Relay adhesion redundancy detection system and method for new energy automobile power system

Abstract

The invention discloses a relay adhesion redundancy detection system and method for a new energy automobile power system, and belongs to the technical field of automobile electronics. The system comprises a battery monitoring chip and a controller which are connected with each other, the battery monitoring chip comprises a relay self-checking circuit and a voltage sampling circuit, and the relay self-checking circuit is connected to the two ends of a main positive relay, the two ends of a main negative relay and the two ends of a pre-charging relay in parallel; the voltage sampling circuits are respectively connected between the rear end of the main positive relay and the front end of the main negative relay and between the rear end of the main positive relay and the rear end of the main negative relay; and the controller is respectively connected with the relay self-checking circuit and the voltage sampling circuit and is used for carrying out relay adhesion redundancy detection according to the acquired voltage signal. According to the invention, through a redundancy design mode, the relay is self-detected, and the cross voltage sampling judgment is carried out, so that the relay adhesion detection efficiency is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of automobile electronics, and in particular, relates to a relay adhesion redundancy detection system and method for a new energy automobile power system. Background Art

[0002] Among the existing detection technologies, only the voltage sampling detection function is used to determine whether the relay is stuck. When the high-voltage detection circuit itself fails, it is impossible to detect whether the relay is stuck, which makes it difficult to troubleshoot the problem. In addition, the position of automotive parts on the vehicle is difficult to disassemble, which is very inconvenient to quickly locate and troubleshoot the fault on site, because the relay is placed in the battery pack, and the battery pack needs to be disassembled to analyze the fault.

[0003] At present, the integration of automotive electronics is getting higher and higher, developing rapidly, and the market size is constantly expanding; with the continuous upgrading of the battery pack voltage platform, the fault location detection of relay adhesion has also emerged and the demand has become more and more urgent; because automotive electronics are different from industrial electronic equipment, they have very high requirements for safety and integration, and it is necessary to report the risk of relay adhesion and abnormal adhesion in a timely manner. In addition, since the main and negative relays are not easy to disassemble in the car, fault location and analysis are difficult, and a large number of automotive parts need to be disassembled before the electronic equipment can be taken out for further analysis.

[0004] To this end, the present application proposes a relay adhesion redundancy detection system and method for a new energy vehicle power system. Summary of the invention

[0005] The present invention aims to overcome the deficiencies of the prior art and proposes a relay adhesion redundant detection system and method for a new energy vehicle power system to achieve the following objectives: through a redundant design, both self-inspection of the relay and judgment of cross voltage sampling are performed, thereby improving the efficiency of relay adhesion detection.

[0006] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a relay adhesion redundancy detection system for a new energy vehicle power system, the system includes a power battery positive electrode, a main positive relay, a load, a main negative relay, and a power battery negative electrode in sequence, and at the same time, the pre-charge relay and the pre-charge resistor are connected in series in parallel at both ends of the main positive relay, and the load capacitor is connected in parallel at both ends of the load. The system also includes: a battery monitoring chip and a controller connected to each other, and the battery monitoring chip includes multiple relay self-test circuits and multiple voltage sampling circuits, wherein:

[0007] The multiple relay self-test circuits are respectively connected in parallel at both ends of the main positive relay, the main negative relay, and the pre-charge relay; the multiple voltage sampling circuits are respectively connected between the rear end LINK+ of the main positive relay and the front end PACK- of the main negative relay, and between the rear end LINK+ of the main positive relay and the rear end LINK- of the main negative relay; the controller is respectively connected to the relay self-test circuit and the voltage sampling circuit, and is used to perform relay adhesion redundancy detection according to the collected voltage signals.

[0008] Preferably, the relay self-test circuit includes: bypass capacitors C1 and C2, resistor R1, resistor R2, resistor R3, resistor R4, resistor R5, optocoupler U1, and diode D3;

[0009] Wherein: the LED cathode of the optocoupler U1, the resistor R5, the resistor R4, and the LED anode of the optocoupler U1 are connected in series in sequence to form a loop, the lead terminal between the resistor R5 and the resistor R4 is connected to the power supply voltage V2, and the lead terminal between the LED cathode of the optocoupler U1 and the resistor R5 is connected to the first enable signal of the controller;

[0010] The power supply voltage V1 is connected to the collector of the optocoupler U1 through resistors R2 and R3 connected in series in sequence, the emitter of the optocoupler U1 is connected to the anode of the diode, and the cathode of the diode is connected to the rear end of the relay to be tested; the lead terminals between the resistors R2 and R3 are respectively connected to the front end of the relay to be tested, and are connected to the first sampling terminal AD of the controller through the resistor R1; the bypass capacitors C1 and C2 are connected in parallel between the first sampling terminal AD and the front end of the relay to be tested.

[0011] Preferably, a capacitor C3 is connected in parallel between the first sampling terminal AD and the front end of the relay to be tested, and the capacitor C3 and the resistor R1 form an RC low-pass filter circuit.

[0012] Preferably, the relay self-test circuit also includes Zener diodes D1 and D2, wherein: the terminals extending between the resistors R2 and R3 are respectively connected to the front end of the relay to be tested through the reverse-connected Zener diode D2, and are connected to the power supply voltage V1 through the forward-connected Zener diode D1.

[0013] Preferably, the power supply voltage V1 is provided by the battery monitoring chip; and the power supply voltage V2 is provided by the vehicle low-voltage power supply.

[0014] Preferably, in the voltage sampling circuit, the base of the transistor Q1 is connected to the second enable terminal CTRL1 of the controller, the emitter of the transistor Q1 is grounded, the collector of the transistor Q1 is connected to the LED cathode of the optocoupler U2, and the LED anode of the optocoupler U2 is connected to the power supply voltage VCC through the resistor R6;

[0015] The first input terminal of the voltage sampling circuit is connected to the collector of the optocoupler U2 through resistors R7, R8, and R9 connected in series in sequence, and the emitter of the optocoupler U2 is connected to the second input terminal of the voltage sampling circuit through resistors R10 and R11 connected in series in sequence; the lead terminal between the resistor R10 and the resistor R11 is connected to the second sampling terminal AD1 of the controller.

[0016] At the same time, the application also proposes a relay adhesion redundancy detection method for a new energy vehicle power system based on the above system, and the method includes the following steps:

[0017] Step S1, the vehicle power system is initialized. After the initialization is completed, the main positive relay, the main negative relay, and the pre-charge relay are all in the disconnected state;

[0018] Step S2, the controller enables the relay self-check circuits connected in parallel at both ends of the main positive relay, the main negative relay, and the pre-charge relay to determine whether the main positive relay, the main negative relay, and the pre-charge relay are adhered; if no adhesion occurs, proceed to the next step;

[0019] Step S3, during the process of pre-charging and powering off the whole vehicle, the controller enables the voltage acquisition circuit connected between the rear end LINK+ of the main positive relay and the front end PACK- of the main negative relay to obtain the first sampling voltage, and the voltage acquisition circuit between the rear end LINK+ of the main positive relay and the rear end LINK- of the main negative relay to obtain the second sampling voltage, and further determines whether the main positive relay, the pre-charging relay and the main negative relay are adhered according to the first sampling voltage and the second sampling voltage; when adhesion is found, the detection is stopped immediately and the fault is reported.

[0020] Preferably, in step S2, when the voltage collected by the first sampling terminal AD of the controller is equal to the power supply voltage V1, it indicates that the relay to be tested is not stuck; when the voltage collected by the first sampling terminal AD of the controller is equal to the divided voltage across the resistor R3 and the diode D3, it indicates that the relay to be tested is stuck.

[0021] Preferably, step S3 comprises:

[0022] Step S31, when the main positive relay, the main negative relay, and the pre-charge relay are all in the disconnected state, the controller enables the voltage acquisition circuit connected between the rear end LINK+ of the main positive relay and the front end PACK- of the main negative relay to obtain the first sampling voltage. When the first sampling voltage is not 0, it is judged that the main positive relay is adhered, and the detection is immediately stopped and the fault is reported; when the main positive relay is not adhered, proceed to the next step;

[0023] Step S32, close the pre-charge relay, and the controller enables the voltage acquisition circuit connected between the rear end LINK+ of the main positive relay and the rear end LINK- of the main negative relay to obtain a second sampling voltage. If it is detected that the second sampling voltage is not 0 and rises rapidly, it is determined that the main negative relay is adhered, and the detection is immediately stopped and the fault is reported; when the main negative relay is not adhered, proceed to the next step;

[0024] Step S33, close the main negative relay, and disconnect the pre-charging relay after the pre-charging is completed, and close the main positive relay at the same time to complete the power-on detection;

[0025] Step S34, when power is off, disconnect the main positive relay. If the controller enables the voltage acquisition circuit connected between the rear end LINK+ of the main positive relay and the front end PACK- of the main negative relay to obtain the first sampling voltage, when the first sampling voltage is not 0 and lasts for a preset time, it is judged that the pre-charge relay is stuck. At this time, the detection is stopped immediately and the fault is reported.

[0026] Preferably, step S3 also includes: before step S32, the controller enables the voltage acquisition circuit connected between the rear end LINK+ of the main positive relay and the rear end LINK- of the main negative relay to obtain a second sampling voltage. If the second sampling voltage is 0, the next step is directly executed; if the second sampling voltage is not 0, indicating that the load capacitor is not fully discharged, then the next step is continued when the second sampling voltage is 0.

[0027] The technical effect of the present invention is as follows: the present invention uses a redundant design to preliminarily determine whether the relay is stuck based on the voltage collected by the relay self-test circuit, and then further determine whether the relay is stuck based on the voltage cross-collected by the voltage sampling circuit, thereby forming a redundant detection. Only when both determine that no adhesion occurs, the adhesion detection is considered to have passed, thereby improving the efficiency of the relay adhesion detection. In this way, the relay adhesion fault can be discovered in time before the vehicle officially starts pre-charging and powering up, ensuring that the battery system can carry out the pre-charging and powering-up process normally.

[0028] In addition, the system of the present application has a simple structure, is easy to operate, is easy to install, has low cost, and can be widely used. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a partial schematic diagram of a relay adhesion redundancy detection system of a new energy vehicle power system according to an embodiment of the present invention;

[0030] Figure 2 This is an overall structural block diagram of a relay adhesion redundancy detection system for a new energy vehicle power system according to an embodiment of the present invention;

[0031] Figure 3A relay self-test circuit diagram of an embodiment of the present invention;

[0032] Figure 4 4 is a voltage sampling circuit diagram of an embodiment of the present invention. DETAILED DESCRIPTION

[0033] The following is a further detailed description of the specific implementation of the present invention through the description of the embodiments with reference to the accompanying drawings, the purpose of which is to help those skilled in the art have a more complete, accurate and in-depth understanding of the inventive concept and technical solution of the present invention, and to facilitate its implementation. It should be noted that the words "first", "second" and the like described in this application are only for the convenience of describing the technical solution to distinguish different components, and are not used to limit this application. In order to make the technical solution of the present invention clearer, the present invention is explained through the following embodiments.

[0034] This embodiment discloses a relay adhesion redundancy detection system for a new energy vehicle power system. Figure 1 and Figure 2 As shown, the system includes the positive electrode of the power battery, the main positive relay, the load, the main negative relay, and the negative electrode of the power battery in sequence. At the same time, the pre-charge relay and the pre-charge resistor are connected in series and connected in parallel at both ends of the main positive relay. The load is connected in parallel with a load capacitor at both ends of the load. At the same time, the system also includes: a battery monitoring chip and a controller connected to each other. The battery monitoring chip includes multiple relay self-test circuits and multiple voltage sampling circuits, wherein:

[0035] The multiple relay self-test circuits are respectively connected in parallel at both ends of the main positive relay, the main negative relay, and the pre-charge relay; the multiple voltage sampling circuits are respectively connected between the rear end LINK+ of the main positive relay and the front end PACK- of the main negative relay, and between the rear end LINK+ of the main positive relay and the rear end LINK- of the main negative relay; the controller is respectively connected to the relay self-test circuit and the voltage sampling circuit, and is used to perform relay adhesion redundant detection according to the collected voltage signal, that is, to preliminarily judge whether the relay is adhered according to the voltage collected by the relay self-test circuit, and then to further judge whether the relay is adhered according to the voltage collected by the voltage sampling circuit, thereby forming redundant detection. Only when both judge that no adhesion occurs, is it regarded as passing the adhesion detection.

[0036] In this embodiment, the battery monitoring chip can use BMS (battery management system), support a variety of peripheral circuit expansion, and can meet the needs of all-round battery supervision. The controller of this embodiment can use a single-chip microcomputer, MCU, etc., which has the advantages of small size, high integration, and low cost, and can realize fast and accurate data processing.

[0037] Specifically, the relay self-test circuit of this embodiment is connected in parallel at both ends of the relay to be tested, and the relay to be tested includes a main positive relay, a main negative relay, and a pre-charge relay. Figure 3 As shown, the circuit includes: bypass capacitors C1 and C2, resistors R1, R2, R3, R4, R5, optocoupler U1, and diode D3; wherein:

[0038] The LED cathode of the optocoupler U1, the resistor R5, the resistor R4, and the LED anode of the optocoupler U1 are connected in series in sequence to form a loop, the lead terminal between the resistor R5 and the resistor R4 is connected to the power supply voltage V2, and the lead terminal between the LED cathode of the optocoupler U1 and the resistor R5 is connected to the first enable signal of the controller, that is, the MCU signal.

[0039] The power supply voltage V1 is connected to the collector of the optocoupler U1 through resistors R2 and R3 connected in series in sequence, the emitter of the optocoupler U1 is connected to the anode of the diode, and the cathode of the diode is connected to the rear end of the relay to be tested; the lead terminals between the resistors R2 and R3 are respectively connected to the front end of the relay to be tested, and are connected to the first sampling terminal AD of the controller through the resistor R1; the bypass capacitors C1 and C2 are connected in parallel between the first sampling terminal AD and the front end of the relay to be tested.

[0040] During operation, when the relay to be tested is not stuck, the voltage collected by the first sampling terminal AD of the controller is equal to the power supply voltage V1. When the relay to be tested is stuck, the front and rear ends of the relay to be tested can be regarded as the same point. At this time, the voltage collected by the first sampling terminal AD of the controller is equal to the divided voltage of the resistor R3 and the diode D3.

[0041] In the relay self-test circuit of this embodiment, after receiving the enable signal from the controller, the optocoupler U1 is controlled to be turned on. Correspondingly, the controller further determines whether the relay to be tested is stuck by the voltage collected by the first sampling terminal AD. In order to ensure the stability of the voltage collected by the first sampling terminal AD, bypass capacitors C1 and C2 are provided. At the same time, the unidirectional conductivity of the diode D3 is also used to protect the relay self-test circuit from damage.

[0042] The resistor R1 plays a role of current limiting in the circuit. Further, in a preferred embodiment of the application, a capacitor C3 is connected in parallel between the first sampling terminal AD and the front end of the relay to be tested, so that the capacitor C3 and the resistor R1 form an RC low-pass filter circuit to filter out interference, so that the collected voltage of the first sampling terminal AD is more accurate.

[0043] In order to protect the first sampling terminal AD of the controller, the relay self-test circuit of this embodiment also includes Zener diodes D1 and D2, wherein: the terminals extending between the resistors R2 and R3 are respectively connected to the front end of the relay to be tested through the reverse-connected Zener diode D2, and are connected to the power supply voltage V1 through the forward-connected Zener diode D1.

[0044] In addition, the power supply voltage V1 of this embodiment is provided by the battery monitoring chip, and the power supply voltage V2 is provided by the vehicle low-voltage power supply, so that the entire relay self-test circuit does not require an external power supply, which is easy to install.

[0045] Specifically, the voltage sampling circuit of this embodiment is as follows: Figure 4 As shown, it includes a transistor Q1, an optocoupler U2, and resistors R6 to R11. In the voltage sampling circuit, the base of the transistor Q1 is connected to the second enable terminal CTRL1 of the controller, the emitter of the transistor Q1 is grounded, the collector of the transistor Q1 is connected to the LED cathode of the optocoupler U2, and the LED anode of the optocoupler U2 is connected to the power supply voltage VCC through the resistor R6; the power supply voltage VCC can also be directly provided by the power monitoring chip.

[0046] The first input terminal of the voltage sampling circuit is connected to the collector of the optocoupler U2 through resistors R7, R8, and R9 connected in series in sequence, and the emitter of the optocoupler U2 is connected to the second input terminal of the voltage sampling circuit through resistors R10 and R11 connected in series in sequence; the lead terminal between the resistor R10 and the resistor R11 is connected to the second sampling terminal AD1 of the controller.

[0047] The controller can control the transistor Q1 to be turned on by sending a signal through the second enable terminal CTRL1. At this time, the optical coupler U2 is also turned on accordingly, so that the controller collects voltage through the second sampling terminal AD1.

[0048] In this embodiment, two voltage acquisition circuits are provided, namely, a first voltage acquisition circuit and a second voltage acquisition circuit, wherein the first voltage acquisition circuit is used to acquire a first sampled voltage between the rear end LINK+ of the main positive relay and the front end PACK- of the main negative relay, and the second voltage acquisition circuit is used to acquire a second sampled voltage between the rear end LINK+ of the main positive relay and the rear end LINK- of the main negative relay. The first and second voltage acquisition circuits have the same overall structure, and in specific implementation, their respective internal resistance values ​​can be flexibly configured as required.

[0049] In summary, the present application uses a redundant design to perform both self-checking of the relay and cross voltage sampling judgment, thereby improving the efficiency of relay adhesion detection. The system structure of the present application is simple, easy to operate, easy to install, and has low cost, and can be widely used.

[0050] At the same time, according to the above-mentioned relay adhesion redundancy detection system of the new energy vehicle power system, this embodiment also proposes a relay adhesion redundancy detection method of the new energy vehicle power system, and the method includes the following steps:

[0051] Step S1, the vehicle power system is initialized. After the initialization is completed, the main positive relay, the main negative relay, and the pre-charge relay are all in the disconnected state.

[0052] Step S2, the controller enables the relay self-test circuits connected in parallel at both ends of the main positive relay, the main negative relay, and the pre-charging relay to determine whether the main positive relay, the main negative relay, and the pre-charging relay are stuck; when no sticking occurs, proceed to the next step.

[0053] Among them, when the voltage collected by the first sampling terminal AD of the controller is equal to the power supply voltage V1, it means that the relay under test is not stuck; when the voltage collected by the first sampling terminal AD of the controller is equal to the divided voltage on the resistor R3 and the diode D3, it means that the relay under test is stuck.

[0054] Step S3: During the process of pre-charging and powering off the vehicle, the controller enables the voltage acquisition circuit connected between the rear end LINK+ of the main positive relay and the front end PACK- of the main negative relay to obtain the first sampling voltage, and the voltage acquisition circuit between the rear end LINK+ of the main positive relay and the rear end LINK- of the main negative relay to obtain the second sampling voltage, and further determines whether the main positive relay, pre-charging relay and main negative relay are adhered according to the first sampling voltage and the second sampling voltage; if adhesion is found, immediately stop detection and report the fault. Specifically including:

[0055] Step S31, when the main positive relay, the main negative relay, and the pre-charge relay are all in the disconnected state, the controller enables the voltage acquisition circuit connected between the rear end LINK+ of the main positive relay and the front end PACK- of the main negative relay to obtain the first sampling voltage. When the first sampling voltage is not 0, it is judged that the main positive relay is adhered, and the detection is immediately stopped and the fault is reported; when the main positive relay is not adhered, proceed to the next step;

[0056] Step S32, close the pre-charge relay, and the controller enables the voltage acquisition circuit connected between the rear end LINK+ of the main positive relay and the rear end LINK- of the main negative relay to obtain the second sampling voltage. If it is detected that the second sampling voltage is not 0 and rises rapidly (not being 0 may be because the load capacitor is not fully discharged, so the second sampling voltage rises rapidly while not being 0, which can indicate that the pre-charge occurs in advance), it is determined that the main negative relay is adhered, and the detection is stopped immediately and the fault is reported; when the main negative relay is not adhered, proceed to the next step;

[0057] Step S33, close the main negative relay, and disconnect the pre-charging relay after the pre-charging is completed, and close the main positive relay at the same time to complete the power-on detection;

[0058] Step S34, when power is turned off, disconnect the main positive relay. If the controller enables the voltage acquisition circuit connected between the rear end LINK+ of the main positive relay and the front end PACK- of the main negative relay to obtain the first sampling voltage, when the first sampling voltage is not 0 and lasts for a preset time (not being 0 may be that the load capacitor is not fully discharged. To eliminate this situation, a preset time is set to wait for the load capacitor to be fully discharged. The preset time can be determined according to the size of the capacitor), it is judged that the pre-charge relay is stuck. At this time, the detection is stopped immediately and the fault is reported.

[0059] Furthermore, before step S32, the controller also enables the voltage acquisition circuit connected between the rear end LINK+ of the main positive relay and the rear end LINK- of the main negative relay to obtain a second sampling voltage. If the second sampling voltage is 0, the next step is directly executed; if the second sampling voltage is not 0, it means that the load capacitor is not fully discharged, and the next step is not executed until the second sampling voltage is 0. If the load capacitor is not fully discharged, a large voltage difference will appear between the power battery and the load capacitor at the beginning of pre-charging, thereby generating a large current to damage the circuit.

[0060] The present invention adopts a redundant design method. On the one hand, it preliminarily determines whether the relay is stuck according to the voltage collected by the relay self-test circuit, and then further determines whether the relay is stuck according to the voltage cross-collected by the voltage sampling circuit, thereby forming a redundant detection. Only when both of them determine that no adhesion occurs, it is considered that the adhesion detection has passed, thereby improving the efficiency of the relay adhesion detection. In this way, the relay adhesion fault can be discovered in time before the vehicle officially starts pre-charging and powering up, ensuring that the battery system can carry out the pre-charging and powering-up process normally.

[0061] The present invention is described above by way of example in conjunction with the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-mentioned methods. As long as various non-substantial improvements are made using the method concept and technical solution of the present invention; or the above concept and technical solution of the present invention are directly applied to other occasions without improvement, they are all within the protection scope of the present invention.

Claims

1. A relay adhesion redundancy detection system for a new energy vehicle power system, the system comprises a power battery positive electrode, a main positive relay, a load, a main negative relay, and a power battery negative electrode in sequence, and at the same time, a pre-charge relay and a pre-charge resistor are connected in series in parallel at both ends of the main positive relay, and a load capacitor is connected in parallel at both ends of the load, characterized in that: The system further comprises: a battery monitoring chip and a controller connected to each other, wherein the battery monitoring chip comprises a plurality of relay self-test circuits and a plurality of voltage sampling circuits, wherein: The multiple relay self-test circuits are respectively connected in parallel at both ends of the main positive relay, the main negative relay, and the pre-charge relay; the multiple voltage sampling circuits are respectively connected between the rear end LINK+ of the main positive relay and the front end PACK- of the main negative relay, and between the rear end LINK+ of the main positive relay and the rear end LINK- of the main negative relay; the controller is respectively connected to the relay self-test circuit and the voltage sampling circuit, and is used to perform relay adhesion redundancy detection according to the collected voltage signals.

2. The relay adhesion redundancy detection system of a new energy vehicle power system according to claim 1 is characterized in that: The relay self-test circuit includes: bypass capacitors C1 and C2, resistors R1, R2, R3, R4, R5, optocoupler U1, and diode D3; Wherein: the LED cathode of the optocoupler U1, the resistor R5, the resistor R4, and the LED anode of the optocoupler U1 are connected in series in sequence to form a loop, the lead terminal between the resistor R5 and the resistor R4 is connected to the power supply voltage V2, and the lead terminal between the LED cathode of the optocoupler U1 and the resistor R5 is connected to the first enable signal of the controller; The power supply voltage V1 is connected to the collector of the optocoupler U1 through resistors R2 and R3 connected in series in sequence, the emitter of the optocoupler U1 is connected to the anode of the diode, and the cathode of the diode is connected to the rear end of the relay to be tested; the lead terminals between the resistors R2 and R3 are respectively connected to the front end of the relay to be tested, and are connected to the first sampling terminal AD of the controller through the resistor R1; the bypass capacitors C1 and C2 are connected in parallel between the first sampling terminal AD and the front end of the relay to be tested.

3. The relay adhesion redundancy detection system of a new energy vehicle power system according to claim 2 is characterized in that: A capacitor C3 is connected in parallel between the first sampling terminal AD and the front end of the relay to be tested, and the capacitor C3 and the resistor R1 form an RC low-pass filter circuit.

4. A relay adhesion redundancy detection system for a new energy vehicle power system according to claim 2 or 3, characterized in that: The relay self-test circuit also includes Zener diodes D1 and D2, wherein: the terminals extending between the resistors R2 and R3 are respectively connected to the front end of the relay to be tested through the reverse-connected Zener diode D2, and are connected to the power supply voltage V1 through the forward-connected Zener diode D1.

5. The relay adhesion redundancy detection system of a new energy vehicle power system according to claim 4 is characterized in that: The power supply voltage V1 is provided by the battery monitoring chip; the power supply voltage V2 is provided by the vehicle low-voltage power supply.

6. The relay adhesion redundancy detection system of a new energy vehicle power system according to claim 1 is characterized in that: In the voltage sampling circuit, the base of the transistor Q1 is connected to the second enable terminal CTRL1 of the controller, the emitter of the transistor Q1 is grounded, the collector of the transistor Q1 is connected to the LED cathode of the optocoupler U2, and the LED anode of the optocoupler U2 is connected to the power supply voltage VCC through the resistor R6; The first input terminal of the voltage sampling circuit is connected to the collector of the optocoupler U2 through resistors R7, R8, and R9 connected in series in sequence, and the emitter of the optocoupler U2 is connected to the second input terminal of the voltage sampling circuit through resistors R10 and R11 connected in series in sequence; the lead terminal between the resistor R10 and the resistor R11 is connected to the second sampling terminal AD1 of the controller.

7. A relay adhesion redundancy detection method for a new energy vehicle power system according to any one of claims 1 to 6, characterized in that: The method comprises the following steps: Step S1, the vehicle power system is initialized. After the initialization is completed, the main positive relay, the main negative relay, and the pre-charge relay are all in the disconnected state; Step S2, the controller enables the relay self-check circuits connected in parallel at both ends of the main positive relay, the main negative relay, and the pre-charge relay to determine whether the main positive relay, the main negative relay, and the pre-charge relay are adhered; if no adhesion occurs, proceed to the next step; Step S3, during the process of pre-charging and powering off the whole vehicle, the controller enables the voltage acquisition circuit connected between the rear end LINK+ of the main positive relay and the front end PACK- of the main negative relay to obtain the first sampling voltage, and the voltage acquisition circuit between the rear end LINK+ of the main positive relay and the rear end LINK- of the main negative relay to obtain the second sampling voltage, and further determines whether the main positive relay, the pre-charging relay and the main negative relay are adhered according to the first sampling voltage and the second sampling voltage; when adhesion is found, the detection is stopped immediately and the fault is reported.

8. A relay adhesion redundancy detection method for a new energy vehicle power system according to the system of claim 7, characterized in that: In step S2, when the voltage collected by the first sampling terminal AD of the controller is equal to the power supply voltage V1, it indicates that the relay to be tested is not stuck; when the voltage collected by the first sampling terminal AD of the controller is equal to the divided voltage across the resistor R3 and the diode D3, it indicates that the relay to be tested is stuck.

9. The relay adhesion redundancy detection method of a new energy vehicle power system according to claim 7, characterized in that: The step S3 comprises: Step S31, when the main positive relay, the main negative relay, and the pre-charge relay are all in the disconnected state, the controller enables the voltage acquisition circuit connected between the rear end LINK+ of the main positive relay and the front end PACK- of the main negative relay to obtain the first sampling voltage. When the first sampling voltage is not 0, it is judged that the main positive relay is adhered, and the detection is immediately stopped and the fault is reported; when the main positive relay is not adhered, proceed to the next step; Step S32, close the pre-charge relay, and the controller enables the voltage acquisition circuit connected between the rear end LINK+ of the main positive relay and the rear end LINK- of the main negative relay to obtain a second sampling voltage. If it is detected that the second sampling voltage is not 0 and rises rapidly, it is determined that the main negative relay is adhered, and the detection is immediately stopped and the fault is reported; when the main negative relay is not adhered, proceed to the next step; Step S33, close the main negative relay, and disconnect the pre-charging relay after the pre-charging is completed, and close the main positive relay at the same time to complete the power-on detection; Step S34, when power is off, disconnect the main positive relay. If the controller enables the voltage acquisition circuit connected between the rear end LINK+ of the main positive relay and the front end PACK- of the main negative relay to obtain the first sampling voltage, when the first sampling voltage is not 0 and lasts for a preset time, it is judged that the pre-charge relay is stuck. At this time, the detection is stopped immediately and the fault is reported.

10. The relay adhesion redundancy detection method of a new energy vehicle power system according to claim 9, characterized in that: The step S3 also includes: before the step S32, the controller enables the voltage acquisition circuit connected between the rear end LINK+ of the main positive relay and the rear end LINK- of the main negative relay to obtain a second sampling voltage. If the second sampling voltage is 0, the next step is directly executed; if the second sampling voltage is not 0, it means that the load capacitor is not fully discharged, and the next step is executed only when the second sampling voltage is 0.

Images