CN113335096A

CN113335096A - CC/CP diagnostic circuit and charger

Info

Publication number: CN113335096A
Application number: CN202110687446.6A
Authority: CN
Inventors: 冯颖盈; 姚顺; 刘骥; 刘剑
Original assignee: Shenzhen Vmax Power Co Ltd
Current assignee: Shenzhen Vmax Power Co Ltd; Shenzhen VMAX New Energy Co Ltd
Priority date: 2021-06-21
Filing date: 2021-06-21
Publication date: 2021-09-03

Abstract

The invention provides a CC/CP (communication control/charge control) diagnosis circuit and a charger, wherein the CC/CP diagnosis circuit comprises a main power circuit, a power supply circuit connected with the main power circuit and a diagnosis circuit connected with a CC line and a CP line, the diagnosis circuit comprises a plurality of voltage detection points, and the fault state of the CC line and/or the CP line is determined by detecting the voltages of the voltage detection points. Compared with the prior art, the CC/CP diagnostic circuit can accurately identify the faults of the CC line and the CP line, avoid wrong information interaction between a charging pile and a charger, and improve the safety of the charger.

Description

CC/CP diagnostic circuit and charger

Technical Field

The invention relates to the technical field of electric vehicle charging, in particular to a CC/CP (continuous current/continuous current) diagnosis circuit and a charger.

Background

With the requirements of energy conservation and emission reduction and air pollution control, new energy automobiles are gradually commercialized in the market, and electric automobiles are more the main force of the new energy automobiles. As an important part of the electric automobile, the charger is used for converting electric energy of a power grid into battery energy storage of the electric automobile. Before the charging machine and the charging pile are connected, information interaction is carried out through a CC signal (Connection Confirm) and a CP signal (Control Pilot) to ensure Connection. However, for the electric vehicle, when the CC/CP signal is open or short-circuited with the vehicle body, error information interaction between the charging pile and the charging machine may be caused, the charging machine and the charging pile may not accurately identify the fault state, and even the fault connection state may be incorrectly identified as a normal connection, so as to initiate a charging request.

Patent CN210626574U proposes an ac charging pile fault detection device, which can only be used for detecting the fault of the ac charging pile end, and cannot detect the fault of the car end, nor obtain the specific fault information thereof.

Therefore, how to provide a CC/CP diagnostic circuit and a charger, which can accurately identify various fault states, is an urgent technical problem to be solved in the industry.

Disclosure of Invention

The invention provides a CC/CP (continuous current/continuous current) diagnosis circuit and a charger, aiming at the problem that fault information cannot be accurately detected in the prior art.

The technical scheme of the invention is that the CC/CP diagnostic circuit comprises a main power circuit, a power supply circuit connected with the main power circuit and a diagnostic circuit connected with a CC line and a CP line, wherein the diagnostic circuit comprises a plurality of voltage detection points, and the fault state of the CC line and/or the CP line is determined by detecting the voltages of the voltage detection points.

Further, the diagnostic circuit comprises a resistor R5 and a resistor R6 which are connected with the CC line, and a third voltage detection point and a fourth voltage detection point which are arranged between the resistor R5 and the resistor R6 and the CC line, and when the voltage of the third voltage detection point and/or the fourth voltage detection point is abnormal, the CC line is in fault.

Further, the CC circuit comprises a CC1 circuit and a CC2 circuit which are connected with each other, one end of the resistor R5 is connected to the CC1 circuit, the other end of the resistor R6 is connected to the CC2 circuit, and the other end of the resistor R6 is connected to the ground after being connected with the switch S7 in series;

the third voltage detection point is arranged between the resistor R5 and the CC1 line, and the fourth voltage detection point is arranged between the resistor R6 and the CC2 line.

Further, when the charger is subjected to power-on self-test, 3 fault states are determined according to the voltage states of the third voltage detection point and the fourth voltage detection point, wherein the three fault states are respectively as follows:

when the voltages of the third voltage detection point and the fourth voltage detection point are the same and 0V is applied before and after the switch S7 is closed, it is determined that the first fault state is: a CC line fault is shorted to ground;

when the voltages of the third voltage detection point and the fourth voltage detection point are the same and the power input voltage is applied before and after the switch S7 is closed, determining that the fault state is a second fault state: the CC circuit is short-circuited to the power supply input in a fault mode;

when the third voltage detection point is the power input voltage before and after the switch S7 is closed, and the fourth voltage detection point is 0V after the switch S7 is closed, it is determined as a third fault state: the CC line has an open circuit fault.

Further, when the main power circuit is in a charging state, 4 fault states are determined according to the voltage states of the third voltage detection point and the fourth voltage detection point, wherein the four fault states are respectively as follows:

when the voltages of the third voltage detection point and the fourth voltage detection point are the same and are both 0V, determining that the fault state is a first fault state: a CC line fault is shorted to ground;

when the voltages of the third voltage detection point and the fourth voltage detection point are the same and are power supply input voltages, determining that the fault state is a second fault state: the CC circuit is short-circuited to the power supply input in a fault mode;

when the voltage of the third voltage detection point is the power supply input voltage and the voltage of the fourth voltage detection point is 0V, determining that the fault state is a fourth fault state: open circuit fault of CC1 circuit;

when the voltage of the third voltage detection point is unchanged and the voltage of the fourth voltage detection point is reduced to 0V, determining that a fifth fault state is formed: the CC2 line has an open circuit fault.

Further, the diagnosis circuit comprises a resistor R1 and a resistor R3 connected with the CP line, and a second voltage detection point and a fifth voltage detection point which are arranged between the resistor R1 and the resistor R3 and the CP line, and when the voltage of the second voltage detection point and/or the fifth voltage detection point is abnormal, the CP line is in fault.

Further, the CP line comprises a CP1 line and a CP2 line, one end of the resistor R1 is connected to the CP1 line, the other end of the resistor R1 is connected in series with a switch S2 and then is connected to the ground, the diagnostic circuit further comprises a resistor R2 and a switch S4 which are connected in parallel to two ends of the resistor R1 and the switch S2, and the resistor R2 is connected in parallel with the resistor R1 and then is divided; one end of the resistor R3 is connected to the CP2 line, and the other end of the resistor R3 is connected to the ground after being connected in series with a switch S6;

the second voltage detection point is arranged between the resistor R1 and a CP1 line, and the fifth voltage detection point is arranged between the resistor R3 and a CP2 line;

a switch S5 is connected between the second voltage detection point and the CP1 line, and one end of the switch S5 is connected between the second voltage detection point and the CP1 line and the other end is connected to a power input.

Further, when the charger is subjected to power-on self-test, 3 fault states are determined according to the voltage states of the second voltage detection point and the fifth voltage detection point, wherein the three fault states are respectively as follows:

when the voltages of the second voltage detection point and the fifth voltage detection point are the same and 0V is present before and after the switch S5 is closed, it is determined that the fault state is a sixth fault state: CP line fault shorting to ground;

when the voltages of the second voltage detection point and the fifth voltage detection point are the same and the power input voltage is applied before and after the switch S5 is closed, a seventh fault state is determined: the CP line fault is short-circuited to the power supply input;

when the voltages of the second voltage detection point and the fifth voltage detection point are both 0V before the switch S5 is closed, and after the switch S5 is closed, the voltage of the second voltage detection point becomes the power input voltage, and the voltage of the fifth voltage detection point is still 0V, it is determined as an eighth fault state: the CP line has an open circuit fault.

Further, when the main power circuit is in a charging state, 4 fault states are determined according to the voltage states of the second voltage detection point and the fifth voltage detection point, wherein the four fault states are respectively as follows:

when the voltages of the second voltage detection point and the fifth voltage detection point are the same and are both 0V, determining that the fault state is a sixth fault state: CP line fault shorting to ground;

when the voltages of the second voltage detection point and the fifth voltage detection point are the same and are power supply input voltages, determining that the fault state is a seventh fault state: the CP line fault is short-circuited to the power supply input;

when the voltage of the second voltage detection point is 0V and the voltage of the fifth voltage detection point is the power supply input voltage, determining that the fault state is a ninth fault state: open circuit fault of CP1 line;

when the voltage of the second voltage detection point is unchanged and the voltage of the fifth voltage detection point is reduced to 0V, determining that a tenth fault state is formed: the CP2 line has an open circuit fault.

The invention also provides a charger, when the charger finishes the interactive connection with the CC signal and the CP signal of the charging pile through the CC line and the CP line, the charger starts to charge;

when at least one of the CC line and the CP line has a fault, the charger stops the charging mode;

the charger diagnoses the faults of the CC line and the CP line by adopting the CC/CP diagnosis circuit.

Compared with the prior art, the invention has at least the following beneficial effects:

the invention provides a diagnosis circuit connected with a CC line and a CP line, wherein a plurality of voltage detection points are arranged on the diagnosis circuit, faults in the circuit can be accurately identified by detecting the voltage of each voltage detection point, and the safety of a charger is improved.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the embodiments or the prior art descriptions will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive exercise.

FIG. 1 is a schematic diagram of the CC/CP signal self-test diagnosis before the charging gun is inserted;

FIG. 2 is a schematic diagram of the CC/CP signal diagnosis after the charging of the charging gun according to the present invention;

here, detection point 1 represents a first voltage detection point, detection point 2 represents a second voltage detection point, detection point 3 represents a third voltage detection point, detection point 4 represents a fourth voltage detection point, and detection point 5 represents a fifth voltage detection point.

Detailed Description

In order to make the technical problems, technical solutions and advantageous effects to be solved by the present invention more clearly apparent, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Thus, a feature indicated in this specification will serve to explain one of the features of one embodiment of the invention, and does not imply that every embodiment of the invention must have the stated feature. Further, it should be noted that this specification describes many features. Although some features may be combined to show a possible system design, these features may also be used in other combinations not explicitly described. Thus, the combinations illustrated are not intended to be limiting unless otherwise specified.

The principles and construction of the present invention will be described in detail below with reference to the drawings and examples.

The existing charger and the charging pile can carry out information interaction through a CC signal and a CP signal before connection is established, but for an electric automobile, when the CC/CP signal is open or short-circuited with an automobile body, error information interaction between the charging pile and the charger can be caused, the charger and the charging pile can not accurately identify a fault state, the fault connection state can be incorrectly identified as correct connection, a charging request is initiated, and various problems are caused. The invention provides a CC/CP diagnostic circuit, which accurately determines the fault of a CC/CP circuit through a plurality of voltage detection points arranged on the diagnostic circuit, and improves the charging safety of a charger.

Referring to fig. 1, the present invention provides a CC/CP diagnostic circuit, which includes a main power circuit and a power supply circuit (not shown) connected to the main power circuit, wherein the power supply circuit is connected to the main power circuit to charge the main power circuit. The diagnostic circuit is connected with the CC line and the CP line, wherein the CC line is used for information interaction of CC signals, the CP line is used for information interaction of CP signals, and the diagnostic circuit is used for detecting the states of the CC line and the CP line. As can be seen from fig. 1, the present invention has a plurality of voltage detection points, which are respectively a detection point 2, a detection point 3, a detection point 4, and a detection point 5 (the detection point 2 is a second voltage detection point, the detection point 3 is a third voltage detection point, the detection point 4 is a fourth voltage detection point, and the detection point 5 is a fifth voltage detection point), and by detecting voltages of the plurality of voltage detection points, states of the CC line and the CP line can be accurately determined, and when the diagnostic circuit determines that the CC line and/or the CP line have a fault, the diagnostic circuit can send a signal to the charging device, and then disconnect the power supply circuit to stop charging the main power circuit.

The CC circuit comprises a CC1 circuit and a CC2 circuit, wherein the CC1 circuit is used for realizing information interaction of CC signals, the CC1 circuit is mainly used for diagnosing the state of the CC1 circuit, and the CC2 circuit is an auxiliary diagnostic circuit and can be used for further determining the state of the CC1 circuit. The diagnostic circuit is provided with an input power supply which is used for providing input voltage, and the power supply voltage of +12V or the PWM signal input of 12V is adopted in the invention. Referring to fig. 1, the diagnostic circuit includes a resistor R5 connected to the CC1 line and a resistor R6 connected to the CC2 line.

Specifically, the resistor R5 has one end connected to the input power supply and the other end connected to the CC1 line as a matching resistor for detecting the CC1 signal, and the resistor R6 has one end connected to the CC2 line and the other end connected in series to the switch S7 and then connected to the ground as a matching resistor for detecting the CC2 signal. The third voltage detecting point is arranged between the R5 and the CC1 line, and the fourth voltage detecting point is arranged between the R6 and the CC2 line.

Referring to fig. 1, when the charger is powered on for self-test, the CC circuit test principle is as follows:

after the charger is awakened, when a CC circuit is in a normal condition, when a switch S7 is disconnected, the resistor R6 has no voltage, at the moment, because the third voltage detection point is connected with an input power supply (12V), the third voltage detection point can detect the voltage of 12V, the fourth voltage detection point detects the voltage of 0V, after the switch S7 is closed, the resistor R5 and the resistor R6 form a passage and equally divide the voltage of the input power supply, at the moment, the third voltage detection point and the fourth voltage detection point are connected to the same potential, and the voltage is equal to the voltage

。

Meanwhile, in this case, 3 fault states can be determined according to the voltage states of the third voltage detection point and the fourth voltage detection point (only 3 fault states exist in practical application, and 3 faults can be accurately identified in the present invention), which are:

in this case, since the voltages at the third voltage detection point and the fourth voltage detection point are not affected by the input power supply and are constant at 0, it is indicated that the voltage output by the power supply is pulled down to 0 (if the CC circuit is open, the third voltage detection point should have a voltage, so the case is not open-circuit fault), so that it can be determined that the CC circuit is short-circuited and connected to the vehicle body ground (first fault state).

When the voltages of the third voltage detection point and the fourth voltage detection point are the same and the power input voltage is applied before and after the switch S7 is closed, determining that the fault state is a second fault state: a CC line fault is shorted to the power input (battery of electric vehicle, generally 12V);

under the condition, the voltages at the third voltage detection point and the fourth voltage detection point are not influenced by an input power supply, and the voltages are constant to 12V (power supply input voltage), so that the third voltage detection point and the fourth voltage detection point are connected with a voltage input under the condition and are not influenced by the input power supply, and the 12V voltage power supply (second fault state) that the CC circuit is connected to the whole vehicle in a short circuit mode can be judged.

In this case, it can be seen that the voltage at the third voltage detecting point is not affected by the voltage division by the resistor R6 and is kept constant at the power input voltage, and the resistor R6 is open at this time, so that it can be determined that the CC line has an open circuit fault (third fault state).

Through the voltage of the third voltage detection point and the fourth voltage detection point before and after the detection switch S7 is closed, various fault problems of the CC circuit can be accurately identified, and the safety of the charging circuit is greatly improved.

Referring to fig. 2, the principle of CC line detection in the charging state is as follows:

when the charging gun is inserted, the main power circuit is in a charging state, when the CC circuit is in a normal condition, the switch S3 of the CC circuit is in a closed state, the third voltage detection point and the fourth voltage detection point are at the same potential and have the same voltage, and the third voltage detection point and the fourth voltage detection point are both at the same potential and have the same voltage

。

Meanwhile, in this case, 4 fault states can be determined according to the voltage states of the third voltage detection point and the fourth voltage detection point, which are respectively:

in this case, the voltages at the third voltage detection point and the fourth voltage detection point are not affected by the input power supply, and the voltage is constant at 0, which means that the voltage output by the power supply is pulled down to 0, and thus it can be determined that the CC line fault is shorted to ground (first fault state).

in this case, the voltages at the third voltage detection point and the fourth voltage detection point are not affected by the input power, and the third voltage detection point and the fourth voltage detection point are electrically connected to a constant voltage input, so that it can be determined that the CC line is short-circuited to the 12V voltage supply of the entire vehicle (second fault state) at this time.

in this case, since the voltage at the third voltage detecting point is 12V (voltage input voltage), which indicates that it is not affected by the resistor R6 and the resistor RC voltage division in the charging gun, it can be seen that the CC1 line is disconnected from the resistor R6 and the resistor RC, that is, it can be determined that the open fault (fourth fault state) occurs in the CC1 line.

In this case, the voltage at the third voltage detecting point is still maintained at the voltage in the normal condition, which indicates that the resistor RC in the charging gun has a voltage dividing function and divides the voltage of the resistor R5, which indicates that the CC1 line is normal, and the voltage at the fourth voltage detecting point becomes 0, which indicates that the voltage input voltage is not received, so that it can be determined that the CC2 line has an open circuit fault (fifth fault state).

The third fault condition is determined at power-on self-test of the diagnostic circuit, which can only determine that the CC line is open circuit fault and cannot determine whether the CC1 line or the CC2 line is open circuit. The fourth fault state and the fifth fault state are determined by detection in the charging state, which can accurately identify whether the CC1 line or the CC2 line has a fault.

When the charging gun is inserted into a charging state, the problem of faults on the CC circuit can be accurately determined by detecting the voltage changes of the third voltage detection point and the fourth voltage detection point, and the safety of the charger is further improved.

When the CC circuit is judged to be in an abnormal state, the charger can report the CC circuit to the vehicle controller in time for processing, and the charging state is disconnected, so that the occurrence of subsequent problems is avoided.

Referring to fig. 1, the CP line includes CP1 line and CP2 line, and a resistor R1 and a resistor R3 connected to the CP1 line and the CP2 line. The CP1 line serves as a main test line, and the CP2 line serves as an auxiliary test line, similarly to the CC line, to confirm the state of the CP1 line.

Specifically, one end of a resistor R1 is connected to a CP1 line, the other end of the resistor R1 is connected in series with a switch S2 and then grounded, two ends of a resistor R1 and a switch S2 are connected in parallel with a resistor R2 and a switch S4, one end of a resistor R3 is connected to the CP2 line, and the other end of the resistor R3 is connected in series with a switch S6 and then grounded. Here, the switch S2 and the switch S4 are CP switches required by the national standard, the resistor R1 and the resistor R2 are matched resistors for CP1 signal detection, and the resistor R3 is matched resistors for CP2 signal detection. The diagnostic circuit is further provided with a switch S5, one end of which is connected between the CP1 line and the resistor R1, and the other end of which is connected to the input power supply (12V), and which forms a logic changeover switch for the CC/CP signal together with the switch S6 and the switch S7. Diodes are also provided in the CP1 and CP2 lines, which are mainly used for protection. The second voltage detection point is disposed between the resistor R1 and the CP1 line, and the fifth voltage detection point is disposed between the resistor R3 and the CP2 line.

Referring to fig. 1, after the charger is awakened, the switch S2 and the switch S6 are closed, when the CP line is in a normal state, before the logic switch S5 is closed, since the CP line is connected to the input power supply, the voltages at the second voltage detection point and the fifth voltage detection point are both 0V, and after the switch S5 is closed, the influence of the diode conduction voltage drops on the CP1 line and the CP2 line is ignored, the second voltage detection point and the fifth voltage detection point are both connected to the input power supply, and both the second voltage detection point and the fifth voltage detection point are at the same potential and are 12V.

Meanwhile, in this case, 3 fault states can be determined according to the voltage states of the second voltage detection point and the fifth voltage detection point (only 3 fault states exist in practical application, and the present invention can accurately detect 3 fault states), which are:

in this case, since the second voltage detection point and the fifth voltage detection point are connected to the input power source and the voltage thereof is constant at 0 when the switch S5 is closed, it can be seen that the voltages at the second voltage detection point and the fifth voltage detection point are pulled down to 0, that is, the second voltage detection point and the fifth voltage detection point are turned on to the ground, and it can be determined that the CP line fault is shorted to the vehicle body ground (sixth fault state).

in this case, it can be determined that the CP line provides a voltage input because of the presence of voltages at the second voltage detection point and the fifth voltage detection point before the switch S5 is closed, and that the CP line fault is shorted to the 12V voltage supply of the entire vehicle because of its constant voltage of 12V (seventh fault state).

In this case, since the voltage at the second voltage detecting point is affected by the switch S5, it can be determined that the CP line is not short-circuited to the ground, and the voltage at the fifth voltage detecting point is constant at 0, it can be seen that the voltage inputted from the power supply is not transmitted to the fifth voltage detecting point, and since the input voltage is transmitted to the second voltage detecting point without passing through the CP line, it can be determined that the fault is in the CP line, and since the voltage at the fifth voltage detecting point is 0, it can be determined that the open fault (eighth fault state) occurs in the CP line.

Through the voltage change on the second voltage detection point and the fifth voltage detection point before and after the switch S5 is closed, the fault information of the CP circuit can be accurately identified, and the safety of the charging circuit is improved.

Referring to fig. 2, the CP line detection principle in the charging state is as follows:

when a charging gun is inserted and the main power circuit is in a charging state, in a normal state, the diagnosis logic switches S5 and S6 are disconnected, the switch S1, the switch S2 and the switch S4 are closed, at the moment, the circuit is powered by the charging pile, the resistor R2 is connected in parallel with the resistor R1 and then connected in series with a 1K resistor in the charging pile, the second voltage detection point and the fifth voltage detection point are arranged between the resistor R2 and the 1K resistor, the voltage of the second voltage detection point and the fifth voltage detection point is the voltage after voltage division, the resistor R1 is 1.3K ohm, the resistor R2 is 3.01K ohm, the voltage of the second voltage detection point and the fifth voltage detection point after voltage division of the 1K resistor is 6V, namely, in a normal case, the voltage of the second voltage detection point and the fifth voltage detection point is 6V.

The charging pile is provided with a first voltage detection point, the first voltage detection point is arranged at an output port of the charging pile and used for detecting the state of the charging pile, when the voltage of the first voltage detection point is 0, the charging pile is indicated to have a fault, and when the voltage of the first voltage detection point is 12V, the charging pile is indicated to be normal.

When charging pile is normal, 4 fault states can be judged according to the voltage states of the second voltage detection point and the fifth voltage detection point, which are respectively as follows:

in this case, since the voltages of the second voltage detection point and the fifth voltage detection point are constant at 0, which indicates that the output voltage of the charging post is pulled low, that is, the second voltage detection point and the fifth voltage detection point are connected to the ground, it can be determined that the CP line fault is shorted to the ground (sixth fault state).

in this case, since there is voltage at the second voltage detection point and the fifth voltage detection point, which indicates that the CP line has no open-circuit fault, and the voltage is constant at 12V, which indicates that the voltage at the second voltage detection point and the fifth voltage detection point is not divided by the 1K resistor on the charging pile, i.e., it is connected to the power supply, it can be determined that the CP line has a fault and is open-circuit connected to the power supply input, i.e., 12V power supply (seventh fault state).

in this case, the voltage at the second voltage detecting point is 0, indicating that the CP line has an open-circuit fault, but the voltage at the fifth voltage detecting point is 12V, indicating that the CP2 line is normal, so that it can be determined that the CP1 line has an open-circuit fault (ninth fault state).

In this case, since the voltage at the second voltage detecting point is not changed and is still maintained at the voltage 6V in the normal state, it indicates that the CP1 line is not broken, and the voltage at the fifth voltage detecting point is 0, which indicates that the fifth voltage detecting point thereof does not receive the input voltage, it can be determined that the CP2 line has an open fault (tenth fault state).

The eighth fault state is determined at the time of power-on self-test of the CP line, which can only determine that the CP line has an open-circuit fault and cannot determine whether the CP1 line or the CP2 line has a fault, like the CC line detection principle, while the ninth fault state and the tenth fault state are used for fault detection in the charging state, which can accurately identify faults of the CP1 line and the CP2 line.

A person skilled in the art can determine the faults of the CC line and the CP line through a self-checking mode, and if the specific faults cannot be accurately determined in the self-checking mode, a charging gun can be inserted to detect the specific faults of the CC line and the CP line.

Referring to fig. 2, L1, L2 and L3 are live wires, N is a zero line, and serve as a power supply circuit for supplying power to the main power circuit, a plurality of switches are arranged between the power supply circuit and the main power circuit, when the CC/CP diagnostic circuit determines that a fault exists in the CC line and/or the CP line, the charger can detect an abnormal state in time and report the abnormal state to the vehicle controller, and at this time, the plurality of switches between the power supply circuit and the main power circuit are turned off to stop supplying power to the main power circuit.

The CC/CP diagnostic circuit provided by the invention can be used for respectively carrying out CC line and CP line detection under the charging state when the charging gun is not inserted and the charging state when the charging gun is inserted, and the voltage of each voltage detection point is different for each fault state, so that the specific fault can be accurately judged according to the specific voltage state of each voltage detection point, and a user can overhaul the specific fault, thereby greatly improving the safety of a charger.

Compared with the prior art, the method and the device can accurately identify the circuit fault, avoid wrong information interaction between the charger and the charging pile, and effectively improve the safety of the charger.

The above embodiments are only intended to illustrate specific embodiments of the present invention, and it should be noted that, for those skilled in the art, many modifications and changes can be made without departing from the spirit of the present invention, and these modifications and changes should fall into the protection scope of the present invention.

Claims

1. A CC/CP diagnostic circuit comprises a main power circuit and a power supply circuit connected with the main power circuit, and is characterized by further comprising a diagnostic circuit connected with a CC line and a CP line, wherein the diagnostic circuit comprises a plurality of voltage detection points, and the fault state of the CC line and/or the CP line is determined by detecting the voltages of the voltage detection points.

2. The CC/CP diagnostic circuit of claim 1, wherein the diagnostic circuit comprises a resistor R5 and a resistor R6 connected to the CC line, and a third voltage detection point and a fourth voltage detection point provided between the resistor R5 and the resistor R6 and the CC line, wherein the CC line is failed when the voltage of the third voltage detection point and/or the fourth voltage detection point is abnormal.

3. The CC/CP diagnostic circuit of claim 2, wherein the CC lines comprise a CC1 line and a CC2 line which are connected with each other, one end of the resistor R5 is connected to a CC1 line, the other end is connected with a power input, one end of the resistor R6 is connected to the CC2 line, and the other end is connected to the ground after being connected with a switch S7 in series;

4. The CC/CP diagnostic circuit according to claim 3, wherein when the charger is powered on for self-test, 3 fault states are determined according to the voltage states of the third voltage detection point and the fourth voltage detection point, which are respectively:

5. The CC/CP diagnostic circuit of claim 3, wherein when the main power circuit is in a charging state, 4 fault states are determined according to the voltage states of the third voltage detection point and the fourth voltage detection point, respectively:

6. The CC/CP diagnostic circuit of claim 1, wherein the diagnostic circuit comprises a resistor R1 and a resistor R3 connected to the CP line, and a second voltage detection point and a fifth voltage detection point provided between the resistor R1 and the resistor R3 and the CP line, wherein the CP line is failed when the voltage of the second voltage detection point and/or the fifth voltage detection point is abnormal.

7. The CC/CP diagnostic circuit of claim 6, wherein the CP line comprises a CP1 line and a CP2 line, one end of the resistor R1 is connected to the CP1 line, the other end is connected in series with a switch S2 and then connected to the ground, the diagnostic circuit further comprises a resistor R2 and a switch S4 which are connected in parallel to two ends of the resistor R1 and the switch S2, the resistor R2 is used for dividing voltage after being connected in parallel with the resistor R1; one end of the resistor R3 is connected to the CP2 line, and the other end of the resistor R3 is connected to the ground after being connected in series with a switch S6;

8. The CC/CP diagnosis circuit according to claim 7, wherein when the charger is powered on for self-test, there are 3 fault states determined according to the voltage states of the second voltage detection point and the fifth voltage detection point, which are respectively:

9. The CC/CP diagnostic circuit of claim 7, wherein when the main power circuit is in a charging state, 4 fault states are determined according to the voltage states of the second voltage detection point and the fifth voltage detection point, respectively:

10. The charging machine is characterized in that when the charging machine finishes the interactive connection with the CC signal and the CP signal of the charging pile through the CC line and the CP line, the charging machine starts to charge;

the charger adopts the CC/CP diagnostic circuit of any claim from 1 to 9 to diagnose the fault of the CC line and the CP line.