Alternating current charging gun and pile vehicle end diode detection circuit

Abstract

The invention provides an alternating-current charging gun and pile vehicle end diode detection circuit, and belongs to the technical field of electric vehicle charging, the alternating-current charging gun and pile vehicle end diode detection circuit comprises a Q8 and a Q10, a base electrode of the Q8 is connected to a-12V power supply through a driving resistor R70, an R90 is connected between the base electrode of the Q8 and a CP, an R91 is connected between an emitting electrode of the Q8 and a CP signal, a base electrode of the Q10 is connected to a collector electrode of the Q8 through a driving resistor R92, and the Q10 is connected to the-12V power supply. An R71 is connected between the collector electrode of the Q10 and the 5V power supply, the collector electrode of the Q10 is connected to the IO port of the MCU, and the emitter electrode of the Q10 is connected with the GND. The method improves the detection reliability, has a clear fault judgment mechanism, is suitable for a standard charging communication protocol, and is simple in circuit structure and high in integration degree.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of electric vehicle charging, and particularly relates to an alternating current charging gun and pile truck end diode detection circuit. BACKGROUND

[0002] GB / T 18487.1-2023 is "Electric Vehicle Conduction Charging System Part 1: General Requirements", covering the technical requirements of electric vehicles, charging piles and charging facilities, including rated voltage, power, interface, communication protocol, etc.

[0003] A.2.6 in GB / T 18487.1-2023 clearly states: "Before energy transmission, the power supply device should be able to verify that the connection is an electric vehicle or a non-load device by detecting the presence of diode D1 on the control guide circuit; the detection should be carried out at least once from state X (X=1, 2, 3, defined in Table A.4) to state X' or during state X' before the power supply device turns on the AC power supply circuit; when the low state of the PWM signal is detected within the voltage range specified in Table A.4, it is determined that there is a diode D1 on the control guide circuit and the connection is an electric vehicle or an electric vehicle simulator; however, in the existing diode detection circuit, a detection chip is usually provided, and the detection circuit is relatively complex, so it is easy to be disturbed and the detection reliability is low, and it is not convenient to judge the fault. SUMMARY

[0004] The application provides an alternating current charging gun and pile truck end diode detection circuit, which improves the detection reliability, has a clear fault judgment mechanism, is suitable for standard charging communication protocol, has a simple circuit structure and high integration degree.

[0005] The application is realized by the following technical solutions:

[0006] An alternating current charging gun and pile truck end diode detection circuit, comprising Q8 and Q10, wherein the base of Q8 is connected to a -12V power supply through a drive resistor R70, R90 is connected between the base of Q8 and CP, R91 is connected between the emitter of Q8 and CP signal, the base of Q10 is connected to the collector of Q8 through a drive resistor R92, R71 is connected between the collector of Q10 and a 5V power supply, the collector of Q10 is connected to the IO port of MCU, and the emitter of Q10 is connected to GND.

[0007] Preferably, R90 is a pull-up resistor, R91 is a current limiting resistor, and R17 is a pull-up resistor.

[0008] Preferably, Q8 is a PNP triode, and Q10 is an NPN triode.

[0009] Compared with the prior art, the application has the beneficial effects of:

[0010] 1. High reliability detection: By judging whether the MCU node signal is a PWM waveform or a fixed low level, the normal and fault states of the diode can be clearly distinguished, the detection logic is clear, the misjudgment rate is low, and the uncertainty caused by ambiguous judgment of analog level is effectively avoided.

[0011] 2. Simple circuit structure and low cost: Only common discrete devices such as PNP and NPN triodes, resistors, etc. are used, without the need for special detection chips or complex circuits, which is conducive to reducing system cost and improving circuit reliability, and is easy to popularize and apply.

[0012] 3. Adapt to standard charging communication protocol: The detection process is compatible with the standard PWM state of the charging pile CP signal, does not interfere with the original communication process, and realizes non-intrusive diagnosis in the normal interaction process of the charging pile-vehicle.

[0013] 4. Clear fault judgment mechanism: When the vehicle-side diode fails or is short-circuited, the circuit output changes from a PWM signal to a fixed low level, which is obvious and easy for the MCU to make fast and accurate digital logic judgments without complex AD sampling or software analysis.

[0014] 5. Strong anti-interference: The CP signal is used to drive the triode switch in different voltage characteristics in the positive and negative half cycles, and the circuit can still work stably in an electrical noise environment, and the detection result is less affected by line voltage drop and fluctuation.

[0015] 6. Easy to integrate and implement: The circuit structure is simple and can be directly compatible with the existing charging control panel MCU interface without additional complex isolation or conditioning circuits, which is easy to integrate quickly in the existing charging pile system. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 is the circuit diagram of the vehicle-side diode detection circuit of the application for D1.

[0017] Figure 2 is the circuit diagram of the control guide circuit of the application.

[0018] Figure 3 is the voltage of the detection point 1 of the application and the corresponding charging process state table. DETAILED DESCRIPTION

[0019] The application is specifically described below in combination with the drawings. As shown in Figure 1, an alternating current charging gun, a pile car end diode detection circuit includes Q8 and Q10, wherein the base of Q8 is connected to a -12V power supply through a drive resistor R70, R90 is connected between the base of Q8 and CP, R91 is connected between the emitter of Q8 and the CP signal, the base of Q10 is connected to the collector of Q8 through a drive resistor R92, R71 is connected between the collector of Q10 and a 5V power supply, the collector of Q10 is connected to the IO port of an MCU, the IO port of the MCU realizes the detection function of the car end diode by using the EV_DIODE_CHK_MCU node signal, the CP signal is controlled and feedback is detected to determine whether the diode state is normal, and the emitter of Q10 is connected to GND.

[0020] In the embodiment, specifically, R90 is a pull-up resistor, R91 is a current limiting resistor, and R17 is a pull-up resistor, one end of which is connected to a 5V power supply.

[0021] In the embodiment, specifically, Q8 is a PNP triode, and Q10 is an NPN triode.

[0022] In the embodiment, in combination with the drawings Figure 2 As shown in Figure 2, C1 and C2 are internal alternating current contactors / relays of a power supply device; S1 is an internal PWM signal switching switch of the power supply device; R1 is an internal control guide circuit resistor of the power supply device; R3 is an internal normally closed switch of a vehicle plug; R4 and RC are internal control guide circuit resistors of the vehicle plug; S2 is an internal control guide circuit switch of the vehicle; R2 and R3 are internal control guide circuit resistors of the vehicle; and D1 is an internal control guide circuit diode of the vehicle.

[0023] In the embodiment, in combination with the drawings Figure 3 As shown in Figure 3, the voltage of detection point 1 and the corresponding charging process state table give the voltage of detection point 1 and the corresponding charging process state, and the measurement error of the power supply device is also considered. There is no undefined detection point 1 voltage range between the charging process states. If the detection point 1 voltage state is within the numerical range specified in Table A.4, it is a valid state.

[0024] Working principle

[0025] In the application, when the charging pile / gun is in state 2, the car end diode D1 is detected: in this state, the positive half-axis voltage of detection point 1 (i.e. the positive half-axis of the CP signal) is 9V;

[0026] If the car end diode D1 normally exists, the negative half-axis voltage of the CP signal is -12V, and due to the blocking effect of D1, the negative voltage cannot form a voltage divider through D1 and the car end resistor R3, and the CP signal shows a PWM waveform in state 2 with an amplitude of +9V and -12V alternately:

[0027] When the CP signal voltage is +9V, Q8 is saturated and turned on, providing base current for Q10 through driving resistor R92, making Q10 turned on, and the EV_DIODE_CHK_MCU node signal is pulled down to 0.3V; when the CP signal voltage is -12V, Q8 is turned off, and Q10 is turned off accordingly, and the EV_DIODE_CHK_MCU node signal is pulled up to 5V by pull-up resistor R17; therefore, the EV_DIODE_CHK_MCU node signal outputs a PWM signal alternated between 5V and 0.3V;

[0028] If the vehicle-end diode D1 is absent or short-circuited, in state 2:

[0029] The CP signal positive half-axis voltage is still +9V, and the negative half-axis voltage is about -9V due to the absence of D1 and the voltage division by vehicle-end resistor R3, and the CP signal exhibits a PWM waveform between +9V and -9V; at this time, no matter whether the CP signal voltage is +9V or -9V, Q8 is saturated and turned on, causing Q10 to be continuously turned on, and the EV_DIODE_CHK_MCU node signal is stably pulled down to 0.3V, exhibiting a direct-current low level.

[0030] By judging the output of the EV_DIODE_CHK_MCU node signal as a PWM waveform or a fixed low level, the MCU can accurately diagnose whether the vehicle-end diode is normal.

[0031] The technical solutions described in the present application or inspired by the technical solutions of the present application by those skilled in the art to design similar technical solutions to achieve the above technical effects are all within the protection scope of the present application.

Claims

1. An alternating current charging gun, pole car end diode detection circuit, characterized in that, Q8 and Q10 are included, wherein the base of Q8 is connected to -12V power supply through driving resistor R70, R90 is connected between the base of Q8 and CP, R91 is connected between the emitter of Q8 and CP signal, the base of Q10 is connected to the collector of Q8 through driving resistor R92, R71 is connected between the collector of Q10 and 5V power supply, the collector of Q10 is connected to IO port of MCU, and the emitter of Q10 is connected to GND.

2. The AC charging gun, pit car diode detection circuit of claim 1, wherein, R90 is a pull-up resistor, R91 is a current-limiting resistor, and R17 is a pull-up resistor.

3. The AC charging gun, pit car diode detection circuit of claim 1, wherein, Q8 is a PNP triode, and Q10 is an NPN triode.

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