A CC / CP diagnostic circuit and charger

Abstract

The present invention proposes a CC / CP diagnostic circuit and charger. The CC / CP diagnostic circuit includes a main power circuit, a power supply circuit connected to the main power circuit, and a diagnostic circuit connected to the CC and CP lines. The diagnostic circuit includes multiple voltage detection points and determines the fault status of the CC and / or CP lines by detecting the voltages at these detection points. Compared with the existing technology, the present invention provides a CC / CP diagnostic circuit that can accurately identify CC and CP line faults, avoids erroneous information exchange between the charging station and the charger, and improves the safety of the charger.

Description

Technical Field

[0001] The present invention relates to the technical field of electric vehicle charging, in particular to a CC / CP diagnostic circuit and a charger. Background Art

[0002] With the need to reduce energy consumption, emissions, and air pollution, new energy vehicles are gradually gaining commercial adoption, with electric vehicles being the primary force. As a key component of electric vehicles, the charger converts grid power into energy for storage in the electric vehicle's batteries. Before establishing a connection, the charger and charging pile exchange information via CC (Connection Confirm) and CP (Control Pilot) signals to ensure connectivity. However, for electric vehicles, if the CC / CP signals become open or short-circuited to the vehicle body, this can cause erroneous information exchange between the charger and the charging pile. Consequently, the charger and charging pile may be unable to accurately identify the fault state, or even mistakenly identify a faulty connection as a normal connection and initiate a charging request.

[0003] Patent CN210626574U proposes an AC charging pile fault detection device, which can only be used to detect faults on the AC charging pile side, but cannot detect faults on the vehicle side, nor can it obtain specific fault information.

[0004] Therefore, how to propose a CC / CP diagnostic circuit and charger that can accurately identify various fault conditions is a technical problem that needs to be solved urgently in the industry. Summary of the Invention

[0005] In view of the problem that the prior art cannot accurately detect fault information, the present invention proposes a CC / CP diagnostic circuit and a charger.

[0006] The technical solution of the present invention is to propose a CC / CP diagnostic circuit, which includes a main power circuit and a power supply circuit connected to the main power circuit, and also includes a diagnostic circuit connected to the CC line and the CP line. The diagnostic circuit includes multiple voltage detection points and determines the fault status of the CC line and / or CP line by detecting the voltages at the voltage detection points.

[0007] Furthermore, the diagnostic circuit includes resistors R5 and R6 connected to the CC line, and a third voltage detection point and a fourth voltage detection point arranged between the resistors R5 and R6 and the CC line. When the voltage at the third voltage detection point and / or the fourth voltage detection point is abnormal, the CC line fails.

[0008] Furthermore, the CC circuit includes a CC1 circuit and a CC2 circuit connected to each other, one end of the resistor R5 is connected to the CC1 circuit and the other end is connected to the power input, and one end of the resistor R6 is connected to the CC2 circuit and the other end is connected in series with a switch S7 and then connected to ground;

[0009] The third voltage detection point is located between the resistor R5 and the CC1 circuit, and the fourth voltage detection point is located between the resistor R6 and the CC2 circuit.

[0010] Furthermore, when the charger performs a power-on self-test, three fault states are determined based on the voltage states of the third voltage detection point and the fourth voltage detection point, namely:

[0011] When the voltages of the third voltage detection point and the fourth voltage detection point are the same and are both 0V before and after the switch S7 is closed, it is determined to be a first fault state: the CC line is shorted to ground;

[0012] When the voltages at the third voltage detection point and the fourth voltage detection point are the same and both are the power input voltage before and after the switch S7 is closed, it is determined to be a second fault state: the CC line is shorted to the power input;

[0013] When the third voltage detection point is at the power input voltage before and after the switch S7 is closed, and the voltage at the fourth voltage detection point is 0V after the switch S7 is closed, it is determined to be a third fault state: a CC line open circuit fault occurs.

[0014] Furthermore, when the main power circuit is in a charging state, there are four fault states determined according to the voltage states of the third voltage detection point and the fourth voltage detection point, namely:

[0015] When the voltages of the third voltage detection point and the fourth voltage detection point are the same and both are 0V, it is determined to be a first fault state: the CC line is shorted to ground;

[0016] When the voltages of the third voltage detection point and the fourth voltage detection point are the same and both are the power input voltage, it is determined to be a second fault state: the CC line fault is shorted to the power input;

[0017] When the voltage at the third voltage detection point is the power input voltage and the voltage at the fourth voltage detection point is 0V, it is determined to be a fourth fault state: a circuit breaker fault occurs in the CC1 line;

[0018] When the voltage at the third voltage detection point remains unchanged and the voltage at the fourth voltage detection point drops to 0V, it is determined to be a fifth fault state: a circuit breaker fault occurs in the CC2 line.

[0019] Furthermore, the diagnostic circuit includes resistors R1 and R3 connected to the CP line, and a second voltage detection point and a fifth voltage detection point arranged between the resistors R1 and R3 and the CP line. When the voltage at the second voltage detection point and / or the fifth voltage detection point is abnormal, the CP line fails.

[0020] Furthermore, the CP circuit includes a CP1 circuit and a CP2 circuit. One end of the resistor R1 is connected to the CP1 circuit, and the other end is connected in series with a switch S2 and then connected to ground. The diagnostic circuit also includes a resistor R2 and a switch S4 connected in parallel to the resistor R1 and the switch S2. The resistor R2 is used to divide the voltage after being connected in parallel with the resistor R1. One end of the resistor R3 is connected to the CP2 circuit, and the other end is connected in series with a switch S6 and then connected to ground.

[0021] The second voltage detection point is set between the resistor R1 and the CP1 circuit, and the fifth voltage detection point is set between the resistor R3 and the CP2 circuit;

[0022] A switch S5 is further connected between the second voltage detection point and the CP1 line. 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 the power input.

[0023] Furthermore, when the charger performs a power-on self-test, three fault states are determined based on the voltage states of the second voltage detection point and the fifth voltage detection point, namely:

[0024] When the voltages of the second voltage detection point and the fifth voltage detection point are the same and are both 0V before and after the switch S5 is closed, it is determined to be a sixth fault state: the CP line is shorted to ground;

[0025] When the voltages of the second voltage detection point and the fifth voltage detection point are the same and both are the power input voltage before and after the switch S5 is closed, it is determined to be a seventh fault state: the CP line is shorted to the power input;

[0026] When the voltages at the second voltage detection point and the fifth voltage detection point are both 0 V before the switch S5 is closed, and after the switch S5 is closed, the voltage at the second voltage detection point becomes the power supply input voltage, and the voltage at the fifth voltage detection point is still 0 V, it is determined to be an eighth fault state: a circuit breaker fault occurs in the CP line.

[0027] Furthermore, when the main power circuit is in a charging state, there are four fault states determined according to the voltage states of the second voltage detection point and the fifth voltage detection point, namely:

[0028] When the voltages of the second voltage detection point and the fifth voltage detection point are the same and both are 0V, it is determined to be a sixth fault state: the CP line is shorted to ground;

[0029] When the voltages of the second voltage detection point and the fifth voltage detection point are the same and both are the power input voltage, it is determined to be a seventh fault state: the CP line fault is shorted to the power input;

[0030] When the voltage at the second voltage detection point is 0V and the voltage at the fifth voltage detection point is the power input voltage, it is determined to be a ninth fault state: a circuit breaker fault occurs in the CP1 line;

[0031] When the voltage at the second voltage detection point remains unchanged and the voltage at the fifth voltage detection point drops to 0V, it is determined to be a tenth fault state: a circuit breaker fault occurs on the CP2 line.

[0032] The present invention further provides a charger, which starts charging when the charger completes interactive connection with the CC signal and CP signal of the charging pile through the CC line and the CP line;

[0033] When at least one of the CC line and the CP line fails, the charger stops the charging mode;

[0034] The charger uses the CC / CP diagnostic circuit to diagnose faults in the CC and CP lines.

[0035] Compared with the prior art, the present invention has at least the following beneficial effects:

[0036] The present invention proposes a diagnostic circuit connected to the CC line and the CP line. Multiple voltage detection points are set on the diagnostic circuit. By detecting the voltage at each voltage detection point, faults in the circuit can be accurately identified, thereby improving the safety of the charger. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0038] Figure 1 This is a schematic diagram of the CC / CP signal self-diagnosis principle before the charging gun is plugged in.

[0039] Figure 2 This is a CC / CP signal diagnosis principle diagram after charging with the charging gun of the present invention;

[0040] Among them, detection point 1 represents the first voltage detection point, detection point 2 represents the second voltage detection point, detection point 3 represents the third voltage detection point, detection point 4 represents the fourth voltage detection point, and detection point 5 represents the fifth voltage detection point. DETAILED DESCRIPTION

[0041] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, 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 only used to explain the present invention and are not intended to limit the present invention.

[0042] Thus, a feature indicated in this specification is intended to illustrate one of the features of one embodiment of the present invention, rather than to imply that every embodiment of the present invention must have the described feature. In addition, it should be noted that this specification describes many features. Although certain features can be combined together to illustrate possible system designs, these features can also be used in other, not explicitly described, combinations. Thus, unless otherwise noted, the described combinations are not intended to be limiting.

[0043] The principle and structure of the present invention are described in detail below with reference to the accompanying drawings and embodiments.

[0044] Before establishing a connection, existing chargers and charging piles exchange information via CC and CP signals to ensure connectivity. However, for electric vehicles, if the CC / CP signals become open or short-circuited to the vehicle body, this can cause incorrect information exchange between the charger and the charging pile. The charger and charging pile are unable to accurately identify the fault state and may mistakenly identify a faulty connection as a correct connection, initiating a charging request and causing various problems. The present invention proposes a CC / CP diagnostic circuit that, through multiple voltage detection points set within the diagnostic circuit, accurately identifies CC / CP line faults, thereby improving charging safety for the charger.

[0045] See Figure 1 The present invention proposes a CC / CP diagnostic circuit, which includes a main power circuit and a power supply circuit (not shown in the figure) connected to the main power circuit. The power supply circuit is connected to the main power circuit to charge the main power circuit. It also includes a diagnostic circuit connected to the CC line and the CP line, wherein the CC line is used for information exchange of CC signals and the CP line is used for information exchange of CP signals. The diagnostic circuit is used to detect the status of the CC line and the CP line. Figure 1As can be seen from the figure, the present invention is provided with multiple voltage detection points, namely detection point 2, detection point 3, detection point 4, and detection point 5 (detection point 2 is the second voltage detection point, detection point 3 is the third voltage detection point, detection point 4 is the fourth voltage detection point, and detection point 5 is the fifth voltage detection point). By detecting the voltages at multiple voltage detection points, the status of the CC line and the CP line can be accurately determined. When the diagnostic circuit determines that there is a fault in the CC line and / or the CP line, the diagnostic circuit can send a signal to the charging device, thereby disconnecting the power supply circuit and stopping charging the main power circuit.

[0046] The CC circuit includes CC1 and CC2. CC1 is used to implement CC signal information exchange and is mainly used to diagnose the status of CC1 in the present invention. CC2 is an auxiliary diagnostic circuit that can be used to further determine the status of CC1. The diagnostic circuit is provided with an input power supply for providing input voltage. In the present invention, a +12V power supply voltage or a 12V PWM signal input is used. Figure 1 The diagnostic circuit includes a resistor R5 connected to the CC1 line and a resistor R6 connected to the CC2 line.

[0047] Specifically, resistor R5 has one end connected to the input power supply and the other end connected to the CC1 line, serving as a matching resistor for CC1 signal detection. Resistor R6 has one end connected to the CC2 line and the other end connected in series with a switch S7 and then to ground, serving as a matching resistor for CC2 signal detection. A third voltage detection point is located between resistor R5 and the CC1 line, and a fourth voltage detection point is located between resistor R6 and the CC2 line.

[0048] See Figure 1 When the charger is powered on and performs self-test, the CC circuit detection principle is as follows:

[0049] After the charger is awakened, when the CC line is in normal condition, when the switch S7 is disconnected, there is no voltage on the resistor R6. At this time, since the third voltage detection point is connected to the input power supply (12V), the third voltage detection point will detect 12V voltage, and the fourth voltage detection point will detect 0V voltage. When the switch S7 is closed, the resistors R5 and R6 form a path and evenly divide the voltage of the input power supply. At this time, the third voltage detection point and the fourth voltage detection point are connected to the same potential, and their voltage magnitude is .

[0050] At the same time, in this case, three fault states can be determined according to the voltage states of the third voltage detection point and the fourth voltage detection point (there are only three fault states in actual application, and the present invention can accurately identify three faults), namely:

[0051] When the voltages of the third voltage detection point and the fourth voltage detection point are the same and are both 0V before and after the switch S7 is closed, it is determined to be a first fault state: the CC line is shorted to ground;

[0052] In this case, since the voltages at the third and fourth voltage detection points are not affected by the input power supply and are always 0, this indicates that the power supply output voltage has been pulled down to 0 (if the CC line is open, there should be voltage at the third voltage detection point, so this is not a circuit breaker fault). Therefore, it can be determined that the CC line is short-circuited to the vehicle body ground (the first fault state).

[0053] When the voltages at the third voltage detection point and the fourth voltage detection point are the same and both are at the power input voltage before and after the switch S7 is closed, it is determined to be a second fault state: the CC line fault is shorted to the power input (the battery of the electric vehicle, generally 12V);

[0054] In this case, the voltages at the third and fourth voltage detection points are not affected by the input power supply, and their voltages are constant at 12V (power input voltage). It can be seen that in this case, the third and fourth voltage detection points are connected to a voltage input, causing them to be unaffected by the input power supply. Therefore, it can be determined that the CC line is short-circuited and connected to the 12V voltage supply of the entire vehicle (second fault state).

[0055] When the third voltage detection point is at the power input voltage before and after the switch S7 is closed, and the voltage at the fourth voltage detection point is 0V after the switch S7 is closed, it is determined to be a third fault state: a CC line open circuit fault occurs.

[0056] In this case, it can be seen that the voltage at the third voltage detection point is not affected by the voltage divider of resistor R6, so it is constant at the power input voltage. It can be concluded that resistor R6 breaks the circuit at this time, so it can be determined that a circuit break fault has occurred in the CC line (third fault state).

[0057] By detecting the voltages at the third and fourth voltage detection points before and after the switch S7 is closed, various fault problems of the CC line can be accurately identified, greatly improving the safety of the charging line.

[0058] See Figure 2 , the CC line detection principle in the charging state is as follows:

[0059] When the charging gun is inserted, the main power circuit is in the charging state, and when the CC line is in normal condition, the switch S3 of the CC line is in the closed state. At this time, the third voltage detection point and the fourth voltage detection point are at the same potential, and their voltages are the same. .

[0060] At the same time, in this case, four fault states can be determined according to the voltage states of the third voltage detection point and the fourth voltage detection point, namely:

[0061] When the voltages of the third voltage detection point and the fourth voltage detection point are the same and both are 0V, it is determined to be a first fault state: the CC line is shorted to ground;

[0062] In this case, the voltages at the third and fourth voltage detection points are not affected by the input power supply and are always 0, indicating that the power supply output voltage is pulled down to 0. Therefore, it can be determined that the CC line is shorted to ground (the first fault state).

[0063] When the voltages of the third voltage detection point and the fourth voltage detection point are the same and both are the power input voltage, it is determined to be a second fault state: the CC line fault is shorted to the power input;

[0064] In this case, the voltages at the third and fourth voltage detection points are not affected by the input power supply, and the third and fourth voltage detection points are electrically connected to a constant voltage input. Therefore, it can be determined that the CC line is short-circuited and connected to the 12V voltage supply of the entire vehicle (second fault state).

[0065] When the voltage at the third voltage detection point is the power input voltage and the voltage at the fourth voltage detection point is 0V, it is determined to be a fourth fault state: a circuit breaker fault occurs in the CC1 line;

[0066] In this case, since the voltage at the third voltage detection point is 12V (voltage input voltage), it indicates that it is not affected by the voltage divider of resistor R6 and resistor RC in the charging gun. It can be seen that the CC1 line is disconnected from resistor R6 and resistor RC, that is, it can be determined that a circuit breaker fault has occurred in the CC1 line (fourth fault state).

[0067] When the voltage at the third voltage detection point remains unchanged and the voltage at the fourth voltage detection point drops to 0V, it is determined to be a fifth fault state: a circuit breaker fault occurs in the CC2 line.

[0068] In this case, the voltage at the third voltage detection point still maintains the normal voltage, indicating that the resistor RC in the charging gun plays a voltage divider role and divides the resistor R5, indicating that the CC1 line is normal at this time. At the same time, the voltage at the fourth voltage detection point becomes 0, indicating that it does not receive the voltage input voltage, so it can be determined that there is a circuit breaker fault in the CC2 line (the fifth fault state).

[0069] The third fault state is determined during the diagnostic circuit's power-on self-test, which only confirms a CC line open fault, but cannot determine whether the fault is in CC1 or CC2. The fourth and fifth fault states are determined during charging, and can accurately identify whether the fault is in CC1 or CC2.

[0070] When the charging gun is inserted and the charging state is entered, the fault problem on the CC line can be accurately determined by detecting the voltage changes at the third voltage detection point and the fourth voltage detection point, further improving the safety of the charger.

[0071] When the CC line is determined to be in an abnormal state, the charger can promptly report it to the vehicle controller for processing and disconnect the charging state to avoid subsequent problems.

[0072] See Figure 1 The CP circuit includes CP1 and CP2, as well as resistors R1 and R3 connected to them. Similar to the CC circuit, CP1 serves as the primary detection circuit, while CP2 is used for auxiliary detection to further confirm the status of CP1.

[0073] Specifically, resistor R1 has one end connected to the CP1 circuit, and the other end connected in series with switch S2 and then to ground. Resistor R2 and switch S4 are connected in parallel between resistor R1 and switch S2. Resistor R3 has one end connected to the CP2 circuit, and the other end connected in series with switch S6 and then to ground. Switches S2 and S4 are CP switching switches as required by national standards. Resistors R1 and R2 serve as matching resistors for CP1 signal detection, and resistor R3 serves as a matching resistor for CP2 signal detection. The diagnostic circuit also includes switch S5, one end of which is connected between the CP1 circuit and resistor R1, and the other end is connected to the input power supply (12V). Together with switches S6 and S7, it forms a logic switch for CC / CP signals. Diodes are also provided in the CP1 and CP2 circuits, primarily for protection. A second voltage detection point is set between resistor R1 and the CP1 circuit, and a fifth voltage detection point is set between resistor R3 and the CP2 circuit.

[0074] See Figure 1 After the charger is awakened, switches S2 and S6 are closed. When the CP line is in a normal state, before the logic switch S5 is closed, the CP line is not connected to the input power supply. At this time, the voltages at the second and fifth voltage detection points are both 0V. When switch S5 is closed, ignoring the effect of the diode conduction voltage drop on the CP1 and CP2 lines, the second and fifth voltage detection points are both connected to the input power supply and are at the same potential, both 12V.

[0075] At the same time, in this case, three fault states can be determined according to the voltage states of the second voltage detection point and the fifth voltage detection point (there are only three fault states in actual application, and the present invention can accurately detect the three fault states), namely:

[0076] When the voltages of the second voltage detection point and the fifth voltage detection point are the same and are both 0V before and after the switch S5 is closed, it is determined to be a sixth fault state: the CP line is shorted to ground;

[0077] In this case, since the second and fifth voltage detection points are connected to the input power supply, and their voltage is always 0 when the switch S5 is closed, it can be seen that the voltages on the second and fifth voltage detection points are pulled down to 0, that is, the second and fifth voltage detection points are connected to the ground, so it can be determined that the CP line fault is shorted to the vehicle body ground (sixth fault state).

[0078] When the voltages of the second voltage detection point and the fifth voltage detection point are the same and both are the power input voltage before and after the switch S5 is closed, it is determined to be a seventh fault state: the CP line is shorted to the power input;

[0079] In this case, since voltage exists at the second and fifth voltage detection points before switch S5 is closed, it can be determined that the CP line provides a voltage input. Since its voltage is constant at 12V, it can be determined that the CP line fault is shorted to the 12V voltage supply of the entire vehicle (the seventh fault state).

[0080] When the voltages at the second voltage detection point and the fifth voltage detection point are both 0 V before the switch S5 is closed, and after the switch S5 is closed, the voltage at the second voltage detection point becomes the power supply input voltage, and the voltage at the fifth voltage detection point is still 0 V, it is determined to be an eighth fault state: a circuit breaker fault occurs in the CP line.

[0081] In this case, since the voltage at the second voltage detection point is affected by the switch S5, it can be determined that the CP line is not shorted to ground. The voltage at the fifth voltage detection point is constantly 0, indicating that the power input voltage is not transmitted to the fifth voltage detection point. Since the input voltage does not need to pass through the CP line to be transmitted to the second voltage detection point, it can be determined that the fault is in the CP line. Since the voltage at the fifth voltage detection point is 0, it can be determined that a circuit breaker fault has occurred in the CP line (the eighth fault state).

[0082] By measuring the voltage changes at the second voltage detection point and the fifth voltage detection point before and after the switch S5 is closed, fault information of the CP circuit can be accurately identified, thereby improving the safety of the charging circuit.

[0083] See Figure 2, the CP line detection principle in the charging state is as follows:

[0084] When the charging gun is inserted and the main power circuit is in the charging state, under normal conditions, the diagnostic logic switches S5 and S6 are disconnected, and switches S1, S2 and S4 are closed. At this time, the circuit is powered by the charging pile. Since the resistor R2 is connected in parallel with the resistor R1 and in series with the 1K resistor in the charging pile, the second voltage detection point and the fifth voltage detection point are set between the resistor R2 and the 1K resistor, and the voltage is the voltage after voltage division. Here, the resistor R1 is 1.3K ohms and the resistor R2 is 3.01K ohms. After voltage division with the 1K resistor, the voltage of the second voltage detection point and the fifth voltage detection point is 6V, that is, under normal circumstances, the voltage of the second voltage detection point and the fifth voltage detection point is 6V.

[0085] Among them, a first voltage detection point is set in the charging pile, which is set at the output port of the charging pile for detecting the status of the charging pile. When the voltage of the first voltage detection point is 0, it means that there is a fault in the charging pile. When the voltage of the first voltage detection point is 12V, it means that the charging pile is normal.

[0086] When the charging pile is normal, four fault states can be determined based on the voltage status of the second voltage detection point and the fifth voltage detection point, namely:

[0087] When the voltages of the second voltage detection point and the fifth voltage detection point are the same and both are 0V, it is determined to be a sixth fault state: the CP line is shorted to ground;

[0088] In this case, since the voltages at the second and fifth voltage detection points are constantly 0, it indicates that the output voltage of the charging pile is pulled down, that is, the second and fifth voltage detection points are connected to the ground, so it can be determined that the CP line fault is shorted to the ground (sixth fault state).

[0089] When the voltages of the second voltage detection point and the fifth voltage detection point are the same and both are the power input voltage, it is determined to be a seventh fault state: the CP line fault is shorted to the power input;

[0090] In this case, since there is voltage at the second voltage detection point and the fifth voltage detection point, it indicates that the CP line does not have a circuit breaker fault, and its voltage is constant at 12V, indicating that the voltage at the second voltage detection point and the fifth voltage detection point is not affected by the voltage divider of the 1K resistor on the charging pile, that is, it is connected to the power supply. Therefore, it can be determined that the CP line fault is disconnected and connected to the power input, that is, 12V power supply (seventh fault state).

[0091] When the voltage at the second voltage detection point is 0V and the voltage at the fifth voltage detection point is the power input voltage, it is determined to be a ninth fault state: a circuit breaker fault occurs in the CP1 line;

[0092] In this case, since the voltage at the second voltage detection point is 0, it indicates that the CP line has a circuit breaker fault, but since the voltage at the fifth voltage detection point is 12V, it indicates that the CP2 line is normal. Therefore, it can be determined that the CP1 line has a circuit breaker fault (ninth fault state).

[0093] When the voltage at the second voltage detection point remains unchanged and the voltage at the fifth voltage detection point drops to 0V, it is determined to be a tenth fault state: a circuit breaker fault occurs on the CP2 line.

[0094] In this case, since the voltage at the second voltage detection point remains unchanged and remains at the normal voltage of 6V, it indicates that the CP1 line is not broken. The voltage at the fifth voltage detection point is 0, indicating that the fifth voltage detection point does not receive any input voltage. Therefore, it can be determined that a circuit breaker fault has occurred in the CP2 line (the tenth fault state).

[0095] Similar to the CC line detection principle, the eighth fault state is determined during the CP line power-on self-test. It can only determine that a circuit breaker fault has occurred on the CP line, but cannot determine whether the fault is on the CP1 line or the CP2 line. The ninth and tenth fault states are used for fault detection in the charging state, and can accurately identify faults on the CP1 line and the CP2 line.

[0096] Those skilled in the art can first determine the faults of the CC and CP lines through the self-test mode. If the specific fault cannot be accurately determined in the self-test mode, the charging gun can be inserted to detect the specific faults of the CC and CP lines.

[0097] See Figure 2 L1, L2, and L3 are live wires, and N is the neutral wire. It serves as the power supply circuit for the main power circuit. Multiple switches are provided between the power supply circuit and the main power circuit. When the CC / CP diagnostic circuit determines that there is a fault in the CC line and / or the CP line, the charger can detect the abnormal state in time and report it to the vehicle controller. At this time, the multiple switches between the power supply circuit and the main power circuit are disconnected, and power supply to the main power circuit is stopped.

[0098] The CC / CP diagnostic circuit proposed in the present invention can perform power-on self-tests when the charging gun is not plugged in and test the CC and CP lines when the charging gun is plugged in. Furthermore, for each fault state, the voltage at each voltage detection point is different. The specific fault can be accurately determined based on the specific voltage state of each voltage detection point. This allows users to perform repairs based on the specific fault, greatly improving the safety of the charger.

[0099] The present invention further provides a charger, which starts charging when the charger completes interactive connection with the CC signal and CP signal of the charging pile through the CC line and the CP line;

[0100] When at least one of the CC line and the CP line fails, the charger stops the charging mode;

[0101] The charger uses the CC / CP diagnostic circuit to diagnose faults of the CC line and the CP line.

[0102] Compared with the prior art, the present invention can accurately identify circuit faults, avoid erroneous information interaction between the charger and the charging pile, and effectively improve the safety of the charger.

[0103] The above embodiments are only used to illustrate the specific implementation methods of the present invention. It should be pointed out that for ordinary technicians in this field, several modifications and changes can be made without departing from the concept of the present invention. These modifications and changes should all fall within the scope of protection of the present invention.

Claims

1. A CC / CP diagnostic circuit, comprising a main power circuit and a power supply circuit connected to the main power circuit, characterized in that: The system further includes a diagnostic circuit connected to the CC line and the CP line, wherein the diagnostic circuit includes a plurality of voltage detection points and determines a fault state of the CC line and / or the CP line by detecting voltages at the voltage detection points; The diagnostic circuit includes resistors R5 and R6 connected to the CC line, and a third voltage detection point and a fourth voltage detection point provided between the resistors R5 and R6 and the CC line. When the voltage at the third voltage detection point and / or the fourth voltage detection point is abnormal, the CC line is faulty. The diagnostic circuit includes 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. When the voltage at the second voltage detection point and / or the fifth voltage detection point is abnormal, the CP line is faulty. The CP circuit includes a CP1 circuit and a CP2 circuit. One end of the resistor R1 is connected to the CP1 circuit, and the other end is connected in series with a switch S2 and then connected to ground. The diagnostic circuit also includes a resistor R2 and a switch S4 connected in parallel to the resistor R1 and the switch S2. The resistor R2 is used to divide the voltage after being connected in parallel with the resistor R1. One end of the resistor R3 is connected to the CP2 circuit, and the other end is connected in series with a switch S6 and then connected to ground. The second voltage detection point is set between the resistor R1 and the CP1 circuit, and the fifth voltage detection point is set between the resistor R3 and the CP2 circuit; A switch S5 is further connected between the second voltage detection point and the CP1 line. 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 the power input.

2. The CC / CP diagnostic circuit according to claim 1, characterized in that: The CC circuit includes a CC1 circuit and a CC2 circuit connected to each other. One end of the resistor R5 is connected to the CC1 circuit and the other end is connected to the power input. One end of the resistor R6 is connected to the CC2 circuit and the other end is connected to the ground after being connected in series with a switch S7. The third voltage detection point is located between the resistor R5 and the CC1 circuit, and the fourth voltage detection point is located between the resistor R6 and the CC2 circuit.

3. The CC / CP diagnostic circuit according to claim 2, characterized in that: When the charger is powered on and self-tested, there are three fault states determined according to the voltage states of the third voltage detection point and the fourth voltage detection point, which are: When the voltages of the third voltage detection point and the fourth voltage detection point are the same and are both 0V before and after the switch S7 is closed, it is determined to be a first fault state: the CC line is shorted to ground; When the voltages at the third voltage detection point and the fourth voltage detection point are the same and both are the power input voltage before and after the switch S7 is closed, it is determined to be a second fault state: the CC line is shorted to the power input; When the third voltage detection point is at the power input voltage before and after the switch S7 is closed, and the voltage at the fourth voltage detection point is 0V after the switch S7 is closed, it is determined to be a third fault state: a CC line open circuit fault occurs.

4. The CC / CP diagnostic circuit according to claim 2, characterized in that: When the main power circuit is in a charging state, there are four fault states determined according to the voltage states of the third voltage detection point and the fourth voltage detection point, namely: When the voltages of the third voltage detection point and the fourth voltage detection point are the same and both are 0V, it is determined to be a first fault state: the CC line is shorted to ground; When the voltages of the third voltage detection point and the fourth voltage detection point are the same and both are the power input voltage, it is determined to be a second fault state: the CC line fault is shorted to the power input; When the voltage at the third voltage detection point is the power input voltage and the voltage at the fourth voltage detection point is 0V, it is determined to be a fourth fault state: a circuit breaker fault occurs in the CC1 line; When the voltage at the third voltage detection point remains unchanged and the voltage at the fourth voltage detection point drops to 0V, it is determined to be a fifth fault state: a circuit breaker fault occurs in the CC2 line.

5. The CC / CP diagnostic circuit according to claim 1, characterized in that: When the charger is powered on and self-tested, there are three fault states determined according to the voltage states of the second voltage detection point and the fifth voltage detection point, which are: When the voltages of the second voltage detection point and the fifth voltage detection point are the same and are both 0V before and after the switch S5 is closed, it is determined to be a sixth fault state: the CP line is shorted to ground; When the voltages of the second voltage detection point and the fifth voltage detection point are the same and both are the power input voltage before and after the switch S5 is closed, it is determined to be a seventh fault state: the CP line is shorted to the power input; When the voltages at the second voltage detection point and the fifth voltage detection point are both 0 V before the switch S5 is closed, and after the switch S5 is closed, the voltage at the second voltage detection point becomes the power supply input voltage, and the voltage at the fifth voltage detection point is still 0 V, it is determined to be an eighth fault state: a circuit breaker fault occurs in the CP line.

6. The CC / CP diagnostic circuit according to claim 5, characterized in that: When the main power circuit is in a charging state, there are four fault states determined according to the voltage states of the second voltage detection point and the fifth voltage detection point, namely: When the voltages of the second voltage detection point and the fifth voltage detection point are the same and both are 0V, it is determined to be a sixth fault state: the CP line is shorted to ground; When the voltages of the second voltage detection point and the fifth voltage detection point are the same and both are the power input voltage, it is determined to be a seventh fault state: the CP line fault is shorted to the power input; When the voltage at the second voltage detection point is 0V and the voltage at the fifth voltage detection point is the power input voltage, it is determined to be a ninth fault state: a circuit breaker fault occurs in the CP1 line; When the voltage at the second voltage detection point remains unchanged and the voltage at the fifth voltage detection point drops to 0V, it is determined to be a tenth fault state: a circuit breaker fault occurs on the CP2 line.

7. A charger, characterized in that: When the charger completes the interactive connection of CC signal and CP signal with the charging pile through CC line and CP line, the charger starts charging; When at least one of the CC line and the CP line fails, the charger stops the charging mode; The charger uses the CC / CP diagnostic circuit according to any one of claims 1 to 6 to diagnose faults of the CC line and the CP line.

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