CN118269675A

CN118269675A - Pre-charging system of high-voltage loop capacitor, pre-charging control method and vehicle

Info

Publication number: CN118269675A
Application number: CN202410385233.1A
Authority: CN
Inventors: 杨晖; 李维诚; 郝永健; 刘琪; 石雷
Original assignee: BYD Co Ltd
Current assignee: BYD Co Ltd
Priority date: 2024-03-28
Filing date: 2024-03-28
Publication date: 2024-07-02

Abstract

The present disclosure relates to a pre-charge system of a high-voltage loop capacitor, a pre-charge control method, and a vehicle. The priming system includes: the power battery, the main positive contactor, the main negative contactor, the DC-DC module and the load energy storage capacitor; the first end of the main positive contactor is connected with the positive electrode of the power battery and the first end of the DC-DC module, and the second end of the main positive contactor is connected with the second end of the DC-DC module and the first end of the load energy storage capacitor; the first end of the main negative contactor is connected with the negative electrode of the power battery and the third end of the DC-DC module, the second end of the main negative contactor is connected with the fourth end of the DC-DC module and the second end of the load energy storage capacitor, and the DC-DC module is used for performing voltage conversion on direct current provided by the power battery, and providing the converted direct current for the load energy storage capacitor to realize high-voltage precharge. Therefore, the heat energy generated in the pre-charging process can be reduced, and the energy transfer efficiency and the charging speed can be improved.

Description

Pre-charging system of high-voltage loop capacitor, pre-charging control method and vehicle

Technical Field

The disclosure relates to the field of circuit control, in particular to a high-voltage loop capacitor pre-charging system, a pre-charging control method and a vehicle.

Background

The new energy automobile is powered by the power battery and outputs power to the load, and a load energy storage capacitor is arranged at the input side of part of the load. At the moment of high voltage on the automobile, if the main positive contactor and the main negative contactor of the main loop of the power battery are directly closed, larger impact current can be generated due to the influence of the load side energy storage capacitor, and the main positive contactor and the main negative contactor can be possibly adhered. To avoid damaging the main positive and main negative contactors by the impact current, a pre-charge circuit is added to the main circuit.

The conventional pre-charge circuit includes a pre-charge contactor and a pre-charge resistor. However, the larger current flowing through the precharge resistor during the precharge process generates larger heat, so that the energy transfer efficiency is lower; in addition, the charging speed of the pre-charging loop is limited by the pre-charging resistance value, and the charging speed is low.

Disclosure of Invention

The disclosure aims to provide a pre-charging system of a high-voltage loop capacitor, a pre-charging control method and a vehicle, so as to reduce heat energy generated in a pre-charging process and improve energy transfer efficiency and charging speed.

In order to achieve the above object, a first aspect of the present disclosure provides a pre-charging system for a high voltage loop capacitor, including a power battery, a main positive contactor, a main negative contactor, a DC-DC module, and a load energy storage capacitor;

The first end of the main positive contactor is connected with the positive electrode of the power battery and the first end of the DC-DC module, and the second end of the main positive contactor is connected with the second end of the DC-DC module and the first end of the load energy storage capacitor; the first end of the main negative contactor is connected with the negative electrode of the power battery and the third end of the DC-DC module, the second end of the main negative contactor is connected with the fourth end of the DC-DC module and the second end of the load energy storage capacitor, wherein,

The DC-DC module is used for carrying out voltage conversion on direct current provided by the power battery, and providing the converted direct current for the load energy storage capacitor to realize high-voltage pre-charging.

Optionally, the DC-DC module is an isolated DC-DC converter.

Optionally, the DC-DC module includes a DC-DC controller for controlling the output voltage of the DC-DC module to gradually increase until the output voltage reaches a target voltage in response to determining that the main negative contactor is closed.

Optionally, the DC-DC module includes a primary side circuit and a secondary side circuit;

The primary side circuit is connected with the power battery, and the secondary side circuit is connected with the load energy storage capacitor.

Optionally, the primary side circuit includes a primary side branch;

The primary side branch comprises a primary side winding of a transformer and a full-control switching device; the positive electrode of the power battery is connected with the homonymous end of the primary winding, and the negative electrode of the power battery is connected with the heteronymous end of the primary winding through the fully-controlled switching device;

the DC-DC controller is connected with the full-control switching device and is used for controlling the duty ratio of the full-control switching device to gradually increase the output voltage of the DC-DC module in response to determining that the main negative contactor is closed.

Optionally, the DC-DC controller is further configured to adjust the duty ratio of the fully controlled switching device if the output voltage of the DC-DC module is different from a preset voltage corresponding to the current time.

Optionally, the secondary side circuit includes a first secondary winding of a transformer, a first diode, a second diode, and an inductance; the same-name end of the first secondary winding is connected with the anode of the first diode, the cathode of the first diode is connected with the first end of the load energy storage capacitor through the inductor, the cathode of the first diode is also connected with the cathode of the second diode, and the anode of the second diode is connected with the different-name end of the first secondary winding and the second end of the load energy storage capacitor;

Wherein the inductor and the load storage capacitor are configured to be charged by electrical energy provided by the first secondary winding when the fully controlled switching device is closed; the load energy storage capacitor is also used for being charged by the electric energy provided by the inductor when the fully-controlled switching device is turned off;

The primary side circuit further comprises a magnetic reset branch circuit, wherein the magnetic reset branch circuit is used for demagnetizing a magnetic core of the transformer when the fully-controlled switching device is turned off.

Optionally, the magnetic reset branch includes a second secondary winding of the transformer and a third diode;

the positive electrode of the power battery is connected with the synonym end of the second secondary winding, the negative electrode of the power battery is connected with the anode of the third diode, and the cathode of the third diode is connected with the synonym end of the second secondary winding.

Optionally, the secondary side circuit includes a third secondary winding and a fourth diode of the transformer; the homonymous end of the third secondary winding is connected with the second end of the energy storage capacitor; the synonym end of the third secondary winding is connected with the anode of the fourth diode, and the cathode of the fourth diode is connected with the first end of the energy storage capacitor;

The load energy storage capacitor is used for being charged by electric energy provided by the third secondary winding when the fully-controlled switching device is turned off; the primary winding is used for storing energy when the fully-controlled switching device is closed.

Optionally, the priming system further comprises a contactor controller;

the contactor controller is connected with the main negative contactor and is used for controlling the main negative contactor to be closed in response to receiving a high-voltage power-on instruction.

Optionally, the priming system further comprises a contactor controller;

the contactor controller is coupled to the main positive contactor for controlling the main positive contactor to close in response to determining that the high voltage precharge is complete.

A second aspect of the present disclosure provides a method for controlling a pre-charge of a high-voltage loop capacitor, which is applied to a pre-charge system of a high-voltage loop capacitor provided in the first aspect of the present disclosure, the method comprising:

the DC-DC module performs voltage conversion on direct current provided by the power battery, and provides the converted direct current for the load energy storage capacitor to realize high-voltage pre-charging.

Optionally, the pre-charging system of the high-voltage loop capacitor further includes a contactor controller, and the pre-charging control method further includes:

In response to receiving a high voltage power-on command, the contact controller controls the primary negative contactor to close.

in response to determining that high voltage precharge is complete, the contact controller controls the main positive contactor to close.

A third aspect of the present disclosure provides a vehicle comprising the pre-charge system of the high voltage loop capacitor provided by the first aspect of the present disclosure.

In the technical scheme, the high-voltage pre-charge is realized by using the DC-DC module by designing a new circuit topology of the power battery, the main positive contactor, the main negative contactor, the DC-DC module and the load energy storage capacitor. Compared with the high-voltage pre-charging realized through the pre-charging contactor and the pre-charging resistor in the related art, the high-voltage pre-charging realized through the DC-DC module can reduce the heat energy generated in the pre-charging process, improve the energy transfer efficiency and the charging speed, and the DC-DC module occupies smaller volume, thereby being beneficial to reducing the volume of a high-voltage system of a vehicle.

Additional features and advantages of the present disclosure will be set forth in the detailed description which follows.

Drawings

The accompanying drawings are included to provide a further understanding of the disclosure, and are incorporated in and constitute a part of this specification, illustrate the disclosure and together with the description serve to explain, but do not limit the disclosure. In the drawings:

fig. 1 is a schematic diagram of a structure of a high-voltage loop capacitor pre-charging system in the related art.

Fig. 2 is a block diagram of a pre-charge system for a high voltage loop capacitor provided by an embodiment of the present disclosure.

Fig. 3 is a schematic structural diagram of a high voltage loop capacitor pre-charging system according to an embodiment of the present disclosure.

Fig. 4 is a schematic structural diagram of a high voltage loop capacitor pre-charging system according to an embodiment of the present disclosure.

Fig. 5 is a flowchart of a method for controlling the pre-charge of a high voltage loop capacitor provided by an embodiment of the present disclosure.

Fig. 6 is a flowchart of a method for controlling the pre-charge of a high voltage loop capacitor provided by an embodiment of the present disclosure.

Detailed Description

Specific embodiments of the present disclosure are described in detail below with reference to the accompanying drawings. It should be understood that the detailed description and specific examples, while indicating and illustrating the disclosure, are not intended to limit the disclosure.

In the following description, the words "first," "second," and the like are used merely for distinguishing between the descriptions and not for indicating or implying a relative importance or order.

First, an application scenario of the present disclosure will be described. The pre-charging system is applied to a plurality of high-voltage direct-current battery systems (such as a power battery system of an electric vehicle) and is used for avoiding large current impact in the high-voltage power-on process and protecting components in a circuit. Fig. 1 is a schematic structural diagram of a high-voltage loop capacitor pre-charging system in the related art, and as shown in fig. 1, the pre-charging system includes a power battery 101, a main positive contactor 102, a main negative contactor 103, a pre-charging contactor 201, a pre-charging resistor 202, and a load storage capacitor 105. The first ends (left side end in the plane direction of fig. 1) of the main positive contactor 102 and the precharge contactor 201 are connected to the positive electrode of the power battery 101; a first end (left end in the plane direction of fig. 1) of the main negative contactor 103 is connected to the negative electrode of the power battery 101; the second end (right side end in the plane direction of fig. 1) of the main positive contactor 102 is connected to the first end (upper side end in the plane direction of fig. 1) of the load storage capacitor 105, the second end (right side end in the plane direction of fig. 1) of the precharge contactor 201 is connected to the first end of the load storage capacitor 105 through the precharge resistor 202, and the second end (right side end in the plane direction of fig. 1) of the main negative contactor 103 is connected to the second end (lower side end in the plane direction of fig. 1) of the load storage capacitor 105.

The load energy storage capacitor 105 is connected with high-voltage electric equipment, and the load energy storage capacitor 105 can be used for maintaining the stability of the voltage of the high-voltage electric equipment of the vehicle after being fully charged so as to protect the high-voltage electric equipment. When the vehicle is powered up at high voltage, if the high voltage dc of the power battery 101 is directly connected to the load energy storage capacitor 105, since the voltage of the load energy storage capacitor 105 is close to 0, a great current surge is generated at this time, and the main positive contactor 102 and the main negative contactor 103 of the vehicle are damaged. Therefore, when the vehicle is powered on at high voltage, the load energy storage capacitor 105 needs to be precharged at high voltage, the main positive contactor 102 is opened, the main negative contactor 103 and the precharge contactor 201 are closed, so that the high-voltage direct current of the power battery 101 slowly charges the load energy storage capacitor 105 through the precharge resistor 202 due to the effect of the precharge resistor 202, and when the voltage of the load energy storage capacitor 105 reaches or approaches to the voltage of the power battery 101, the main positive contactor 102 is closed, the precharge contactor 201 is opened, and the power battery 101 directly supplies power to the load energy storage capacitor 105. Therefore, high-current impact generated in the high-voltage power-on process can be avoided, components in the circuit are protected, and the safety of the high-voltage power-on is ensured. However, in the related art, the current flowing through the pre-charging resistor 202 during the pre-charging process is large, and a large amount of heat is generated, so that the energy transfer efficiency is low; in addition, the charging speed of the pre-charging loop is limited by the resistance value of the pre-charging resistor 202, and the charging speed is slow.

To solve the above-mentioned problems, the present disclosure provides a pre-charging system for a high-voltage loop capacitor. Fig. 2 is a block diagram of a pre-charge system for a high voltage loop capacitor provided by an embodiment of the present disclosure. As shown in fig. 2, the pre-charge system includes a power cell 101, a main positive contactor 102, a main negative contactor 103, a DC-DC module 104, and a load storage capacitor 105.

The first end of the main positive contactor 102 is connected with the positive electrode of the power battery 101 and the first end of the DC-DC module 104, the second end of the main positive contactor 102 is connected with the second end of the DC-DC module 104 and the first end of the load energy storage capacitor 105; the first end of the main negative contactor 103 is connected with the negative electrode of the power battery 101 and the third end of the DC-DC module 104, the second end of the main negative contactor 103 is connected with the fourth end of the DC-DC module 104 and the second end of the load energy storage capacitor 105;

The DC-DC module 104 is configured to perform voltage conversion on the direct current provided by the power battery 101, and provide the converted direct current to the load energy storage capacitor 105, so as to implement high-voltage precharge.

In the planar direction of fig. 2, the positive electrode of the power cell 101 is the upper side end, and the negative electrode of the power cell 101 is the lower side end; the first end of the main positive contactor 102 and the first end of the main negative contactor 103 are left side ends, and the second end of the main positive contactor 102 and the second end of the main negative contactor 103 are right side ends; the first end of the DC-DC module 104 is the upper left end, the second end of the DC-DC module 104 is the upper right end, the third end of the DC-DC module 104 is the lower left end, and the fourth end of the DC-DC module 104 is the lower right end; the first end of the load storage capacitor 105 is an upper end, and the second end of the load storage capacitor 105 is a lower end.

In one embodiment, the DC-DC module 104 may be an isolated DC-DC converter. The DC-DC module 104 can realize functions of voltage transformation ratio, electrical isolation, energy transmission and the like, and the DC-DC module 104 has strong noise immunity, high energy conversion efficiency, small volume, light weight and isolation. Therefore, the DC-DC module 104 replaces the precharge contactor 201 and the precharge resistor 202 in the related art to realize high-voltage precharge, so that on one hand, the heat energy generated in the precharge process can be reduced, the energy transfer efficiency is improved, and the charging speed is improved; on the other hand, the DC-DC module 104 typically occupies a smaller volume than the pre-charge contactor 201 and the pre-charge resistor 202, which is advantageous for reducing the volume of the vehicle high voltage system. Furthermore, the cost of the DC-DC module 104 is typically lower than that of the pre-charge resistor 202, and therefore, implementing high voltage pre-charge with the DC-DC module 104 may also effectively reduce the cost of the vehicle high voltage system.

In the above technical solution, the high voltage pre-charge is implemented by the DC-DC module 104 by designing a new circuit topology of the power battery 101, the main positive contactor 102, the main negative contactor 103, the DC-DC module 104 and the load storage capacitor 105. Compared with the high-voltage pre-charging realized by the pre-charging contactor 201 and the pre-charging resistor 202 in the related art, the high-voltage pre-charging realized by the DC-DC module 104 can reduce the heat energy generated in the pre-charging process, improve the energy transfer efficiency and the charging speed, and the volume occupied by the DC-DC module 104 is smaller, thereby being beneficial to reducing the volume of a high-voltage system of a vehicle.

In an alternative embodiment, the DC-DC module 104 includes a DC-DC controller 1041, the DC-DC controller 1041 being configured to control the output voltage of the DC-DC module 104 to gradually increase until the output voltage reaches the target voltage in response to determining that the primary negative contactor 103 is closed.

For example, if it is determined that the main negative contactor 103 is closed, it may be determined to begin high voltage pre-charging the load storage capacitor 105. The output voltage of the DC-DC module 104 is the voltage difference between the second and fourth terminals of the DC-DC module 104. The target voltage may be preset based on actual demand, and may be set to a voltage value (e.g., 600 v) of the power battery 101, for example. For example, the DC-DC controller 1041 may gradually increase the output voltage by a preset step size every preset time period, where the preset step size may be 20v, and the DC-DC module 104 is controlled to increase the output voltage by 20v on the previous basis every time the operation duration of the DC-DC module reaches the preset time period; for another example, the DC-DC controller 1041 may gradually increase the output voltage according to a preset time period and a preset step voltage value, which gradually increases from small to large, such as 50v,100v,300v, and 600v. In this way, the DC-DC module 104 can realize safe pre-charging by controlling the output voltage to gradually increase, and avoid the impact of large current caused by direct high-voltage power-up.

In an alternative embodiment, DC-DC module 104 includes primary side circuitry and secondary side circuitry; the primary side circuit is connected to the power battery 101, and the secondary side circuit is connected to the load storage capacitor 105.

In an alternative embodiment, the primary side circuit includes a primary side leg;

The primary side branch comprises a primary side winding N1 of a transformer 1042 and a fully controlled switching device 1043; the positive electrode of the power battery 101 is connected with the homonymous end of the primary winding N1, and the negative electrode of the power battery 101 is connected with the heteronymous end of the primary winding N1 through a fully-controlled switching device 1043;

The DC-DC controller 1041 is connected to the fully controlled switching device 1043 for controlling a duty cycle of the fully controlled switching device 1043 to gradually increase the output voltage of the DC-DC module 104 in response to determining that the main negative contactor 103 is closed.

Illustratively, the dots in fig. 3 and 4 are used to indicate the same name ends of windings in the transformer 1042, and the other ends of windings without dots are different name ends. The fully controlled switching device 1043 may be any one of a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) or an IGBT (insulated gate bipolar transistor, insulate-Gate Bipolar Transistor). The fully-controlled switching device 1043 is connected to the DC-DC controller 1041, and the DC-DC controller 1041 can control the duty ratio of the fully-controlled switching device 1043 by a pulse width modulation (PWM, pulse Width Modulation) method, so as to control the output voltage of the DC-DC module 104.

Optionally, the DC-DC controller 1041 is further configured to adjust the duty cycle of the fully-controlled switching device 1043 if the output voltage of the DC-DC module 104 is different from the preset voltage corresponding to the current time.

For example, a voltage sampling point may be provided at the output of the DC-DC module 104 to collect the output voltage of the DC-DC module 104. The output voltage of the DC-DC module 104 gradually rises during the precharge process, and corresponds to different preset voltages at different times throughout the process. However, during the actual charging process, it may be difficult to make the output voltage of the DC-DC module 104 coincide with the preset voltage corresponding to the current time even if the fully-controlled switching device 1043 is controlled at the preset duty ratio because of being disturbed by various factors such as external noise. At this time, the output voltage of the DC-DC module 104 may reach the preset voltage corresponding to the current time by adjusting the duty ratio. For example, if the output voltage of the DC-DC module 104 is smaller than the preset voltage corresponding to the current time, the duty cycle of the fully-controlled switching device 1043 may be controlled to increase; if the output voltage of the DC-DC module 104 is greater than the preset voltage corresponding to the current time, the duty cycle of the fully-controlled switching device 1043 may be controlled to decrease. In this manner, accuracy of the output voltage control of the DC-DC module 104 may be improved.

In an alternative embodiment, as shown in fig. 3, the secondary side circuit includes a first secondary winding N2 of a transformer 1042, a first diode D1, a second diode D2, and an inductance L1; the homonymous end of the first secondary winding N2 is connected with the anode of a first diode D1, the cathode of the first diode D1 is connected with the first end of a load energy storage capacitor 105 through an inductor L1, the cathode of the first diode D1 is also connected with the cathode of a second diode D2, and the anode of the second diode D2 is connected with the heteronymous end of the first secondary winding N2 and the second end of the load energy storage capacitor 105;

Wherein the inductor L1 and the load storage capacitor 105 are used to charge by the electrical energy provided by the first secondary winding N2 when the fully controlled switching device 1043 is closed; the load storage capacitor 105 is further used for charging by the electric energy provided by the inductor L1 when the fully controlled switching device 1043 is turned off;

The primary side circuit further includes a magnetic reset branch for demagnetizing the core of the transformer 1042 when the fully controlled switching device 1043 is turned off.

Wherein the magnetic reset branch may include a second secondary winding N3 of the transformer 1042 and a third diode D3; the positive electrode of the power battery 101 is connected with the synonym end of the second secondary winding N3, the negative electrode of the power battery 101 is connected with the anode of the third diode D3, and the cathode of the third diode D3 is connected with the synonym end of the second secondary winding N3.

Illustratively, in the DC-DC module 104 of the pre-charge system shown in fig. 3, the transformer 1042 includes three parts of a primary winding N1, a first secondary winding N2 and a second secondary winding N3, which are wound on the same core, i.e. an increase in the voltage of any one of the three windings may cause an increase in the magnetic flux of the core or even saturation. When the fully controlled switching device 1043 is turned on, the voltage of the primary winding N1 is positive and negative, the voltage of the first secondary winding N2 is also positive and negative, and the voltage of the second secondary winding N3 is positive and negative, because of the single-phase conductivity of the third diode D3, the second secondary winding N3 has no current, and at this time, the power battery 101 releases energy to the first secondary winding N2 of the transformer 1042 through the primary winding N1 of the transformer 1042, and the first secondary winding N2 charges the inductor L1 and the load storage capacitor 105 through the first diode D1. When the fully-controlled switching device 1043 is turned off, the polarities of the voltages of the windings are reversed, the second secondary winding N3 forms a loop with the third diode D3 through the power supply, and the energy of the primary winding N1 of the transformer 1042 is transferred to the power battery 101 through the second secondary winding N3 to demagnetize the magnetic core; at the same time, the inductor L1 freewheels through the second diode D2 to charge the load storage capacitor 105, so as to maintain the output voltage of the DC-DC module 104 constant.

In an alternative embodiment, as shown in fig. 4, the secondary side circuit includes a third secondary winding N4 of a transformer 1042 and a fourth diode D4; the homonymous end of the third secondary winding N4 is connected with the second end of the energy storage capacitor; the synonym end of the third secondary winding N4 is connected with the anode of a fourth diode D4, and the cathode of the fourth diode D4 is connected with the first end of the energy storage capacitor;

Wherein the load storage capacitor 105 is used for charging by the electric energy provided by the third secondary winding N4 when the fully-controlled switching device 1043 is turned off; the primary winding N1 is used to store energy when the fully controlled switching device 1043 is closed.

Illustratively, in the DC-DC module 104 of the pre-charge system shown in fig. 4, the transformer 1042 comprises two parts, a primary winding N1 and a third secondary winding N4, which are wound on the same core. When the fully-controlled switching device 1043 is turned on, the voltage of the primary winding N1 is positive and negative, and the voltage of the third secondary winding N4 is positive and negative, the power battery 101, the primary winding N1 and the fully-controlled switching device 1043 form a loop, and at this time, the power battery 101 stores energy into the primary winding N1 of the transformer 1042, and no current flows in the third secondary winding N4 due to the single-phase conductivity of the fourth diode D4. When the fully controlled switching device 1043 is turned off, the polarities of the voltages of the windings are reversed, and the energy stored in the primary winding N1 is transferred to the third secondary winding N4, and freewheels through the fourth diode D4 to charge the load storage capacitor 105.

It should be noted that the diode in the present disclosure may be replaced by other electronic components having single-phase conductive properties. The circuit structure in the DC-DC module 104 shown in fig. 3 and fig. 4 is used as an illustration, and the isolated DC-DC converter with other structures can also replace the pre-charging resistor 202 and the pre-charging contactor 201 in the related art to realize the function of high-voltage pre-charging.

In an alternative embodiment, the priming system further comprises a contactor controller;

The contactor controller is connected to the main negative contactor 103 for controlling the main negative contactor 103 to close in response to receiving a high voltage power-on command.

the contactor controller is in communication with the main positive contactor 102 for controlling the main positive contactor 102 to close in response to determining that the high voltage precharge is complete.

For example, if the voltage of the load storage capacitor 105 reaches the target voltage, it may be determined that the high voltage precharge is completed. To further ensure stability of the voltage of the load storage capacitor 105, the high voltage precharge may be determined to be complete when the duration of the voltage of the load storage capacitor 105 reaching the target voltage reaches a preset duration. In the pre-charging system provided by the disclosure, after the main negative contactor 103 is closed, the DC-DC module 104 starts to perform high-voltage pre-charging on the load energy storage capacitor 105, so that the output voltage of the DC-DC module 104 gradually rises from 0v to the target voltage, and the load energy storage capacitor 105 is gradually charged; when the high-voltage pre-charging is determined to be completed, the main positive contactor 102 is controlled to be closed, and at the moment, the power battery 101 directly supplies power to the load energy storage capacitor 105, so that high-current impact generated in the high-voltage power-on process can be avoided, components in the circuit are protected, and the safety of the high-voltage power-on is ensured.

Based on the same inventive concept, the disclosure also provides a pre-charge control method of the high-voltage loop capacitor. Fig. 5 is a flowchart of a method for controlling the pre-charging of a high-voltage loop capacitor according to an embodiment of the present disclosure, which is applied to a pre-charging system of a high-voltage loop capacitor as shown in the previous embodiment. As shown in fig. 5, the method includes step S501.

S501, the DC-DC module performs voltage conversion on direct current provided by the power battery, and provides the converted direct current for the load energy storage capacitor to realize high-voltage pre-charging.

Therefore, compared with the high-voltage pre-charging realized through the pre-charging contactor and the pre-charging resistor in the related art, the high-voltage pre-charging realized through the DC-DC module can reduce the heat energy generated in the pre-charging process, improve the energy transfer efficiency and the charging speed, and the DC-DC module occupies smaller volume, thereby being beneficial to reducing the volume of a high-voltage system of a vehicle. By pre-charging the load energy storage capacitor, high current impact generated in the high-voltage power-on process can be avoided, components in the circuit are protected, and the safety of the high-voltage power-on is ensured.

In an alternative embodiment, the present disclosure provides for the priming system to further include a contactor controller. As shown in fig. 6, the precharge control side includes S502, S501, and S503.

S502, in response to receiving a high-voltage power-on instruction, the contact controller controls the main negative contactor to be closed.

S503, in response to determining that the high voltage precharge is completed, the contact controller controls the main positive contactor to be closed.

Therefore, high-current impact generated in the high-voltage power-on process can be avoided, components in the circuit are protected, and the safety of the high-voltage power-on is ensured.

Optionally, in S501, the DC-DC module includes a DC-DC controller, and the DC-DC module performs voltage conversion on direct current provided by the power battery, and provides the converted direct current to the load energy storage capacitor to implement high voltage pre-charging, including:

In response to determining that the primary negative contactor is closed, the DC-DC controller controls the output voltage of the DC-DC module to gradually increase until the output voltage reaches a target voltage.

Optionally, if the DC-DC controller is connected to the fully controlled switching device, the DC-DC controller is configured to control the output voltage of the DC-DC module to gradually increase by:

in response to determining that the primary negative contactor is closed, the duty cycle of the fully controlled switching device is controlled to gradually increase the output voltage of the DC-DC module.

Optionally, if the DC-DC controller is connected to the fully controlled switching device, the precharge controller provided in the present disclosure may further include:

and if the output voltage of the DC-DC module is different from the preset voltage corresponding to the current moment, the DC-DC controller adjusts the duty ratio of the fully-controlled switching device.

The specific manner in which the steps of the method of the above embodiments are described in detail in relation to the embodiments of the system will not be explained in detail here.

The disclosure also provides a vehicle, including the above-mentioned high-voltage loop capacitor's of the disclosure prefill system.

The preferred embodiments of the present disclosure have been described in detail above with reference to the accompanying drawings, but the present disclosure is not limited to the specific details of the embodiments described above, and various simple modifications may be made to the technical solutions of the present disclosure within the scope of the technical concept of the present disclosure, and all the simple modifications belong to the protection scope of the present disclosure.

In addition, the specific features described in the above embodiments may be combined in any suitable manner without contradiction. The various possible combinations are not described further in this disclosure in order to avoid unnecessary repetition.

Moreover, any combination between the various embodiments of the present disclosure is possible as long as it does not depart from the spirit of the present disclosure, which should also be construed as the disclosure of the present disclosure.

Claims

1. The pre-charging system of the high-voltage loop capacitor is characterized by comprising a power battery, a main positive contactor, a main negative contactor, a DC-DC module and a load energy storage capacitor;

2. The priming system of claim 1, wherein the DC-DC module is an isolated DC-DC converter.

3. The priming system of claim 1, wherein said DC-DC module comprises a DC-DC controller for controlling an output voltage of said DC-DC module to gradually increase until said output voltage reaches a target voltage in response to determining that said main negative contactor is closed.

4. A priming system according to claim 3, wherein said DC-DC module comprises a primary side circuit and a secondary side circuit;

5. The priming system of claim 4, wherein said primary side circuit comprises a primary side leg;

6. The priming system of claim 5, wherein the DC-DC controller is further configured to adjust a duty cycle of the fully controlled switching device if an output voltage of the DC-DC module is different from a preset voltage corresponding to a current time.

7. The priming system of claim 5, wherein the priming system further comprises a priming system for priming the priming system,

The secondary side circuit comprises a first secondary winding of the transformer, a first diode, a second diode and an inductor; the same-name end of the first secondary winding is connected with the anode of the first diode, the cathode of the first diode is connected with the first end of the load energy storage capacitor through the inductor, the cathode of the first diode is also connected with the cathode of the second diode, and the anode of the second diode is connected with the different-name end of the first secondary winding and the second end of the load energy storage capacitor;

8. The priming system of claim 7, wherein said magnetic reset leg comprises a second secondary winding of said transformer and a third diode;

9. The priming system of claim 5, wherein the priming system further comprises a priming system for priming the priming system,

The secondary side circuit comprises a third secondary winding and a fourth diode of the transformer; the homonymous end of the third secondary winding is connected with the second end of the energy storage capacitor; the synonym end of the third secondary winding is connected with the anode of the fourth diode, and the cathode of the fourth diode is connected with the first end of the energy storage capacitor;

10. The priming system of any one of claims 1 to 9, further comprising a contactor controller;

11. The priming system of any one of claims 1 to 9, further comprising a contactor controller;

12. The pre-charging control method of the high-voltage loop capacitor is characterized by being applied to a pre-charging system of the high-voltage loop capacitor, wherein the pre-charging system comprises a power battery, a main positive contactor, a main negative contactor, a DC-DC module and a load energy storage capacitor; the first end of the main positive contactor is connected with the positive electrode of the power battery and the first end of the DC-DC module, and the second end of the main positive contactor is connected with the second end of the DC-DC module and the first end of the load energy storage capacitor; the first end of the main negative contactor is connected with the negative electrode of the power battery and the third end of the DC-DC module, the second end of the main negative contactor is connected with the fourth end of the DC-DC module and the second end of the load energy storage capacitor, and the pre-charging control method comprises the following steps:

13. The method of claim 12, wherein the high-voltage loop capacitor priming system further comprises a contactor controller, the method further comprising:

14. The method of claim 12, wherein the high-voltage loop capacitor priming system further comprises a contactor controller, the method further comprising:

15. A vehicle characterized by comprising a pre-charge system of a high voltage loop capacitor according to any one of claims 1 to 11.