarios, the power supply voltage may also be greater than the maximum charging voltage of the power battery. In view of this, in the present application, when the power supply voltage is greater than the maximum charging voltage of the power battery, the MCU may further perform voltage-down conversion on the power supply voltage through the voltage conversion circuit, and output the power supply voltage after voltage-down conversion to the power battery as a first output voltage, where the first output voltage is not greater than the maximum charging voltage. In this case, the electric vehicle can receive a large power supply voltage, and the power supply voltage is converted to charge the power battery, which is advantageous for improving the charging convenience.

Illustratively, any one of N bridge arms of the MCU is a first bridge arm, and the first bridge arm includes a first switching tube and a second switching tube, wherein a first electrode of the first switching tube is connected to the first battery terminal and the first power terminal, a second electrode of the first switching tube is connected to a first electrode of the second switching tube, and a midpoint of the first bridge arm is located between the first switching tube and the second switching tube. The charging system can further comprise a first switch and a second switch, wherein the first end of the first switch is connected with the second battery end, the second end of the first switch is connected with the second power supply end, the first end of the second switch is connected with the first battery end, the second end of the second switch is connected with the other ends of the N motor windings, and the third end of the second switch is connected with the first power supply end.

Based on the charging system, when the power supply voltage is greater than the maximum charging voltage of the power battery, the MCU can conduct the first switch and conduct the first end and the second end of the second switch. The MCU is used for conducting the first switching tube so as to charge the first motor winding correspondingly connected with the first bridge arm. The MCU turns off the first switch tube to discharge the first motor winding.

Specifically, the MCU can charge the first motor winding after turning on the first switching tube, and the first output voltage is a voltage difference obtained by subtracting a voltage of the first motor winding from a power voltage. The MCU can discharge the first motor winding after the first switching tube is switched off, and at the moment, the first output voltage is the voltage of the first motor winding. Therefore, the first output voltage is always smaller than the power supply voltage, so that the charging system can perform voltage reduction conversion on the power supply voltage.

It should be noted that the charging system provided in the second example can also perform the step-up conversion on the power supply voltage. For example, the charging system may further include a third switch having a first terminal connected to the other end of the N motor windings and a second terminal connected to the second power terminal. When the power supply voltage is less than the minimum charging voltage of the power battery, the MCU may turn on the first terminal and the third terminal of the second switch, turn on the third switch, and turn off the first switch. The MCU is used for conducting the first switch tube so as to charge the first motor winding corresponding to the first bridge arm. And turning off the first switching tube to discharge the first motor winding.

Specifically, the MCU can charge the first motor winding after turning on the first switching tube. The MCU can discharge the first motor winding after the first switching tube is switched off, and the first output voltage is the sum of the voltage of the first motor winding and the power voltage. It follows that the first output voltage is greater than the supply voltage, and therefore the charging system can up-convert the supply voltage.

In addition, the charging system provided in the second example can also perform buck-boost (buck-boost) conversion on the power supply voltage. For example, the charging system may further include a third switch having a first terminal connected to the other end of the N motor windings and a second terminal connected to the second power terminal. The MCU may turn on the first and second terminals of the second switch and turn on the third switch. The MCU is used for conducting the first switch tube so as to charge the first motor winding correspondingly connected with the first bridge arm. The MCU turns off the first switch tube to discharge the first motor winding.

Specifically, the MCU can charge the first motor winding after turning on the first switching tube. The MCU can discharge the first motor winding after the first switching tube is switched off, and at the moment, the first output voltage is the voltage of the first motor winding. The voltage of the first motor winding is dependent upon the length of time that the first motor winding is charged, and therefore, by adjusting the length of time that the first motor winding is charged, the magnitude of the first output voltage, which may be greater than the supply voltage (step-up conversion) or less than the supply voltage (step-down conversion), may be adjusted.

It can be understood that the charging system provided in example two of the present application can also be compatible with a scenario in which the power supply voltage matches the power battery. For example, the MCU may further turn on the first terminal and the third terminal of the second switch and turn on the first switch when the power voltage is within the charging voltage range of the power battery. In this case, the power battery is directly connected to the dc power source and can directly receive the power voltage to complete the charging.

In a second aspect, the present application further provides a charging system, which mainly includes a motor controller MCU and a motor. The MCU comprises N bridge arms, the motor comprises N motor windings, the N bridge arms and the N motor windings are respectively connected in a one-to-one correspondence mode, and N is an integer greater than or equal to 1. The high-potential ends of the N bridge arms are connected with a first power supply end and a first battery end of the charging system, the first power supply end can be connected with the anode of a direct-current load, the first battery end can be connected with the anode of a power battery, the direct-current load can receive second output voltage of the charging system, and the power battery can output battery voltage to the charging system. And the low potential ends of the N bridge arms are connected with a second battery end of the charging system, and the second battery end can be connected with the negative electrode of the power battery. One end of each of the N motor windings is connected with the middle point of the corresponding bridge arm, the other end of each of the N motor windings is connected with a second power supply end of the charging system, and the second power supply end is used for being connected with the negative electrode of the direct-current load. The voltage conversion circuit is formed by the N bridge arms and the N motor windings, the MCU can perform voltage reduction conversion on the battery voltage through the voltage conversion circuit when the battery voltage is larger than the maximum working voltage of the direct-current load, the battery voltage subjected to voltage reduction conversion is output to the direct-current load as a second output voltage, and the second output voltage is not larger than the maximum working voltage.

To sum up, this application has realized a charging system through multiplexing MCU and motor. When the battery voltage is greater than the maximum working voltage of the direct-current load, the charging system can perform voltage reduction conversion on the battery voltage, so that a second output voltage which is not greater than the maximum working voltage is obtained, the second output voltage can be adaptive to the direct-current load, and power can be supplied to the direct-current load. Simultaneously, this application has multiplexed common MCU and motor among the electric automobile, still is favorable to reducing occupied space and the cost of charging system.

Illustratively, the second aspect of the present application provides the following examples for illustration:

example 1

Illustratively, any one of the N bridge arms is a first bridge arm, and the first bridge arm includes a first switching tube and a second switching tube, wherein a first electrode of the first switching tube is connected to the first battery terminal and the first power terminal, a second electrode of the first switching tube is connected to a first electrode of the second switching tube, and a midpoint of the first bridge arm is located between the first switching tube and the second switching tube. When the battery voltage is greater than the maximum working voltage of the direct-current load, the MCU can conduct the second switching tube so as to charge the first motor winding correspondingly connected with the first bridge arm. The MCU turns off the second switching tube to discharge the first motor winding.

Specifically, after the second switching tube is conducted by the MCU, the first motor winding can be charged. At this time, the first output voltage is a voltage difference obtained by subtracting the voltage of the first motor winding from the power supply voltage. After the second switching tube is turned off by the MCU, the first motor winding can be discharged, and at the moment, the first output voltage is the voltage of the first motor winding. It can be seen that the first output voltage is always smaller than the battery voltage, and therefore, the charging system provided in the first example of the present application can implement the step-down conversion of the battery voltage.

It will be appreciated that the battery voltage of the power battery may also be adapted to the dc load. In order to be compatible with the scenario, the charging system may further include a first switch, a first terminal of the first switch is connected to the second battery terminal, and a second terminal of the first switch is connected to the second power supply terminal. The MCU can also conduct the first switch when the battery voltage is within the working voltage range of the direct current load; and turning off the first switch when the battery voltage is outside the operating voltage range of the direct current load.

When the first switch is turned on, the power battery can be directly connected with the direct current load to directly supply power to the direct current load. When the first switch is turned off, the MCU may convert the battery voltage and provide the converted battery voltage as a second output voltage to the dc load.

As previously mentioned, the first motor winding needs to store electrical energy when performing the step-down conversion. However, in some machines the inductance of the motor windings may not be sufficient to support buck conversion. In view of this, the charging system of the present application further includes a first inductor, one end of the first inductor is connected to the other ends of the N motor windings, and the other end of the first inductor is connected to the second power supply terminal. When the first motor winding is charged, the first inductor is charged synchronously. When the first motor winding discharges, the first inductor discharges synchronously. At this time, the first output voltage is a voltage difference obtained by subtracting the voltage of the first motor winding and the voltage of the first inductor from the power supply voltage. Therefore, increasing the first inductance is advantageous for further reducing the second output voltage.

Example two

It is anticipated that in some scenarios, the battery voltage may also be less than the minimum operating voltage of the dc load. In view of this, in the present application, the MCU may further perform voltage boost conversion on the battery voltage through the voltage conversion circuit when the battery voltage is less than the minimum operating voltage of the power battery, and output the battery voltage after the voltage boost conversion to the dc load as a second output voltage, where the second output voltage is not less than the minimum operating voltage of the power battery.

Illustratively, any one of N bridge arms in the MCU is a first bridge arm, and the first bridge arm includes a first switching tube and a second switching tube, wherein a first electrode of the first switching tube is connected to the first battery terminal and the first power terminal, a second electrode of the first switching tube is connected to a first electrode of the second switching tube, and a midpoint of the first bridge arm is located between the first switching tube and the second switching tube. The charging system can further comprise a first switch and a second switch, wherein the first end of the first switch is connected with the second battery end, the second end of the first switch is connected with the second power supply end, the first end of the second switch is connected with the first battery end, the second end of the second switch is connected with the other ends of the N motor windings, and the third end of the second switch is connected with the first power supply end.

Based on the charging system, when the battery voltage is less than the minimum working voltage of the direct current load, the MCU can conduct the first switch and conduct the first end and the second end of the second switch; the second switching tube is conducted so as to charge a first motor winding correspondingly connected with the first bridge arm; and turning off the second switching tube to discharge the first motor winding.

Specifically, the MCU can charge the first motor winding after the second switching tube is conducted. The MCU can discharge the first motor winding after the second switching tube is switched off, and the second output voltage is the sum of the voltage of the battery and the voltage of the first motor winding. As can be seen, the second output voltage is greater than the battery voltage, and thus the charging system can up-convert the battery voltage.

It should be noted that the charging system provided in the second example can also perform voltage down conversion on the battery voltage. For example, the charging system may further include a third switch, a first terminal of which is connected to the other terminal of the N motor windings, and a second terminal of which is connected to the second power supply terminal. When the battery voltage is greater than the maximum working voltage of the direct-current load, the MCU can conduct the first end and the third end of the second switch, conduct the third switch and turn off the first switch. And the MCU is used for conducting the second switching tube so as to charge the first motor winding corresponding to the first bridge arm. The MCU turns off the second switching tube to discharge the first motor winding.

Specifically, the MCU can charge the first motor winding after turning on the second switching tube, and the second output voltage is a voltage difference obtained by subtracting the voltage of the first motor winding from the battery voltage. The MCU can discharge the first motor winding after the second switching tube is switched off, and the second output voltage is the voltage of the first motor winding at the moment. It follows that the second output voltage is always less than the battery voltage, and therefore the charging system can down-convert the battery voltage.

In addition, the charging system provided in the second example can also perform buck-boost (buck-boost) conversion on the battery voltage. Illustratively, the charging system may further include a third switch, a first terminal of the third switch being connected to the other terminal of the N motor windings, and a second terminal of the third switch being connected to the second power supply terminal. The MCU may turn on the first and second terminals of the second switch and turn on the third switch. And the MCU is used for conducting the second switching tube so as to charge the first motor winding correspondingly connected with the first bridge arm. The MCU turns off the second switching tube to discharge the first motor winding.

Specifically, the MCU can charge the first motor winding after the second switching tube is conducted. The MCU can discharge the first motor winding after the second switching tube is switched off, and the second output voltage is the voltage of the first motor winding at the moment. The voltage of the first motor winding is dependent upon the length of time that the first motor winding is charged, and therefore, by adjusting the length of time that the first motor winding is charged, the magnitude of the second output voltage, which may be greater than the battery voltage (step-up conversion) or less than the battery voltage (step-down conversion), may be adjusted.

It can be understood that the charging system provided in example two of the present application is also compatible with a scenario where the battery voltage matches the dc load. Illustratively, the MCU may also turn on the first terminal and the third terminal of the second switch, and turn on the first switch when the battery voltage is within the operating voltage range of the dc load. In this case, the power battery is directly connected with the direct current load, and can directly supply power to the direct current load.

In a third aspect, the present application provides a charging system, which mainly includes a motor controller MCU and a motor. The MCU comprises N bridge arms, the motor comprises N motor windings, the N bridge arms and the N motor windings are respectively connected in a one-to-one correspondence mode, and N is an integer greater than or equal to 1. The high-potential ends of the N bridge arms are connected with a first battery end of the charging system, the first battery end can be connected with the anode of the power battery, and the power battery can receive a first output voltage of the charging system. The low potential ends of the N bridge arms are connected with a second battery end and a second power supply end of the charging system, the second battery end can be connected with the negative electrode of the power battery, the second power supply end can be connected with the negative electrode of the direct-current power supply, and the direct-current power supply can output power supply voltage. One end of each of the N motor windings is connected with the middle point of the corresponding bridge arm, the other end of each of the N motor windings is connected with a first power supply end of the charging system, and the first power supply end can be connected with the positive electrode of the direct-current power supply. The voltage conversion circuit is formed by the N bridge arms and the N motor windings, the MCU can perform boost conversion on the power supply voltage through the voltage conversion circuit when the power supply voltage is smaller than the minimum charging voltage of the power battery, and outputs the power supply voltage subjected to boost conversion to the power battery as a first output voltage which is not smaller than the minimum charging voltage; when the power supply voltage is greater than the maximum charging voltage of the power battery, the power supply voltage is subjected to voltage reduction conversion through the voltage conversion circuit, the power supply voltage subjected to voltage reduction conversion is output to the power battery as a first output voltage, and the first output voltage is not greater than the maximum charging voltage.

Illustratively, any one of the N bridge arms is a first bridge arm, and the first bridge arm includes a first switching tube and a second switching tube, where a first electrode of the first switching tube is connected to the first battery terminal and the first power supply terminal, a second electrode of the first switching tube is connected to a first electrode of the second switching tube, and a middle point of the first bridge arm is located between the first switching tube and the second switching tube. The charging system further comprises a sixth switch and a fifth switch, wherein the first end of the fifth switch is connected with the second battery end, the second end of the fifth switch is connected with the low-potential ends of the N bridge arms, the third end of the fifth switch is connected with the other ends of the N motor windings, the first end of the sixth switch is connected with the first battery end, and the second end of the sixth switch is connected with the first power supply end.

When the power supply voltage is greater than the maximum charging voltage of the power battery, the MCU can conduct the sixth switch and conduct the first end and the third end of the fifth switch. And the MCU is used for conducting the second switching tube so as to charge the first motor winding correspondingly connected with the first bridge arm. And turning off the second switching tube to discharge the first motor winding.

Specifically, the MCU can charge the first motor winding after turning on the second switching tube, and the first output voltage is a voltage difference obtained by subtracting a voltage of the first motor winding from a power supply voltage. The MCU can discharge the first motor winding after the second switching tube is switched off, and at the moment, the first output voltage is the voltage of the first motor winding. Therefore, the first output voltage is always smaller than the power supply voltage, so that the charging system can perform voltage reduction conversion on the power supply voltage.

It should be noted that the charging system provided in the third aspect of the present application can also perform the step-up conversion on the power supply voltage. For example, the charging system may further include a fourth switch, a first terminal of the fourth switch is connected to the other end of the N motor windings, and a second terminal of the fourth switch is connected to the first power supply terminal. When the power supply voltage is less than the minimum charging voltage of the power battery, the MCU may turn on the first and second ends of the fifth switch, turn on the fourth switch, and turn off the sixth switch. And the MCU is used for conducting the second switching tube so as to charge the first motor winding corresponding to the first bridge arm. The MCU turns off the second switching tube to discharge the first motor winding.

Specifically, the MCU can charge the first motor winding after the second switching tube is conducted. The MCU can discharge the first motor winding after the second switching tube is switched off, and the first output voltage is the sum of the voltage of the first motor winding and the power supply voltage. It follows that the first output voltage is greater than the supply voltage, and therefore the charging system can up-convert the supply voltage.

In addition, the charging system provided in the third aspect of the present application may also perform buck-boost (buck-boost) conversion on the power supply voltage. For example, the charging system may further include a fourth switch, a first terminal of the fourth switch is connected to the other end of the N motor windings, and a second terminal of the fourth switch is connected to the first power supply terminal. The MCU may turn on the first terminal and the third terminal of the fifth switch and turn on the fourth switch. And the MCU is used for conducting the second switching tube so as to charge the first motor winding correspondingly connected with the first bridge arm. The MCU turns off the second switching tube to discharge the first motor winding.

Specifically, the MCU can charge the first motor winding after the second switching tube is conducted. The MCU can discharge the first motor winding after the second switching tube is switched off, and at the moment, the first output voltage is the voltage of the first motor winding. The voltage of the first motor winding is dependent upon the length of time that the first motor winding is charged, and therefore, by adjusting the length of time that the first motor winding is charged, the magnitude of the first output voltage, which may be greater than the supply voltage (step-up conversion) or less than the supply voltage (step-down conversion), may be adjusted.

It can be appreciated that the charging system provided by the third aspect of the present application is also compatible with the power battery matching scenario. For example, the MCU may further turn on the first terminal and the second terminal of the fifth switch and turn on the sixth switch when the power voltage is within the charging voltage range of the power battery. In this case, the power battery is directly connected to the dc power source and can directly receive the power voltage to complete the charging.

In a fourth aspect, the present application provides a charging system, which mainly includes a motor controller MCU and a motor. The MCU comprises N bridge arms, the motor comprises N motor windings, the N bridge arms and the N motor windings are respectively connected in a one-to-one correspondence mode, and N is an integer greater than or equal to 1. The high-potential ends of the N bridge arms are connected with a first battery end of the charging system, the first battery end can be connected with the anode of the power battery, and the power battery can output battery voltage to the charging system. The low potential ends of the N bridge arms are connected with a second battery end and a second power supply end of the charging system, the second battery end can be connected with the negative electrode of the power battery, the second power supply end can be connected with the negative electrode of the direct current load, and the direct current load can receive second output voltage of the charging system. One end of each of the N motor windings is connected with the middle point of the corresponding bridge arm, the other end of each of the N motor windings is connected with a first power supply end of the charging system, and the first power supply end can be connected with the positive electrode of the direct-current load. The voltage conversion circuit is formed by the N bridge arms and the N motor windings, when the battery voltage is larger than the maximum working voltage of the direct-current load, the MCU can perform voltage reduction conversion on the battery voltage through the voltage conversion circuit, and outputs the battery voltage subjected to voltage reduction conversion to the direct-current load as a second output voltage, wherein the second output voltage is not larger than the maximum working voltage of the direct-current load. And when the battery voltage is smaller than the minimum working voltage of the direct current load, performing boost conversion on the battery voltage through the voltage conversion circuit, and outputting the battery voltage subjected to boost conversion to the direct current load as a second output voltage, wherein the second output voltage is not smaller than the minimum working voltage of the direct current load.

Illustratively, any one of N bridge arms of the MCU is a first bridge arm, and the first bridge arm includes a first switching tube and a second switching tube, wherein a first electrode of the first switching tube is connected to the first battery terminal and the first power terminal, a second electrode of the first switching tube is connected to a first electrode of the second switching tube, and a midpoint of the first bridge arm is located between the first switching tube and the second switching tube. The charging system can further comprise a sixth switch and a fifth switch, wherein the first end of the fifth switch is connected with the second battery end, the second end of the fifth switch is connected with the low-potential ends of the N bridge arms, the third end of the fifth switch is connected with the other ends of the N motor windings, the first end of the sixth switch is connected with the first battery end, and the second end of the sixth switch is connected with the first power supply end.

Based on the charging system, when the battery voltage is less than the minimum working voltage of the direct current load, the MCU may turn on the sixth switch, and turn on the first terminal and the third terminal of the fifth switch. The MCU is used for conducting the first switching tube so as to charge the first motor winding correspondingly connected with the first bridge arm. The MCU turns off the first switch tube to discharge the first motor winding.

Specifically, the MCU can charge the first motor winding after turning on the first switching tube. The MCU can discharge the first motor winding after the first switching tube is switched off, and the second output voltage is the sum of the voltage of the battery and the voltage of the first motor winding. As can be seen, the second output voltage is greater than the battery voltage, and thus the charging system can up-convert the battery voltage.

It should be noted that the charging system provided in the fourth aspect of the present application can also perform voltage down conversion on the battery voltage. For example, the charging system may further include a fourth switch, a first terminal of the fourth switch is connected to the other end of the N motor windings, and a second terminal of the fourth switch is connected to the first power supply terminal. The MCU may turn on the first terminal and the second terminal of the fifth switch, turn on the fourth switch, and turn off the sixth switch when the battery voltage is greater than the maximum operating voltage of the DC load. The MCU is used for conducting the first switch tube so as to charge the first motor winding corresponding to the first bridge arm. And turning off the first switching tube to discharge the first motor winding.

Specifically, the MCU can charge the first motor winding after turning on the first switching tube, and the second output voltage is a voltage difference obtained by subtracting a voltage of the first motor winding from a battery voltage. The MCU can discharge the first motor winding after the first switching tube is switched off, and the second output voltage is the voltage of the first motor winding at the moment. It follows that the second output voltage is always less than the battery voltage, and therefore the charging system can down-convert the battery voltage.

In addition, the charging system provided by the fourth aspect of the present application can also perform buck-boost (buck-boost) conversion on the battery voltage. Illustratively, the charging system may further include a fourth switch, a first terminal of the fourth switch is connected to the other terminals of the N motor windings, and a second terminal of the fourth switch is connected to the first power supply terminal. The MCU may turn on the first terminal and the third terminal of the fifth switch and turn on the sixth switch. The MCU is used for conducting the first switch tube so as to charge the first motor winding correspondingly connected with the first bridge arm. The MCU turns off the first switch tube to discharge the first motor winding.

Specifically, the MCU can charge the first motor winding after turning on the first switching tube. The MCU can discharge the first motor winding after the first switching tube is switched off, and the second output voltage is the voltage of the first motor winding at the moment. The voltage of the first motor winding is dependent upon the length of time that the first motor winding is charged, and therefore, by adjusting the length of time that the first motor winding is charged, the magnitude of the second output voltage, which may be greater than the battery voltage (step-up conversion) or less than the battery voltage (step-down conversion), may be adjusted.

It can be appreciated that the charging system provided by the fourth aspect of the present application is also compatible with the situation that the battery voltage is matched with the dc load. For example, the MCU may further turn on the first terminal and the second terminal of the fifth switch and turn on the sixth switch when the battery voltage is within the operating voltage range of the dc load. In this case, the power battery is directly connected with the direct current load, and can directly supply power to the direct current load.

In a fifth aspect, the present application provides an electric vehicle, which mainly includes a power battery and the charging system provided in any one of the first to fourth aspects, and the charging system can charge the power battery.

These and other aspects of the present application will be more readily apparent from the following description of the embodiments.

Drawings

FIG. 1 is a schematic view of an electric vehicle charging scenario;

FIG. 2 is a schematic diagram of an electric drive system;

fig. 3 is a schematic diagram of a charging system according to an embodiment of the present disclosure;

fig. 4 is one of the boost conversion states of the charging system provided by the embodiment of the present application;

fig. 5 shows a second boost conversion state of the charging system according to the embodiment of the present application;

fig. 6 is a schematic diagram of a specific charging system according to an embodiment of the present disclosure;

fig. 7 is a schematic diagram of a specific charging system according to an embodiment of the present disclosure;

fig. 8 is a diagram illustrating one of buck conversion states of a charging system according to an embodiment of the present disclosure;

fig. 9 shows a second buck conversion state of the charging system according to the embodiment of the present application;

fig. 10 is a schematic diagram of an exemplary charging system according to an embodiment of the present disclosure;

fig. 11 is a diagram illustrating one of the switch states of the charging system according to the embodiment of the present application;

fig. 12 shows a third step-down conversion state of the charging system according to the embodiment of the present application;

fig. 13 is a fourth step-down conversion state of the charging system according to the embodiment of the present application;

fig. 14 shows a second switch state of the charging system according to the embodiment of the present application;

fig. 15 shows a third switch state of the charging system according to the embodiment of the present application;

fig. 16 shows one of buck-boost transition states of the charging system according to the embodiment of the present application;

fig. 17 shows a second buck-boost conversion state of the charging system according to the embodiment of the present application;

fig. 18 shows a third boost conversion state of the charging system according to the embodiment of the present application;

fig. 19 is a fourth step-up conversion state of the charging system according to the embodiment of the present application;

fig. 20 shows a third buck-boost conversion state of the charging system according to the embodiment of the present application;

fig. 21 is a block-boost conversion state of the charging system according to the fourth embodiment of the present disclosure;

fig. 22 is a schematic diagram of another charging system provided in the embodiment of the present application;

fig. 23 shows a fourth state of a charging system according to the present embodiment;

fig. 24 shows a fifth step-down conversion state of the charging system according to the embodiment of the present application;

fig. 25 shows a sixth step-down conversion state of the charging system according to the embodiment of the present application;

fig. 26 shows a fifth switching state of the charging system according to the embodiment of the present application;

fig. 27 shows a sixth on-off state of the charging system according to the embodiment of the present application;

fig. 28 shows five buck-boost conversion states of the charging system according to the embodiment of the present application;

fig. 29 shows a sixth state of buck-boost transition of the charging system according to the embodiment of the present application;

fig. 30 shows a fifth step-up conversion state of the charging system according to the embodiment of the present application;

fig. 31 shows a sixth boost conversion state of the charging system according to the embodiment of the present application;

fig. 32 is a seventh exemplary embodiment of a buck-boost transition state of the charging system;

fig. 33 shows an eighth buck-boost conversion state of the charging system according to the embodiment of the present application.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more clear, the present application will be further described in detail with reference to the accompanying drawings. The particular methods of operation in the method embodiments may also be applied to apparatus embodiments or system embodiments. It is to be noted that "at least one" in the description of the present application means one or more, where a plurality means two or more. In view of this, the "plurality" may also be understood as "at least two" in the embodiments of the present invention. "and/or" describes the association relationship of the associated objects, meaning that there may be three relationships, e.g., a and/or B, which may mean: a exists alone, A and B exist simultaneously, and B exists alone. In addition, the character "/" generally indicates that the preceding and following related objects are in an "or" relationship, unless otherwise specified. In addition, it is to be understood that the terms first, second, etc. in the description of the present application are used for distinguishing between the descriptions and not necessarily for describing a sequential or chronological order.

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application.

An electric vehicle, which may also be referred to as a new energy vehicle, is a vehicle driven by electric energy. As shown in fig. 1, an electric vehicle 10 mainly includes a power battery 12, a motor 13, and wheels 14. The power battery 12 is a high-capacity and high-power storage battery. When the electric vehicle 10 runs, the power battery 12 may supply power to the motor 13 through a Motor Control Unit (MCU) 111, and the motor 13 converts the electric energy provided by the power battery 12 into mechanical energy, so as to drive the wheels 14 to rotate, thereby implementing the running of the vehicle.

When the electric vehicle 10 is charged, the electric vehicle 10 can be charged through the charging pile 20. As shown in fig. 1, the charging pile 20 mainly includes a power supply circuit 21 and a charging gun 22. One end of the power supply circuit 21 is connected with the power frequency power grid 30, and the other end is connected with the charging gun 22 through a cable. At present, charging pile 20 is mostly the direct current charging pile, and power supply circuit 21 can convert the alternating current that power frequency electric wire netting 30 provided into the direct current. An operator can insert the charging gun 22 into the charging socket of the electric vehicle 10, so that the charging gun 22 is connected with the power battery 12 in the electric vehicle 10, and the power circuit 21 of the charging pile 20 can further charge the power battery 12 through the charging gun 22.

The output voltage of the charging pile 20 can be understood as the power supply voltage received by the electric vehicle 10. Under the dc fast charging scene, the power voltage received by the electric vehicle 10 is within the charging voltage range of the power battery 12, and the power battery 12 can directly use the output voltage of the charging pile 20 to complete charging.

The lower limit of the charging voltage range of the power battery 12 is the minimum charging voltage, which can be understood as the minimum value of the charging voltage that the power battery 12 can adapt to. The upper limit of the charging voltage range of the power battery 12 is the maximum charging voltage, which can be understood as the maximum value of the charging voltage that the power battery 12 can adapt to.

At present, in order to increase the charging speed of the electric vehicle 10, the voltage level of the power battery 12 is gradually increased from 500V to 800V, for example, the battery voltage of the power battery 12 can reach 800V for the power battery 12 with the voltage level of 800V, and the required charging voltage is often not lower than 800V. However, the voltage level of the charging pile 20 supporting the dc quick charging in the current market is generally 500V, that is, the maximum output voltage of most charging piles 20 supporting the dc quick charging is 500V. This makes charging difficult for many electric vehicles 10 equipped with high voltage power batteries.

In view of this, the present embodiment provides a charging system 11, and the charging system 11 is connected to a power battery 12. The charging system 11 may receive a power supply voltage when charging the electric vehicle 10. When the power supply voltage is less than the minimum charging voltage of the power battery 12, the charging system 11 may up-convert the power supply voltage and supply the up-converted power supply voltage to the power battery 12 as the first output voltage.

In the above example, the output voltage of the charging pile 20 is 500V, that is, the power supply voltage received by the charging system 11 is 500V. Assuming that the charging voltage that the power battery 12 can adapt to is 960V, the charging system 11 may up-convert the supply voltage to 960V, thereby providing the power battery 12 with a first output voltage of 960V, so that the power battery 12 may complete charging with the first output voltage.

It should be noted that, in order to save the space occupied by the charging system 11 in the electric vehicle 10 and control the cost of the charging system 11, the charging system 11 in the embodiment of the present application may be implemented by multiplexing the MCU111 in the electric vehicle 10 and the motor winding in the motor 13. The charging system 11 including the MCU111 and the motor 13 may also be referred to as an electric drive system of the electric vehicle 10.

Specifically, the motor 13 relies on electromagnetic induction effects to achieve conversion of electrical energy to mechanical energy, and thus motor windings are provided in the motor 13. Currently, the number of motor windings in the motor 13 is mostly 3 or 6. Taking a three-phase motor as an example, as shown in fig. 2, the MCU111 includes three bridge arms, the motor 13 includes three motor windings (N1 to N3), and the three bridge arms in the MCU111 are connected to the three motor windings in the motor 13 in a one-to-one correspondence. Wherein:

the first bridge arm comprises a switching tube T1 and a switching tube T2, a first electrode of the switching tube T1 is used for being connected with the positive electrode of the power battery 12, a second electrode of the switching tube T1 is connected with a first electrode of the switching tube T2, and a second electrode of the switching tube T2 is used for being connected with the negative electrode of the power battery 12. The middle point of the first leg is the connection point between the switching tube T1 and the switching tube T2. The middle point of the first leg is connected to one end of the motor winding N1.

The second bridge arm comprises a switching tube T3 and a switching tube T4, a first electrode of the switching tube T3 is used for being connected with the positive electrode of the power battery 12, a second electrode of the switching tube T3 is connected with a first electrode of the switching tube T4, and a second electrode of the switching tube T4 is used for being connected with the negative electrode of the power battery 12. The middle point of the second leg is the connection point between the switching tube T3 and the switching tube T4. The middle point of the second leg is connected to one end of the motor winding N2.

The third bridge arm comprises a switching tube T5 and a switching tube T6, a first electrode of the switching tube T6 is used for being connected with the positive electrode of the power battery 12, a second electrode of the switching tube T3 is connected with a first electrode of the switching tube T4, and a second electrode of the switching tube T4 is used for being connected with the negative electrode of the power battery 12. The middle point of the third leg is the connection point between the switching tube T5 and the switching tube T6. The middle point of the third bridge arm is connected with one end of a motor winding N3, and the other ends of the three motor windings are connected.

The MCU111 further includes a control board (not shown). The control board is respectively connected with control electrodes from a switch tube T1 to a switch tube T6, and respectively controls the on and off of a switch tube T1 to a switch tube T6, so that three bridge arms can convert the battery voltage output by the power battery 12 into three-phase alternating current, and each bridge arm corresponds to one phase of the three-phase alternating current. The MCU111 outputs the three-phase ac power to the motor 13, so that the motor windings N1 to N3 generate a spatial rotating magnetic field, thereby driving the motor rotor to rotate, and further converting the electric power into mechanical power.

It should be noted that the switch tube in the embodiment of the present application may be one or more of various types of switch tubes, such as a relay, a Metal Oxide Semiconductor Field Effect Transistor (MOSFET), a Bipolar Junction Transistor (BJT), an Insulated Gate Bipolar Transistor (IGBT), etc., which are not listed in the embodiment of the present application. Each switching tube may include a first electrode, a second electrode, and a control electrode, wherein the control electrode is used to control the switching tube to be turned on or off. When the switching tube is switched on, current can be transmitted between the first electrode and the second electrode of the switching tube, and when the switching tube is switched off, current cannot be transmitted between the first electrode and the second electrode of the switching tube. Taking the IGBT as an example, in the embodiment of the present application, the first electrode of the switching tube may be a collector, the second electrode may be an emitter, and the control electrode may be a gate electrode.

Generally, as shown in fig. 2, a switch K2 and a switch K5 may be further disposed between the power battery 12 and the MCU 111. For example, the switches K2 and K5 may be relays. The switch tube K2 and the switch tube K5 may be integrated with the power battery 12 in a battery pack, or may be provided independently, which is not limited in this embodiment.

One end of the switch K2 is connected with the anode of the power battery 12, and the other end of the switch K2 is connected with the high-potential ends of the three bridge arms. One end of the switch K5 is connected with the cathode of the power battery 12, and the other end of the switch K5 is connected with the low-potential ends of the three bridge arms. When the switch K2 and the switch K5 are turned on, the power battery 12 can supply power to the MCU 111. When the switch K2 and the switch K5 are turned off, the power battery 12 stops supplying power to the MCU 111.

As can be seen from the above description of the MCU111 and the motor 13, the MCU111 includes N bridge arms, the motor 13 includes N windings, the N bridge arms and the N windings are respectively connected in a one-to-one correspondence, and N is an integer greater than or equal to 1. It is understood that the electric vehicle 10 is not required to be moved when the electric vehicle 10 is charged, i.e. the MCU111 is not required to provide three phases of power to the motor 13. Therefore, the embodiment of the application can multiplex the charging of the N arms in the MCU and the N motor windings in the motor 13 without affecting the driving function of the electric vehicle 10.

Next, the charging system 11 provided in the embodiment of the present application is further exemplified by the following examples.

Example one

Illustratively, the charging system 11 provided in the embodiment of the present application includes an MCU111 and a motor 13. The MCU111 includes N bridge arms, the motor 13 includes N motor windings, the N bridge arms and the N motor windings are respectively connected in a one-to-one correspondence, and N is an integer greater than or equal to 1.

Taking N-3 as an example, as shown in fig. 3, the charging system 11 includes the MCU111 and the motor 13. The first battery end of the charging system 11 is connected with the positive pole of the power battery 12, the second battery end is connected with the negative pole of the power battery 12, the first power supply end of the charging system 11 is connected with the positive pole of the direct-current power supply, and the second power supply end of the charging system is connected with the negative pole of the direct-current power supply.

The direct-current power supply can be a charging pile, another electric vehicle and the like, and the embodiment of the application is not limited to the above. The dc power supply may output a supply voltage. The charging system 11 receives the power voltage through the first power terminal and the second power terminal, converts the power voltage into a first output voltage adapted to the power battery 12, and outputs the first output voltage to the power battery 12 through the first battery terminal and the second battery terminal. The power battery 12 can receive the first output voltage provided by the charging system 11, thereby completing the charging.

Specifically, as shown in fig. 3, the MCU111 includes three bridge arms, the motor 13 includes three motor windings (N1 to N3), and the three bridge arms in the MCU111 are respectively connected to the motor windings N1 to N3 in a one-to-one correspondence manner, which is the same as that in fig. 2 and is not described again.

In the embodiment of the application, the high potential ends of the three bridge arms in the MCU111 are further connected to a first power supply terminal, and the connection point of the motor windings N1-N3 is further connected to a second power supply terminal. In this case, the three arms in the MCU111 and the motor windings N1 to N3 may form a voltage conversion circuit, so that the MCU111 may control the on and off of each of the switching tubes T1 to T6 to convert the power supply voltage.

Therefore, when the power supply voltage is less than the minimum charging voltage of the power battery 12, the MCU111 may perform step-up conversion of the power supply voltage by the voltage conversion circuit and output the step-up converted power supply voltage to the power battery as a first output voltage that is not less than the minimum charging voltage of the power battery 12.

For example, the power supply voltage is 500V, and the minimum charging voltage of the power battery 12 is 960V. The MCU111 may boost the power voltage to 960V or above 960V to provide the power battery 12 with the adapted first output voltage, so that the power battery 12 may complete charging.

Generally, as shown in fig. 3, the charging system 11 further includes a switch K3 and a switch K4. The switch K3 and the switch K4 may also be referred to as fast contactors. One end of the switch K3 is connected with the connection point of the motor windings N1 to N3, and the other end of the switch K3 is connected with a second power supply end. One end of the switch K4 is connected with the high potential ends of the three bridge arms, and the other end of the switch K4 is connected with the first power supply end. When the switch K3 and the switch K4 are turned on, the dc power supply may supply power to the charging system 11. When the switch K3 and the switch K4 are turned off, the dc power supply may stop supplying power to the charging system 11.

Next, taking the bridge arm 3 including the switching tube T5 and the switching tube T6 as an example, the process of step-up conversion will be further exemplified. The middle point of the bridge arm 3 is the connection point of the switching tube T5 and the switching tube T6. The middle point of the bridge arm 3 is connected with one end of a motor winding N3, and the other end of the motor winding N3 is connected with a second power supply end. When the power supply voltage is subjected to boost conversion, the method mainly comprises the following two stages:

stage one: charging of the motor winding N3

The MCU111 can turn on the switching tube T5 to charge the motor winding N3 correspondingly connected to the arm 3. It can be understood that the switch tube T6 is turned off at this time. As shown in fig. 4, current is input from the first power terminal, passes through the switch T5, and reaches the motor winding N3, thereby charging the motor winding N3.

And a second stage: discharge of motor winding N3

The MCU111 may turn off the switch T5, and the motor winding N3 cannot continue to receive current through the switch T5. The motor winding N3 begins to discharge due to the freewheeling characteristics of the inductance. As shown in fig. 5, the current is output from the end of the motor winding N3 close to the second power supply end, and is transmitted through the dc power supply, the power battery 12 and the diode in the switch tube T6, and then flows back to the end of the motor winding N3 close to the second switch tube. In this process, the first output voltage of the charging system 11 is the sum of the supply voltage of the dc power supply and the voltage of the motor winding N3. It is understood that the first output voltage is greater than the supply voltage of the dc power supply, thereby achieving a boost conversion.

It can be understood that, when the power of the dc power supply is large, the MCU111 may also synchronously control the plurality of arms to perform the step-up conversion. For example, the MCU111 can synchronously control the on and off of the switching tube T1, the switching tube T3 and the switching tube T5, so that the motor windings N1 to N3 can be charged and discharged synchronously, in this case, it is equivalent to three motor windings working in parallel, thereby supporting the voltage conversion in the high power scenario.

To sum up, the charging system 11 in the embodiment of the present application can perform the step-up conversion on the power supply voltage of the dc power supply, so as to charge the high-voltage power battery 12, which is beneficial to improving the convenience of charging the high-voltage power battery 12. Meanwhile, the embodiment of the application realizes the charging system 11 by multiplexing the N bridge arms in the MCU111 and the N motor windings in the motor 13, and is also favorable for reducing the space and the cost occupied by the charging system 11.

It will be appreciated that the supply voltage provided by the dc power supply may also be within the charging voltage range of the power cell 12. For example, the charging voltage range of the power battery 12 is 700-1000V, and the power voltage of the dc power supply (charging pile) is also 800V, in which case the power voltage does not need to be boosted.

In order to accommodate this scenario, as shown in fig. 6, the charging system 11 provided in the embodiment of the present application may further include a switch K1. The first terminal of the switch K1 is connected to the second battery terminal, and the second terminal of the switch K1 is connected to the second power supply terminal. The MCU111 can control the on and off of the switch K1, and specifically, the MCU111 can turn on the switch K1 when the power voltage is within the charging voltage range of the power battery 12, and turn off the switch K1 when the power voltage is outside the charging voltage range of the power battery 12.

The scene in which the power supply voltage is within the charging voltage range of the power battery 12 may be a scene in which the power supply voltage is equal to the minimum charging voltage of the power battery 12, a scene in which the power supply voltage is equal to the maximum charging voltage of the power battery 12, or a scene in which the power supply voltage is greater than the minimum charging voltage of the power battery 12 and is less than the maximum charging voltage of the power battery 12. The scenario in which the power supply voltage is outside the charging voltage range of the power battery 12 may be a scenario in which the power supply voltage is less than the minimum charging voltage of the power battery 12, or a scenario in which the power supply voltage is greater than the maximum charging voltage of the power battery 12.

As shown in fig. 6, the switch K5 is turned on by default when the power battery 12 is being charged. When the switch K1 is turned on, the power battery 12 can be directly connected to the dc power source, and therefore can directly receive the power voltage provided by the dc power source to complete charging. Therefore, the MCU111 can turn on the switch K1 when the power supply voltage is within the charging voltage range of the power battery 12.

When the switch K1 is turned off, the charging system 11 shown in fig. 6 is equivalent to the charging system 11 shown in fig. 3, and the MCU111 may perform boost conversion on the power supply voltage, which is not described in detail again.

In a possible implementation manner, as shown in fig. 3, the charging system 11 may further include a filter capacitor C1, one end of the filter capacitor C1 is connected to the first battery terminal, and the filter capacitor is

The other end of C1 is connected to the second battery terminal. The filter capacitor C1 may filter the first output voltage when charging the power cell 12.

Similarly, as shown in fig. 3, the charging system 11 may further include a filter capacitor C2, one end of the filter capacitor C2 being connected to the first power supply terminal, and the other end of the filter capacitor C2 being connected to the second power supply terminal. The filter capacitor C2 may filter the received supply voltage when charging the power cell 12.

As described above, the motor windings N1 to N3 need to store electric energy when performing the step-up conversion. However, in some machines the inductance of the motor windings N1 through N3 may not be sufficient to support the boost conversion. In view of this, as shown in fig. 7, the charging system 11 may further include an inductor L1, one end of the inductor L1 is connected to the connection point of the N motor windings, and the other end of the inductor L1 is connected to the second power supply terminal.

Taking motor winding N3 as an example, inductor L1 may also be charged when motor winding N3 is charged. When the motor winding N3 is discharging, the inductor L1 may also be discharging, and at this time, the first output voltage of the charging system 11 is the sum of the power supply voltage, the voltage of the motor winding N3, and the voltage of the inductor L1. It can be seen that the increase of the inductance L1 is beneficial to increase the first output voltage, so that the first output voltage can be matched with the power battery 12.

Example two

With the development of the charging and discharging technology of the electric vehicle 10, more and more electric vehicles 10 can also support the discharging function, that is, the electric vehicles 10 supply power to the dc load. In some scenarios, the dc load may be another electric vehicle. For example, as shown in fig. 3, the first power supply terminal of the charging system 11 may be further connected to the positive electrode of the dc load, and the second power supply terminal of the charging system 11 may be further connected to the negative electrode of the dc load.

The power battery 12 may output a battery voltage to the charging system 11. When the battery voltage of the power battery 12 is greater than the maximum operating voltage of the dc load, the charging system 11 may perform step-down conversion on the battery voltage, and output the step-down converted battery voltage as a second output voltage to the dc load. The second output voltage is not greater than the maximum operating voltage of the DC load. When the direct-current load is another electric vehicle, the maximum working voltage of the direct-current load can be understood as the maximum charging voltage of the power battery in the other electric vehicle.

For example, the battery voltage of the power battery 12 is 800V, and the operating voltage range of the dc load is 400-. The charging system 11 outputs the second output voltage to the dc load, so as to provide an adapted voltage for the dc load.

Next, taking the bridge arm 3 including the switching tube T5 and the switching tube T6 in fig. 3 as an example, the process of the step-up conversion will be further exemplified. It is understood that the switches K2 to K5 are turned on at this time, and the description thereof is omitted. When the voltage of the battery is subjected to voltage reduction conversion, the method mainly comprises the following two stages:

stage one: charging of the motor winding N3

The MCU111 turns on the switch transistor T6, and the switch transistor T5 remains off. As shown in fig. 8, the current is output from the positive electrode of the power battery 12, transmitted through the dc load, the motor winding N3 and the switching tube T6, and then returned to the negative electrode of the power battery 12. During this phase, the motor winding N3 is charged. The second output voltage output by the charging system 11 is the difference between the battery voltage and the voltage of the motor winding N3. Obviously, the second output voltage is smaller than the battery voltage, so the charging system 11 can implement the step-down conversion of the battery voltage.

And a second stage: discharge of motor winding N3

The MCU111 can turn off the switching tube T6 and the charging loop of the motor winding N3. The motor winding N3 begins to discharge due to the freewheeling characteristics of the inductance. As shown in fig. 9, the current is output from the end of the motor winding N3 close to the switch tube T5, and is transmitted through the diode in the switch tube T5 and the dc load, and then flows back to the end of the motor winding N3 close to the second power supply end. In this process, the second output voltage of the charging system 11 is the voltage of the motor winding N3. Obviously, the voltage of the motor winding N3 is less than the battery voltage, so the charging system 11 can perform a step-down conversion of the battery voltage.

It can be understood that, when the output power of the power battery 12 is large, the MCU111 may also synchronously control a plurality of arms to perform the step-up conversion. For example, the MCU111 can synchronously control the on and off of the switching tube T2, the switching tube T4 and the switching tube T6, so that the motor windings N1 to N3 can be charged and discharged synchronously, in this case, it is equivalent to three motor windings working in parallel, thereby supporting the voltage conversion in the high power scenario.

It should be noted that the charging system 11 shown in fig. 6 and 7 is also applicable to the step-down conversion of the battery voltage, and details thereof are not repeated.

Taking fig. 6 as an example, when the battery voltage is within the working voltage range of the dc load, the MCU111 may turn on the switch K1, so that the power battery 12 may directly supply power to the dc load. When the battery voltage is outside the operating voltage range of the dc load, the MCU111 may turn off the switch K1, so that the MCU111 may perform voltage conversion on the battery voltage.

The battery voltage is within the working voltage range of the dc load, which may be a scenario in which the battery voltage is equal to the minimum working voltage of the dc load, a scenario in which the battery voltage is equal to the maximum working voltage of the dc load, or a scenario in which the battery voltage is greater than the minimum working voltage of the dc load and less than the maximum working voltage of the dc load. The battery voltage is out of the working voltage range of the direct current load, which may be a scenario in which the battery voltage is less than the minimum working voltage of the direct current load, or a scenario in which the battery voltage is greater than the maximum working voltage of the direct current load.

EXAMPLE III

As mentioned previously, there are both low-voltage charging piles and high-voltage charging piles in the current market. The electric vehicle 10 may be provided with both a high-voltage power battery and a low-voltage power battery. Therefore, it would also be a common scenario for a high voltage charging pile to charge a low voltage power battery.

In view of this, the present embodiment further provides a charging system 11, and the connection relationship between the charging system 11 and the dc power source and the power battery 12 is the same as that in the above embodiments, and details thereof are not repeated. When the power supply voltage of the dc power supply is greater than the maximum charging voltage of the power battery 12, the charging system 11 may perform step-down conversion on the power supply voltage, so as to provide the power battery 12 with a first output voltage that is not greater than the maximum charging voltage. When the power supply voltage of the dc power supply is less than the minimum charging voltage of the power battery 12, the charging system 11 may perform step-up conversion on the power supply voltage, so that the power battery 12 may be provided with a first output voltage not less than the minimum charging voltage.

For example, as shown in fig. 10, the charging system 11 in the embodiment of the present application may be implemented by multiplexing N bridge arms in the MCU111 and N motor windings in the motor 13, where N is 3 in fig. 10 as an example, and circuit structures of the N bridge arms and the N motors are not repeated. Further, the charging system 11 may further include a switch K1 and a switch K2. The first terminal of the switch K1 is connected to the second battery terminal of the charging system 11, and the second terminal of the switch K1 is connected to the second power source terminal. The switch K2 is a single-pole double-throw switch, wherein the first end of the switch K2 is connected to the first battery terminal, the second end a of the switch K2 is connected to the connection points of the N motor windings, and the third end b of the switch K2 is connected to the first power supply terminal.

It should be noted that the switch K2 may be provided independently of the power cell 12. In this case, the first terminal of the switch K2 may be understood as the first battery terminal of the charging system 11. It is understood that the switch K2 may also be integrated with the power battery 12 in a power battery pack, in which case, the charging system 11 provided in the embodiment of the present application may be considered to include two first battery terminals, one of the first battery terminals is connected to the second terminal a of the switch K2, and the other first battery terminal is connected to the third terminal b of the switch K2.

Next, the step-down conversion and the step-up conversion of the power supply voltage will be described by taking fig. 10 as an example.

Step-down conversion

During the step-down conversion, the MCU111 may turn on the switch K1 and turn on the first terminal a and the second terminal a of the switch K2, and the circuit state may be as shown in fig. 11. It is noted that, in some scenarios, the charging system 11 may further be provided with switches K3 to K5, in which case the switches K4 and K5 should be kept on, and the switch K3 should be kept off. Based on the circuit state shown in fig. 11, taking the bridge arm 3 including the switching tube T5 and the switching tube 6 as an example, the step-down conversion process mainly includes:

stage one: charging of the motor winding N3

The MCU111 turns on the switching tube T5 to charge the motor winding N3. As shown in fig. 12, the current is output from the positive electrode of the dc power supply, and after passing through the switching tube T5, the motor winding N3, the switch K2, and the power battery 12, the current flows back to the negative electrode of the dc power supply, thereby forming a charging circuit to charge the motor winding N3. In this process, the first output voltage of the charging system 11 is the difference of the power supply voltage minus the voltage of the motor winding N3. Obviously, the first output voltage is smaller than the power supply voltage, so the charging system 11 can implement step-down conversion.

And a second stage: discharge of motor winding N3

The MCU111 turns off the switching tube T5 to discharge the motor winding N3. Specifically, after the MCU111 turns off the switching tube T5, the charging loop is turned off. The motor winding N3 discharges due to the freewheeling characteristic of the inductance. As shown in fig. 13, the current is output from the end of the motor winding N3 close to the second power supply end, and after passing through the switch K2, the power battery 12 and the diode in the switch tube T6, the current flows back to the end of the motor winding N3 close to the switch tube T6. In this process, the first output voltage of the charging system 11 is the voltage of the motor winding N3. Obviously, the first output voltage is smaller than the power supply voltage, so the charging system 11 can perform step-down conversion on the power supply voltage.

Step two, boost conversion

As shown in fig. 10, the charging system 11 may further include a switch K3. A first terminal of the switch K3 is connected to the connection point of the motor windings N1 to N3, and a second terminal of the switch K3 is connected to a second power supply terminal. During the step-up conversion, the MCU111 may turn on the first terminal and the third terminal b of the switch K2, turn on the switch K3, and turn off the switch K1, and the circuit state may be as shown in fig. 14. As can be seen from fig. 14, the circuit state in this case is equivalent to the charging system 11 shown in fig. 3, and therefore reference may be made to the step-up conversion process provided in the first embodiment, which is not described again.

In addition, the charging system 11 shown in fig. 10 can also support voltage conversion in a buck-boost (buck-boost) mode for the power supply voltage. Specifically, the method comprises the following steps:

third, buck-boost

When buck-boost conversion is performed on the power supply voltage, the MCU111 may turn on the first terminal and the second terminal a of the switch K2 and turn on the switch K3, and the circuit state may be as shown in fig. 15. Based on the circuit state shown in fig. 15, the buck-boost conversion mainly includes the following two stages:

stage one: charging of the motor winding N3

The MCU111 turns on the switching tube T5 to charge the motor winding N3. As shown in fig. 16, the current is output from the positive electrode of the dc power supply, transmitted through the switching tube T5 and the motor winding N3, and then returned to the negative electrode of the dc power supply, thereby forming a charging circuit of the motor winding N3.

And a second stage: discharge of motor winding N3

The MCU111 turns off the switching tube T5 to discharge the motor winding N3. As shown in fig. 17, the current is output from the end of the motor winding N3 close to the second power supply end, and after passing through the switch K2, the power battery 12 and the diode in the switch tube T6, the current flows back to the end of the motor winding N3 close to the switch tube T6. It can be seen that the first output voltage of the charging system 11 is equal to the voltage of the motor winding N3. The MCU111 controls the voltage of the motor winding N3 by controlling the charging time of the motor winding N3 during phase one, thereby controlling the magnitude of the first output voltage, which may be either greater than or less than the supply voltage.

Similar to the embodiment, when the power voltage of the dc power supply is within the charging voltage range of the power battery 12, the MCU111 may also turn on the first terminal and the third terminal b of the switch K2 and turn on the switch K1, so that the power battery 12 may directly receive the power voltage, thereby completing the charging. For specific implementation, reference may be made to the first embodiment, which is not described again.

Example four

It should be noted that the charging system 11 shown in fig. 10 can also support the discharging function of the electric vehicle 10. When the electric vehicle 10 is discharged, the connection relationship between the charging system 11, the power battery 12 and the dc load is similar to that in the second embodiment, and the description thereof is omitted.

The difference from the second embodiment is that the charging system 10 provided in fig. 10 can not only perform voltage-down conversion on the battery voltage, but also perform voltage-up conversion on the battery voltage, so that the battery voltages output by the high-voltage power battery and the low-voltage power battery can both adapt to the dc loads with different operating voltage ranges.

Next, with reference to fig. 10 as an example, the voltage up-conversion and the voltage down-conversion of the battery voltage will be described.

One, boost conversion

During the step-up conversion, the MCU111 may turn on the switch K1, and turn on the first terminal and the second terminal a of the switch K2, and the circuit state may be as shown in fig. 11. Based on the circuit state shown in fig. 11, taking bridge arm 3 including switching tube T5 and switching tube 6 as an example, the step-up conversion process mainly includes:

stage one: charging of the motor winding N3

The MCU111 turns on the switching tube T6 to charge the motor winding N3. As shown in fig. 18, the current is output from the positive electrode of the power battery 12, transmitted through the switch K2, the motor winding N3 and the switching tube T6, and then returned to the negative electrode of the power battery 12, thereby forming a charging circuit to charge the motor winding N3.

And a second stage: discharge of motor winding N3

The MCU111 turns off the switching tube T6 to discharge the motor winding N3. After the MCU111 turns off the switching tube T6, the charging loop is turned off. The motor winding N3 discharges due to the freewheeling characteristic of the inductance. As shown in fig. 19, the current is output from the positive electrode of the power battery 12, transmitted through the switch K2, the motor winding N3, the diode in the switching tube T5, and the dc load, and then returned to the negative electrode of the power battery 12. In this process, the second output voltage of the charging system 11 is the sum of the battery voltage of the power battery 12 and the voltage of the motor winding N3. Obviously, the second output voltage is greater than the battery voltage, so the charging system 11 can perform a step-up conversion on the battery voltage.

Step two, step-down conversion

As shown in fig. 10, the charging system 11 may further include a switch K3. A first terminal of the switch K3 is connected to the connection point of the motor windings N1 to N3, and a second terminal of the switch K3 is connected to a second power supply terminal. During the step-down conversion process, the MCU111 may turn on the first terminal and the third terminal b of the switch K2, turn on the switch K3, and turn off the switch K1, and the circuit state may be as shown in fig. 14. As can be seen from fig. 14, the circuit state in this case is equivalent to the charging system 11 shown in fig. 3, so that reference may be made to the step-down conversion process provided in the second embodiment, which is not repeated herein.

In addition, the charging system 11 shown in fig. 10 can also support buck-boost mode voltage conversion on the battery voltage. Specifically, the method comprises the following steps:

third, buck-boost

When buck-boost conversion is performed on the battery voltage, the MCU111 may turn on the first terminal and the second terminal a of the switch K2 and turn on the switch K3, and the circuit state may be as shown in fig. 15. Based on the circuit state shown in fig. 15, the buck-boost conversion mainly includes the following two stages:

stage one: charging of the motor winding N3

The MCU111 turns on the switching tube T6 to charge the motor winding N3. As shown in fig. 20, the current is output from the positive electrode of the power battery 12, transmitted through the switch K2, the motor winding N3 and the switch tube T6, and then flows back to the negative electrode of the power battery 12, thereby forming a charging loop of the motor winding N3.

And a second stage: discharge of motor winding N3

The MCU111 turns off the switching tube T6 to discharge the motor winding N3. As shown in fig. 21, the current is output from the end of the motor winding N3 close to the switch tube T5, and after passing through the diode in the switch tube T5 and the dc load, flows back to the end of the motor winding N3 close to the second power supply terminal. It can be seen that the second output voltage of the charging system 11 is equal to the voltage of the motor winding N3. The MCU111 controls the voltage of the motor winding N3 by controlling the charging time of the motor winding N3 during phase one, thereby controlling the magnitude of the second output voltage, which may be either greater than or less than the battery voltage.

Similar to the second embodiment, when the battery voltage of the power battery 12 is within the operating voltage range of the dc load, the MCU111 may also turn on the first terminal and the third terminal b of the switch K2 and turn on the switch K1, so that the power battery 12 can directly supply power to the dc load. For specific implementation, reference may be made to embodiment two, which is not described again.

EXAMPLE five

In the third and fourth embodiments, the connection points of the N motor windings are connected to the second supply terminal. Based on a similar concept, the connection points of the N motor windings may also be connected to the first power supply terminal, in which case the charging system 11 may be as shown in fig. 22.

The charging system 11 further includes a switch K5 and a switch K6. The switch K5 is a single-pole double-throw switch, a first end of the switch K5 is connected with a second battery end, a second end a of the switch K5 is connected with low-potential ends of the N bridge arms, a third end b of the switch K5 is connected with connection points of the N motor windings, a second end of the switch K6 is connected with a second power supply end, a first end of the switch K6 is connected with a first battery end, and a second end of the switch K6 is connected with the first power supply end.

It should be noted that the switch K5 may be provided independently of the power cell 12. In this case, the first terminal of the switch K5 may be understood as the second battery terminal of the charging system 11. It is understood that the switch K5 may also be integrated with the power battery 12 in a power battery pack, in which case, the charging system 11 provided in the embodiment of the present application may be considered to include two second battery terminals, one of the second battery terminals is connected to the second terminal a of the switch K5, and the other second battery terminal is connected to the third terminal b of the switch K5.

Next, the step-down conversion and the step-up conversion of the power supply voltage will be described by taking fig. 22 as an example.

Step-down conversion

When the power supply voltage is greater than the maximum charging voltage of the power battery 12, the MCU111 may down-convert the power supply voltage. During the step-down conversion, the MCU111 may turn on the switch K6, and turn on the first terminal and the third terminal b of the switch K5, and the circuit state may be as shown in fig. 23. It is noted that, in some scenarios, the charging system 11 may further be provided with switches K2 to K4, in which case the switches K2 and K3 should be kept on, and the switch K4 should be kept off. Based on the circuit state shown in fig. 23, taking the bridge arm 3 including the switching tube T5 and the switching tube 6 as an example, the step-down conversion process mainly includes:

stage one: charging of the motor winding N3

The MCU111 turns on the switching tube T6 to charge the motor winding N3. As shown in fig. 24, the current is output from the positive pole of the dc power supply, transmitted through the power battery 12, the switch K5, the motor winding N3 and the switching tube T6, and then returned to the negative pole of the dc power supply, thereby forming a charging circuit to charge the motor winding N3. In this process, the first output voltage of the charging system 11 is the difference of the power supply voltage minus the voltage of the motor winding N3. Obviously, the first output voltage is smaller than the power supply voltage, so the charging system 11 can implement step-down conversion.

And a second stage: discharge of motor winding N3

The MCU111 turns off the switching tube T6 to discharge the motor winding N3. And turning off the second switching tube to discharge the first motor winding. Specifically, after the MCU111 turns off the switching tube T6, the charging loop is turned off. The motor winding N3 discharges due to the freewheeling characteristic of the inductance. As shown in fig. 25, the current motor winding N3 is output near one end of the switching tube T5, and after being transmitted through the diode in the switching tube T5, the power battery 12 and the switch K5, flows back to one end of the motor winding N3 near the second power end. In this process, the first output voltage of the charging system 11 is the voltage of the motor winding N3. Obviously, the first output voltage is smaller than the power supply voltage, so the charging system 11 can perform step-down conversion on the power supply voltage.

Step two, boost conversion

As shown in fig. 22, the charging system 11 may further include a switch K4. The first end of the switch K4 is connected with the connecting ends of the N motor windings, and the second end of the switch K4 is connected with a first power supply end. During the step-up conversion, the MCU111 can turn on the first terminal and the second terminal a of the switch K5, turn on the switch K4 and turn off the switch K6, and the circuit status can be as shown in fig. 26. As can be seen from fig. 26, the circuit state in this case is equivalent to the charging system 11 shown in fig. 3, and therefore reference may be made to the step-up conversion process provided in the first embodiment, which is not repeated herein.

In addition, the charging system 11 shown in fig. 22 can also support voltage conversion in a buck-boost (buck-boost) mode for the power supply voltage. Specifically, the method comprises the following steps:

third, buck-boost

When buck-boost conversion is performed on the power supply voltage, the MCU111 may turn on the first terminal and the third terminal b of the switch K5 and turn on the switch K4, and the circuit state may be as shown in fig. 27. Based on the circuit state shown in fig. 27, the buck-boost conversion mainly includes the following two stages:

stage one: charging of the motor winding N3

The MCU111 turns on the switching tube T6 to charge the motor winding N3. As shown in fig. 28, the current is output from the positive electrode of the dc power supply, transmitted through the switching tube motor winding N3 and the switching tube T6, and then returned to the negative electrode of the dc power supply, thereby forming a charging loop of the motor winding N3.

And a second stage: discharge of motor winding N3

The MCU111 turns off the switching tube T5 to discharge the motor winding N3. As shown in fig. 29, the current is output from the end of the motor winding N3 close to the switch tube T5, and after being transmitted through the diode in the switch tube T5, the power battery 12 and the switch K5, the current flows back to the end of the motor winding N3 close to the first power supply end. It can be seen that the first output voltage of the charging system 11 is equal to the voltage of the motor winding N3. The MCU111 controls the voltage of the motor winding N3 by controlling the charging time of the motor winding N3 during phase one, thereby controlling the magnitude of the first output voltage, which may be either greater than or less than the supply voltage.

Similar to the embodiment, when the power voltage of the dc power source is within the charging voltage range of the power battery 12, the MCU111 may also turn on the first terminal and the second terminal a of the switch K5 and turn on the switch K6, so that the power battery 12 may directly receive the power voltage, thereby completing the charging. For specific implementation, reference may be made to the first embodiment, which is not described again.

EXAMPLE six

It should be noted that the charging system 11 shown in fig. 22 can also perform voltage step-down conversion on the battery voltage, and also perform voltage step-up conversion on the battery voltage, so that the battery voltages output by the high-voltage power battery and the low-voltage power battery can be adapted to the dc loads with different operating voltage ranges.

Next, with reference to fig. 22 as an example, the voltage up-conversion and the voltage down-conversion of the cell voltage will be described.

One, boost conversion

During the step-up conversion, the MCU111 may turn on the switch K6, and turn on the first terminal and the third terminal b of the switch K5, and the circuit state may be as shown in fig. 23. Based on the circuit state shown in fig. 23, taking bridge arm 3 including switching tube T5 and switching tube 6 as an example, the step-up conversion process mainly includes:

stage one: charging of the motor winding N3

The MCU111 turns on the switching tube T5 to charge the motor winding N3. As shown in fig. 30, the current is output from the positive electrode of the power battery 12, transmitted through the switching tube T5, the motor winding N3 and the switch K5, and then returned to the negative electrode of the power battery 12, thereby forming a charging circuit to charge the motor winding N3.

And a second stage: discharge of motor winding N3

The MCU111 turns off the switching tube T5 to discharge the motor winding N3. After the MCU111 turns off the switching tube T5, the charging loop is turned off. The motor winding N3 discharges due to the freewheeling characteristic of the inductance. As shown in fig. 31, the current is output from the positive electrode of the power battery 12, transmitted through the dc load, the diode in the switching tube T6, the motor winding N3, and the switching tube K5, and then returned to the negative electrode of the power battery 12. In this process, the second output voltage of the charging system 11 is the sum of the battery voltage of the power battery 12 and the voltage of the motor winding N3. Obviously, the second output voltage is greater than the battery voltage, so the charging system 11 can perform a step-up conversion on the battery voltage.

Step two, step-down conversion

As shown in fig. 22, the charging system 11 may further include a switch K4. The first end of the switch K4 is connected with the connection points of the N motor windings, and the second end of the switch K4 is connected with a first power supply end. During the step-down conversion process, the MCU111 may turn on the first terminal and the second terminal a of the switch K5, turn on the switch K4, and turn off the switch K6, and the circuit state may be as shown in fig. 26. As can be seen from fig. 26, the circuit state in this case is equivalent to the charging system 11 shown in fig. 3, and therefore reference may be made to the step-down conversion process provided in the second embodiment, which is not repeated herein.

In addition, the charging system 11 shown in fig. 22 can also support buck-boost mode voltage conversion on the battery voltage. Specifically, the method comprises the following steps:

third, buck-boost

When buck-boost conversion is performed on the battery voltage, the MCU111 may turn on the first terminal and the third terminal b of the switch K5 and turn on the switch K4, and the circuit state may be as shown in fig. 27. Based on the circuit state shown in fig. 27, the buck-boost conversion mainly includes the following two stages:

stage one: charging of the motor winding N3

The MCU111 turns on the switching tube T5 to charge the motor winding N3. As shown in fig. 32, the current is output from the positive electrode of the power battery 12, transmitted through the switching tube T5, the motor winding N3 and the switch K5, and then returned to the negative electrode of the power battery 12, thereby forming a charging loop of the motor winding N3.

And a second stage: discharge of motor winding N3

The MCU111 turns off the switching tube T5 to discharge the motor winding N3. As shown in fig. 33, the current is output from the end of the motor winding N3 near the first power supply terminal, and after passing through the dc load and the diode in the switch tube T6, the current flows back to the end of the motor winding N3 near the switch tube T6. It can be seen that the second output voltage of the charging system 11 is equal to the voltage of the motor winding N3. The MCU111 controls the voltage of the motor winding N3 by controlling the charging time of the motor winding N3 during phase one, thereby controlling the magnitude of the second output voltage, which may be either greater than or less than the battery voltage.

Similarly to the second embodiment, when the battery voltage of the power battery 12 is within the operating voltage range of the dc load, the MCU111 may also turn on the first terminal and the second terminal a of the switch K5 and turn on the switch K6, so that the power battery 12 can directly supply power to the dc load. For specific implementation, reference may be made to embodiment two, which is not described again.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present application without departing from the spirit and scope of the application. Thus, if such modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is intended to include such modifications and variations as well.

Claims

1. The charging system is characterized by comprising a motor controller MCU and a motor, wherein the MCU comprises N bridge arms, the motor comprises N motor windings, the N bridge arms and the N motor windings are respectively connected in a one-to-one correspondence manner, N is an integer greater than or equal to 1, and the motor controller MCU comprises:

the high-potential ends of the N bridge arms are connected with a first power supply end and a first battery end of the charging system, the first power supply end is used for connecting the anode of a direct-current power supply, the first battery end is used for connecting the anode of a power battery, the direct-current power supply is used for outputting power supply voltage, and the power battery is used for receiving first output voltage of the charging system;

the low-potential ends of the N bridge arms are connected with a second battery end of the charging system, and the second battery end is used for connecting the negative electrode of the power battery;

one end of each of the N motor windings is connected with the middle point of the corresponding bridge arm, the other end of each of the N motor windings is connected with a second power supply end of the charging system, and the second power supply end is used for connecting the negative electrode of the direct-current power supply;

the N bridge arms and the N motor windings form a voltage conversion circuit, and the MCU is used for:

and when the power supply voltage is smaller than the minimum charging voltage of the power battery, performing boost conversion on the power supply voltage through the voltage conversion circuit, and outputting the power supply voltage subjected to boost conversion to the power battery as the first output voltage, wherein the first output voltage is not smaller than the minimum charging voltage.

2. The charging system according to claim 1, wherein any one of the N bridge arms is a first bridge arm, the first bridge arm includes a first switching tube and a second switching tube, wherein a first electrode of the first switching tube is connected to the first battery terminal and the first power supply terminal, a second electrode of the first switching tube is connected to a first electrode of the second switching tube, and the intermediate point is located between the first switching tube and the second switching tube;

when the power supply voltage is less than the minimum charging voltage of the power battery, the MCU is specifically configured to:

the first switch tube is conducted so as to charge a first motor winding correspondingly connected with the first bridge arm;

and turning off the first switching tube to discharge the first motor winding.

3. The charging system according to claim 2, further comprising a first switch, a first terminal of the first switch being connected to the second battery terminal, a second terminal of the first switch being connected to the second power supply terminal;

the MCU is further configured to:

when the power supply voltage is within the charging voltage range of the power battery, the first switch is turned on;

and when the power supply voltage is out of the charging voltage range of the power battery, the first switch is turned off.

4. A charging system as claimed in claim 2 or 3, further comprising a first inductor having one end connected to the other end of the N motor windings, the other end of the first inductor being connected to the second power supply terminal.

5. The charging system of claim 1, wherein the MCU is further configured to:

when the power supply voltage is greater than the maximum charging voltage of the power battery, the voltage conversion circuit is used for carrying out voltage reduction conversion on the power supply voltage, the power supply voltage subjected to voltage reduction conversion is taken as the first output voltage to be output to the power battery, and the first output voltage is not greater than the maximum charging voltage.

6. The charging system according to claim 5, wherein any one of the N bridge arms is a first bridge arm, the first bridge arm comprises a first switching tube and a second switching tube, wherein a first electrode of the first switching tube is connected to the first battery terminal and the first power supply terminal, a second electrode of the first switching tube is connected to a first electrode of the second switching tube, and the intermediate point is located between the first switching tube and the second switching tube;

the charging system further comprises a first switch and a second switch, wherein the first end of the first switch is connected with the second battery end, the second end of the first switch is connected with the second power supply end, the first end of the second switch is connected with the first battery end, the second end of the second switch is connected with the other end of the N motor windings, and the third end of the second switch is connected with the first power supply end.

7. The charging system according to claim 6, wherein when the supply voltage is greater than a maximum charging voltage of the power battery, the MCU is specifically configured to:

turning on the first switch, and turning on a first end and a second end of the second switch;

the first switching tube is conducted so as to charge a first motor winding correspondingly connected with the first bridge arm;

and turning off the first switching tube to discharge the first motor winding.

8. The charging system according to claim 6 or 7, further comprising a third switch, a first end of the third switch being connected to the other end of the N motor windings, a second end of the third switch being connected to the second power supply terminal;

turning on a first terminal and a third terminal of the second switch, turning on the third switch, and turning off the first switch;

conducting the first switching tube to charge a first motor winding corresponding to the first bridge arm;

and turning off the first switching tube to discharge the first motor winding.

9. The charging system of claim 6, further comprising a third switch, a first end of the third switch being connected to the other end of the N motor windings, a second end of the third switch being connected to the second power supply terminal;

the MCU is specifically configured to:

turning on a first terminal and a second terminal of the second switch, and turning on the third switch;

and turning off the first switching tube to discharge the first motor winding.

10. The charging system of any one of claims 6, 7, and 9, wherein the MCU is further configured to:

and when the power supply voltage is within the charging voltage range of the power battery, conducting the first end and the third end of the second switch, and conducting the first switch.

11. The charging system is characterized by comprising a motor controller MCU and a motor, wherein the MCU comprises N bridge arms, the motor comprises N motor windings, the N bridge arms and the N motor windings are respectively connected in a one-to-one correspondence manner, N is an integer greater than or equal to 1, and the motor controller MCU comprises:

the high-potential ends of the N bridge arms are connected with a first power supply end and a first battery end of the charging system, the first power supply end is used for connecting the anode of a direct-current load, the first battery end is used for connecting the anode of a power battery, the direct-current load is used for receiving a second output voltage of the charging system, and the power battery is used for outputting a battery voltage to the charging system;

one end of each of the N motor windings is connected with the middle point of the corresponding bridge arm, the other end of each of the N motor windings is connected with a second power supply end of the charging system, and the second power supply end is used for connecting the negative electrode of the direct-current load;

when the battery voltage is greater than the maximum working voltage of the direct-current load, the voltage conversion circuit is used for carrying out voltage reduction conversion on the battery voltage, the battery voltage subjected to voltage reduction conversion is used as the second output voltage to be output to the direct-current load, and the second output voltage is not greater than the maximum working voltage.

12. The charging system according to claim 11, wherein any one of the N bridge arms is a first bridge arm, the first bridge arm includes a first switching tube and a second switching tube, wherein a first electrode of the first switching tube is connected to the first battery terminal and the first power supply terminal, a second electrode of the first switching tube is connected to a first electrode of the second switching tube, and the intermediate point is located between the first switching tube and the second switching tube;

when the battery voltage is greater than the maximum working voltage of the direct-current load, the MCU is specifically configured to:

the second switching tube is conducted so that a first motor winding correspondingly connected with the first bridge arm is charged;

and turning off the second switching tube to discharge the first motor winding.

13. The charging system according to claim 12, further comprising a first switch, a first terminal of the first switch being connected to the second battery terminal, a second terminal of the first switch being connected to the second power supply terminal;

the MCU is further configured to:

turning on the first switch when the battery voltage is within an operating voltage range of the DC load;

and when the battery voltage is out of the working voltage range of the direct current load, the first switch is turned off.

14. The charging system according to claim 12 or 13, further comprising a first inductor, one end of the first inductor being connected to the other end of the N motor windings, the other end of the first inductor being connected to the second power supply terminal.

15. The charging system of claim 11, wherein the MCU is further configured to:

and when the battery voltage is smaller than the minimum working voltage of the power battery, performing boost conversion on the battery voltage through the voltage conversion circuit, and outputting the battery voltage subjected to boost conversion to the direct current load as the second output voltage, wherein the second output voltage is not smaller than the minimum working voltage of the power battery.

16. The charging system according to claim 15, wherein any one of the N bridge arms is a first bridge arm, the first bridge arm includes a first switching tube and a second switching tube, wherein a first electrode of the first switching tube is connected to the first battery terminal and the first power supply terminal, a second electrode of the first switching tube is connected to a first electrode of the second switching tube, and the intermediate point is located between the first switching tube and the second switching tube;

17. The charging system of claim 16, wherein when the battery voltage is less than a minimum operating voltage of the dc load, the MCU is specifically configured to:

the second switching tube is conducted so as to charge a first motor winding correspondingly connected with the first bridge arm;

and turning off the second switching tube to discharge the first motor winding.

18. The charging system according to claim 16 or 17, further comprising a third switch, a first end of the third switch being connected to the other end of the N motor windings, a second end of the third switch being connected to the second power supply terminal;

the second switching tube is conducted so that a first motor winding corresponding to the first bridge arm can be charged;

and turning off the second switching tube to discharge the first motor winding.

19. The charging system of claim 16, further comprising a third switch, a first end of the third switch being connected to the other end of the N motor windings, a second end of the third switch being connected to the second power supply terminal;

the MCU is specifically configured to:

and turning off the second switching tube to discharge the first motor winding.

20. The charging system of any of claims 16, 17, and 19, wherein the MCU is further configured to:

and when the battery voltage is within the working voltage range of the direct current load, conducting the first end and the third end of the second switch, and conducting the first switch.

21. The charging system is characterized by comprising a motor controller MCU and a motor, wherein the MCU comprises N bridge arms, the motor comprises N motor windings, the N bridge arms and the N motor windings are respectively connected in a one-to-one correspondence manner, N is an integer greater than or equal to 1, and the motor controller MCU comprises:

the high-potential ends of the N bridge arms are connected with a first battery end of the charging system, the first battery end is used for being connected with a positive electrode of a power battery, and the power battery is used for receiving a first output voltage of the charging system;

the low-potential ends of the N bridge arms are connected with a second battery end and a second power supply end of the charging system, the second battery end is used for connecting the negative electrode of the power battery, the second power supply end is used for connecting the negative electrode of a direct-current power supply, and the direct-current power supply is used for outputting power supply voltage;

one end of each of the N motor windings is connected with the middle point of the corresponding bridge arm, the other end of each of the N motor windings is connected with a first power supply end of the charging system, and the first power supply end is used for connecting the positive electrode of the direct-current power supply;

when the power supply voltage is smaller than the minimum charging voltage of the power battery, performing boost conversion on the power supply voltage through the voltage conversion circuit, and outputting the power supply voltage subjected to boost conversion to the power battery as a first output voltage, wherein the first output voltage is not smaller than the minimum charging voltage;

22. The charging system according to claim 21, wherein any one of the N bridge arms is a first bridge arm, the first bridge arm comprises a first switching tube and a second switching tube, wherein a first electrode of the first switching tube is connected to the first battery terminal and the first power supply terminal, a second electrode of the first switching tube is connected to a first electrode of the second switching tube, and the intermediate point is located between the first switching tube and the second switching tube;

the charging system further comprises a sixth switch and a fifth switch, wherein a first end of the fifth switch is connected with the second battery end, a second end of the fifth switch is connected with the low-potential ends of the N bridge arms, a third end of the fifth switch is connected with the other ends of the N motor windings, a first end of the sixth switch is connected with the first battery end, and a second end of the sixth switch is connected with the first power supply end.

23. The charging system according to claim 22, wherein when the supply voltage is greater than a maximum charging voltage of the power battery, the MCU is specifically configured to:

the sixth switch is conducted, and the first end and the third end of the fifth switch are conducted;

and turning off the second switching tube to discharge the first motor winding.

24. The charging system according to claim 22 or 23, further comprising a fourth switch, a first terminal of the fourth switch being connected to the other terminal of the N motor windings, a second terminal of the fourth switch being connected to the first power supply terminal;

turning on a first end and a second end of the fifth switch, turning on the fourth switch, and turning off the sixth switch;

and turning off the second switching tube to discharge the first motor winding.

25. The charging system of claim 22, further comprising a fourth switch, a first terminal of the fourth switch being connected to the other terminal of the N motor windings, a second terminal of the fourth switch being connected to the first power supply terminal;

the MCU is specifically configured to:

conducting the first terminal and the third terminal of the fifth switch, and conducting the fourth switch;

and turning off the second switching tube to discharge the first motor winding.

26. The charging system of any of claims 22, 23, and 25, wherein the MCU is further configured to:

and when the power supply voltage is within the charging voltage range of the power battery, conducting the first end and the second end of the fifth switch, and conducting the sixth switch.

27. The charging system is characterized by comprising a motor controller MCU and a motor, wherein the MCU comprises N bridge arms, the motor comprises N motor windings, the N bridge arms and the N motor windings are respectively connected in a one-to-one correspondence manner, N is an integer greater than or equal to 1, and the motor controller MCU comprises:

the high-potential ends of the N bridge arms are connected with a first battery end of the charging system, the first battery end is used for being connected with a positive electrode of a power battery, and the power battery is used for outputting battery voltage to the charging system;

the low-potential ends of the N bridge arms are connected with a second battery end and a second power supply end of the charging system, the second battery end is used for being connected with the negative electrode of the power battery, the second power supply end is used for being connected with the negative electrode of a direct-current load, and the direct-current load is used for receiving a second output voltage of the charging system;

one end of each of the N motor windings is connected with the middle point of the corresponding bridge arm, the other end of each of the N motor windings is connected with a first power supply end of the charging system, and the first power supply end is used for connecting the positive electrode of the direct-current load;

when the battery voltage is greater than the maximum working voltage of the direct-current load, performing voltage reduction conversion on the battery voltage through the voltage conversion circuit, and outputting the battery voltage subjected to voltage reduction conversion to the direct-current load as a second output voltage, wherein the second output voltage is not greater than the maximum working voltage of the direct-current load;

and when the battery voltage is smaller than the minimum working voltage of the direct-current load, performing boost conversion on the battery voltage through the voltage conversion circuit, and outputting the battery voltage subjected to boost conversion to the direct-current load as the second output voltage, wherein the second output voltage is not smaller than the minimum working voltage of the direct-current load.

28. The charging system according to claim 27, wherein any one of the N bridge arms is a first bridge arm, the first bridge arm comprises a first switching tube and a second switching tube, wherein a first electrode of the first switching tube is connected to the first battery terminal and the first power supply terminal, a second electrode of the first switching tube is connected to a first electrode of the second switching tube, and the intermediate point is located between the first switching tube and the second switching tube;

29. The charging system of claim 28, wherein when the battery voltage is less than a minimum operating voltage of the dc load, the MCU is specifically configured to:

and turning off the first switching tube to discharge the first motor winding.

30. The charging system according to claim 28 or 29, further comprising a fourth switch, a first terminal of the fourth switch being connected to the other terminal of the N motor windings, a second terminal of the fourth switch being connected to the first power supply terminal;

and turning off the first switching tube to discharge the first motor winding.

31. The charging system of claim 28, further comprising a fourth switch, a first terminal of the fourth switch being connected to the other terminal of the N motor windings, a second terminal of the fourth switch being connected to the first power supply terminal;

the MCU is specifically configured to:

conducting the first terminal and the third terminal of the fifth switch, and conducting the sixth switch;

and turning off the first switching tube to discharge the first motor winding.

32. The charging system of any of claims 28, 29, and 31, wherein the MCU is further configured to:

and when the battery voltage is within the working voltage range of the direct current load, conducting the first end and the second end of the fifth switch, and conducting the sixth switch.

33. An electric vehicle comprising a power battery and a charging system according to any one of claims 1 to 32 for charging the power battery.