A high voltage interlock detection strategy with complete diagnostics

Abstract

The present invention discloses a high-voltage interlock detection strategy that can be fully diagnosed, including the following steps: Step 1: complete all initializations when the whole vehicle is powered on, and set the high-voltage interlock sampling flag to invalid; Step 2: detect that the high-voltage interlock detection conditions specified by the user are met, start periodic sampling detection, and after the nth sampling is completed, set the high-voltage interlock sampling flag to valid; Step 3: calculate the voltage threshold corresponding to the high-voltage interlock signal under different working conditions; Step 4: The high-voltage interlock detection module detects the high-voltage interlock signal, and judges the AD average value of the continuous sampling input of step 2 according to the voltage threshold of step 3, and analyzes the corresponding working conditions; Step 5: detect that the high-voltage interlock detection conditions specified by the user are met, and stop the periodic detection. In the present invention, by inputting a specified signal to the high-voltage interlock detection circuit, and then using the detection strategy for sampling control and calculation judgment, the detection is more complete and safe.

Description

Technical Field

[0001] The present invention relates to the technical field of BMS for new energy vehicles, and in particular to a high-voltage interlock detection strategy capable of complete diagnosis. Background Art

[0002] New energy vehicles are developing rapidly. The biggest difference between new energy vehicles and traditional gasoline vehicles is that new energy vehicles rely on high voltage and high current to provide power for vehicles. Therefore, high voltage safety issues are crucial in the design of new energy vehicles. Generally, high voltage interlock circuits are used as safety monitoring systems for high voltage circuits to monitor the on-off status of various high voltage components in electric vehicles.

[0003] In the prior art, the traditional detection scheme 1 is: inputting a high level from the input end, and detecting whether the output is a high level at the output end. However, the defect of this scheme is: it is impossible to accurately diagnose abnormalities, especially for power short circuit conditions, resulting in blind spots in the analysis of accident vehicle problems, and also bringing certain electric shock risks to maintenance work; another detection scheme 2 is: inputting a PWM signal from the input end, and detecting the output frequency and duty cycle at the output end. However, the defect of this scheme is: in an environment with large electromagnetic interference, there will be large errors in the frequency and duty cycle, which is prone to misdiagnosis, and then causing the electric vehicle to stop charging or parking without abnormality. Summary of the invention

[0004] The present invention provides a more complete and safe high-voltage interlock detection strategy that can be fully diagnosed and can solve at least one of the above technical problems.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0006] A fully diagnostic high voltage interlock detection strategy includes the following steps:

[0007] Step 1: Complete all initializations when the vehicle is powered on, and set the high-voltage interlock sampling flag to invalid;

[0008] Step 2: Check if the user-specified high-voltage interlock detection conditions are met and start periodic sampling detection. The sampling period is T. After the nth sampling is completed, the high-voltage interlock sampling flag is set to valid and the calculation is started:

[0009] The n AD values ​​obtained by n samplings are first sorted, and then the middle n / 2 values ​​are selected for average calculation. After the stable average value x is obtained, it is input into the high-voltage interlock detection module;

[0010] Continue sampling for the n+1th time to obtain the n+1th sampling value, remove the first sampling value, obtain n sampling values ​​again, repeat the steps of step 2, and so on, continuously update the AD sampling value, and continuously update the output average value;

[0011] Step 3: Calculate the voltage threshold corresponding to the high-voltage interlock signal under different working conditions:

[0012] When the input pull-up control switch S1 and the output pull-up control switch S2 are both disconnected and the high-voltage interlock signal is short-circuited to the power supply: the vehicle power supply voltage floats between 9 and 16 V, and V = R4 / (R2+R4) = 2.25 to 4 V. Considering the ±10% error, the voltage threshold is taken as 2 to 4.4 V.

[0013] When all high-voltage interlock signals are at low level: the voltage threshold is theoretically 0V, and considering the ground drift voltage factor, it is taken as 0.7V;

[0014] When only the input pull-up control switch S1 is closed and the high-voltage interlock signal is normal: the pull-up stable voltage is 12V, and V=R4 / (R1+R2+R4)=2V, minus 10% error, the voltage threshold is 1.8V;

[0015] When only the output pull-up control switch S2 is closed and the high-voltage interlock signal is normal: the pull-up stable voltage is 5V, and V=R4 / (R3+R4)=2.5V, minus 10% error, the voltage threshold is 2.25V;

[0016] Step 4: The high-voltage interlock detection module detects the high-voltage interlock signal, determines the AD average value of the continuous sampling input in step 2 according to the voltage threshold of step 3, and analyzes the corresponding working condition:

[0017] The MCU chip detects the AD port level. If the detection level signal is ≥2V, it means that the high-voltage interlock signal is short-circuited to the power supply, and a fault is directly reported. If the detection level signal is ≤0.7V, it means that the high-voltage interlock signal is normal, and the next step of detection is continued;

[0018] The MCU chip controls the input pull-up control switch S1 to be closed. If the detection level signal is ≤0.7V, it means that the high-voltage interlock signal is disconnected from the power supply and a fault is directly reported. If the detection level signal is ≥1.8V, it means that the high-voltage interlock signal is normal and the next step of detection is continued.

[0019] The MCU chip controls the input pull-up control switch S1 to be disconnected and the output pull-up control switch S2 to be closed. If the detection level signal is ≤0.7V, it means that the high-voltage interlock signal is short-circuited to the ground, and a fault is directly reported. If the detection level signal is ≥2.25V, it means that the high-voltage interlock signal is normal, and the output pull-up control switch S2 is disconnected to continue the next cycle of detection.

[0020] Step 5: Detect if the user-specified high-voltage interlock detection conditions are met and stop the cycle detection.

[0021] Furthermore, in step 1, according to user needs, the high-voltage interlock detection conditions include: normal power supply, charging state and discharging state.

[0022] Furthermore, in step 5, according to user needs, closing the high-voltage interlock detection conditions includes: power supply abnormality, non-charging state and discharging state.

[0023] Furthermore, in step 2, the sampling period T≤1ms, and the number of sampling times n≥16.

[0024] Furthermore, in step 3, when only the output pull-up control switch S2 is closed and the high-voltage interlock signal is normal, the value of the voltage threshold is lower than 2.25V.

[0025] Further, a high-voltage interlock detection system capable of complete diagnosis is adopted, the high-voltage interlock detection system capable of complete diagnosis comprises an OBC module, a high-voltage interlock detection module and a high-voltage interlock connector, the high-voltage interlock detection module is arranged in the OBC module and connected in parallel to the high-voltage interlock connector;

[0026] The high-voltage interlock detection module includes a high-voltage interlock detection circuit, which includes an input pull-up resistor R1 and an input pull-up control switch S1 connected in series at the output port of the high-voltage interlock detection module, and a short-circuit detection resistor R2, an output pull-up resistor R3, an MCU pull-down resistor R4, an output pull-up control switch S2 and an MCU chip connected in parallel at the output port of the high-voltage interlock detection module, wherein an ADC sampling unit is provided in the MCU chip.

[0027] Furthermore, the input pull-up resistor R1 is used to detect the short circuit of the high-voltage interlock signal to the power supply, the short-circuit detection resistor R2 is used to detect the short circuit of the high-voltage interlock signal to the power supply, the output pull-up resistor R3 is used to detect the short circuit of the high-voltage interlock signal to the ground, the MCU pull-down resistor R4 is used to calculate the voltage AD value, the on-off state of the input pull-up control switch S1 and the output pull-up control switch S2 are both controlled by the MCU chip, and the ADC sampling unit is used to continuously update the sampling signal and filter out interference signals.

[0028] Furthermore, the high-voltage interlock detection module is connected in parallel to the high-voltage interlock connector via a plug-in connector installed at an input / output port for transmitting a high-voltage interlock signal.

[0029] Furthermore, the input port of the high-voltage interlock connector inputs high-voltage current, and the output port outputs high-voltage current.

[0030] The beneficial effects of the present invention are embodied in:

[0031] 1. In the present invention, the high-voltage interlock detection module is connected in parallel to the high-voltage interlock connector. By inputting a specified signal into the high-voltage interlock detection circuit and then using the detection strategy for sampling control and calculation judgment, it is possible to directly and accurately distinguish whether the high-voltage interlock signal is open circuit, short circuit to the power supply or short circuit to the ground. At the same time, it is also possible to detect whether the high-voltage interlock signal has poor contact. This not only enables rapid and accurate diagnosis of the problem of the accident vehicle, but also avoids the risks caused by misdiagnosis or electric shock during maintenance, making the detection more complete and safer.

[0032] 2. In the present invention, on the one hand, the threshold of the AD value diagnosis method is wider and the ability to resist EMC interference is stronger, which can improve the detection accuracy. On the other hand, with the high-voltage interlock sampling algorithm, the interference can be filtered very smoothly, greatly reducing the probability of misdiagnosis. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The drawings described herein are used to provide further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute improper limitations on the present application.

[0034] Figure 1 It is a flow chart of a high voltage interlock detection strategy according to an embodiment of the present invention.

[0035] Figure 2 It is a schematic block diagram of the overall structure of a high-voltage interlock detection system according to an embodiment of the present invention.

[0036] Figure 3 Schematic diagram of a high voltage interlock detection circuit according to an embodiment of the present invention.

[0037] Figure 4 It is a structural block diagram of a computer device according to an embodiment of the present invention.

[0038] The components in the attached drawings are marked as follows: 1. OBC module; 2. High-voltage interlock detection module; 3. High-voltage interlock connector; 4. Plug-in strip. DETAILED DESCRIPTION

[0039] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. In the absence of conflict, the embodiments in this application and the features in the embodiments can be combined with each other. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0040] It should be noted that those skilled in the art can understand that all or part of the steps in implementing the above-mentioned embodiment strategies can be completed by instructing the relevant hardware through a program, so the present application can be in the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present application can be in the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

[0041] See also Figure 2-Figure 3 , an embodiment of the present invention provides a high-voltage interlock detection strategy that can be fully diagnosed, using a high-voltage interlock detection system that can be fully diagnosed, the high-voltage interlock detection system that can be fully diagnosed includes an OBC module 1, a high-voltage interlock detection module 2 and a high-voltage interlock connector 3, the high-voltage interlock detection module 2 is arranged in the OBC module 1, and is connected in parallel to the high-voltage interlock connector 3;

[0042] The high-voltage interlock detection module 2 includes a high-voltage interlock detection circuit, which includes an input pull-up resistor R1 and an input pull-up control switch S1 connected in series at the output port of the high-voltage interlock detection module 2, and a short-circuit detection resistor R2, an output pull-up resistor R3, an MCU pull-down resistor R4, an output pull-up control switch S2 and an MCU chip connected in parallel at the output port of the high-voltage interlock detection module 2, wherein an ADC sampling unit is provided in the MCU chip.

[0043] In the present invention, the high-voltage interlock detection module is connected in parallel to the high-voltage interlock connector. By inputting a specified signal into the high-voltage interlock detection circuit and then performing sampling control and calculation judgment, it is possible to directly and accurately distinguish whether the high-voltage interlock signal is open circuit, short-circuited to the power supply or short-circuited to the ground. At the same time, it is also possible to detect whether the high-voltage interlock signal has poor contact. This not only enables rapid and accurate diagnosis of the problems of the accident vehicle, but also avoids the risks caused by misdiagnosis or electric shock during maintenance, making the detection more complete and safer.

[0044] See also Figure 2-Figure 3In this embodiment, the input pull-up resistor R1 is used to detect the short circuit of the high-voltage interlock signal to the power supply, the short-circuit detection resistor R2 is used to detect the short circuit of the high-voltage interlock signal to the power supply, the output pull-up resistor R3 is used to detect the short circuit of the high-voltage interlock signal to the ground, the MCU pull-down resistor R4 is used to calculate the voltage AD value, the on-off state of the input pull-up control switch S1 and the output pull-up control switch S2 are controlled by the MCU chip, and the ADC sampling unit is used to continuously update the sampling signal and filter out interference signals. The threshold of the AD value diagnosis method is wider, and the ability to resist EMC interference is stronger, which can improve the detection accuracy. Combined with the high-voltage interlock sampling algorithm, the interference can be filtered very smoothly, greatly reducing the probability of misdiagnosis.

[0045] See also Figure 2-Figure 3 In this embodiment, the high-voltage interlock detection module 2 is connected in parallel to the high-voltage interlock connector 3 via the plug-in row 4 installed at the input and output ports, and is used to transmit the high-voltage interlock signal. The OBC module 1 is the abbreviation of the existing on-board charger in the electric vehicle system (On Board Charger), and its main function is: the grid voltage is connected to the on-board charger via the ground AC charging pile and the AC charging port to charge the electric battery. The OBC in the prior art is generally an isolated OBC by default, which means that an electrical isolation layer with a withstand voltage of 2500V-3750V is required between the grid side and the vehicle side to improve electrical safety. The high-voltage interlock detection module 2 is arranged in the OBC module 1, which plays a role in the safety monitoring of the high-voltage circuit of the electric vehicle system, and realizes a detachable quick electrical plug connection with the high-voltage interlock connector 3 in the electric vehicle system through the plug-in row 4.

[0046] See also Figure 2-Figure 3 In this embodiment, the input port of the high-voltage interlock connector 3 inputs high-voltage current, and the output port outputs high-voltage current. The high-voltage interlock connector 3 is an existing high-voltage interlock connection structure in the tram system. By conducting high-voltage current, it can not only stop the tram system from being powered on for an incomplete circuit detected before the vehicle is powered on, thus avoiding vehicle accidents caused by virtual connection and other problems, but also prevent safety accidents caused by human error.

[0047] See also Figure 1-Figure 3 , an embodiment of the present invention provides a high voltage interlock detection strategy that can be fully diagnosed, including the following steps:

[0048] Step 1: Complete all initializations when the vehicle is powered on, and set the high-voltage interlock sampling flag to invalid;

[0049] Step 2: Check if the user-specified high-voltage interlock detection conditions are met and start periodic sampling detection. The sampling period is T. After the nth sampling is completed, the high-voltage interlock sampling flag is set to valid and the calculation is started:

[0050] The n AD values ​​obtained by sampling n times are first sorted, and then the middle n / 2 values ​​are selected for average calculation. After the stable average value x is obtained, it is input into the high-voltage interlock detection module 2;

[0051] Continue sampling for the n+1th time to obtain the n+1th sampling value, remove the first sampling value, obtain n sampling values ​​again, repeat the steps of step 2, and so on, continuously update the AD sampling value, and continuously update the output average value;

[0052] Step 3: Calculate the voltage threshold corresponding to the high-voltage interlock signal under different working conditions:

[0053] When the input pull-up control switch S1 and the output pull-up control switch S2 are both disconnected and the high-voltage interlock signal is short-circuited to the power supply: the vehicle power supply voltage floats between 9 and 16 V, and V = R4 / (R2+R4) = 2.25 to 4 V. Considering the ±10% error, the voltage threshold is taken as 2 to 4.4 V.

[0054] When all high-voltage interlock signals are at low level: the voltage threshold is theoretically 0V, and considering the ground drift voltage factor, it is taken as 0.7V;

[0055] When only the input pull-up control switch S1 is closed and the high-voltage interlock signal is normal: the pull-up stable voltage is 12V, and V=R4 / (R1+R2+R4)=2V, minus 10% error, the voltage threshold is 1.8V;

[0056] When only the output pull-up control switch S2 is closed and the high-voltage interlock signal is normal: the pull-up stable voltage is 5V, and V=R4 / (R3+R4)=2.5V, minus 10% error, the voltage threshold is 2.25V;

[0057] Step 4: The high-voltage interlock detection module 2 detects the high-voltage interlock signal, determines the AD average value of the continuous sampling input in step 2 according to the voltage threshold of step 3, and analyzes the corresponding working condition:

[0058] The MCU chip detects the AD port level. If the detection level signal is ≥2V, it means that the high-voltage interlock signal is short-circuited to the power supply, and a fault is directly reported. If the detection level signal is ≤0.7V, it means that the high-voltage interlock signal is normal, and the next step of detection is continued;

[0059] The MCU chip controls the input pull-up control switch S1 to be closed. If the detection level signal is ≤0.7V, it means that the high-voltage interlock signal is disconnected from the power supply and a fault is directly reported. If the detection level signal is ≥1.8V, it means that the high-voltage interlock signal is normal and the next step of detection is continued.

[0060] The MCU chip controls the input pull-up control switch S1 to be disconnected and the output pull-up control switch S2 to be closed. If the detection level signal is ≤0.7V, it means that the high-voltage interlock signal is short-circuited to the ground, and a fault is directly reported. If the detection level signal is ≥2.25V, it means that the high-voltage interlock signal is normal, and the output pull-up control switch S2 is disconnected to continue the next cycle of detection.

[0061] Step 5: Detect if the user-specified high-voltage interlock detection conditions are met and stop the cycle detection.

[0062] In the present invention, a high-voltage interlock detection module is connected in parallel to a high-voltage interlock connector, and a specified signal is input into the high-voltage interlock detection circuit, and then a detection strategy is used to perform sampling control and calculation judgment. The AD value diagnosis method has a wider threshold and a stronger ability to resist EMC interference, which can improve the detection accuracy. In conjunction with the high-voltage interlock sampling algorithm, interference can be filtered very smoothly, greatly reducing the probability of misdiagnosis, and can directly and accurately distinguish whether the high-voltage interlock signal is open circuit, short circuit to the power supply, or short circuit to the ground.

[0063] See also Figure 1 In this embodiment, in step 1, according to user needs, the high-voltage interlock detection conditions include: normal power supply, charging state and discharging state, which can cover the common working states of the OBC module 1.

[0064] See also Figure 1 In this embodiment, in step 5, according to user needs, the conditions for closing the high-voltage interlock detection include: power supply abnormality, non-charging state and discharging state, which can cover the common fault states of the OBC module 1.

[0065] See also Figure 1 In this embodiment, in step 2, the sampling period T≤1ms, the sampling times n≥16. Normally, the more times the sampling is performed, the smoother the filtering is. The empirical value is 16 times, and the sampling period interval should be as short as possible to ensure the continuity of sampling and the accuracy of detection.

[0066] See also Figure 1In this embodiment, in step 3, when only the output pull-up control switch S2 is closed and the high-voltage interlock signal is normal, the voltage threshold value is lower than 2.25V, R1 is an input pull-up resistor, and its resistance is set to 2kΩ, which is used to detect the open circuit, R2 is a short-circuit detection resistor, and its resistance is set to 3kΩ, which is used to detect the short circuit to the power supply, R3 is an output pull-up resistor, and its resistance is set to 1kΩ, which is used to detect the short circuit to the ground, and R4 is an MCU pull-down resistor, and its resistance is set to 1kΩ, which is used to calculate according to the sampled voltage AD value; S1 is an input pull-up control switch, which can be controlled by an MCU chip, and S2 is an output pull-up control switch, which can be controlled by an MCU chip. The MCU chip uses a microprocessor chip that can be purchased in the prior art, and is provided with an ADC sampling unit with a sampling function, which is used to continuously update the sampling signal and filter out interference signals.

[0067] In one embodiment of the present application, taking the short circuit of the power supply with the largest interference as an example, 16 voltage AD value samplings are performed, and the sampling data table is shown in Table 1 below:

[0068] Table 1 Sampling data table

[0069] Sampling times 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Sampling value (V) 3.11 3.15 2.01 2.5 3.1 3.13 3.15 3.16 3.14 3.17 3.65 3.37 3.16 3.14 3.13 3.15 After sorting (V) 2.01 2.5 3.1 3.11 3.13 3.13 3.14 3.14 3.15 3.15 3.15 3.16 3.16 3.17 3.37 3.65

[0070] After sorting in order of numerical value, the middle 8 values ​​are taken to obtain the average value x=3.144V. From the actual test, this method can effectively filter out the interference caused by vehicle startup or load dumping, further proving that this strategy has strong anti-EMC interference ability.

[0071] See also Figure 4 The embodiment of the present invention further provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor executes the steps of the high-voltage interlock detection strategy that can be fully diagnosed. The steps of the high-voltage interlock detection strategy that can be fully diagnosed here can be the steps in the high-voltage interlock detection strategy that can be fully diagnosed in each of the above-mentioned embodiments.

[0072] In summary, in the present invention, the high-voltage interlock detection module is connected in parallel to the high-voltage interlock connector. By inputting a specified signal into the high-voltage interlock detection circuit and then using the detection strategy for sampling control and calculation judgment, it is possible to directly and accurately distinguish whether the high-voltage interlock signal is open-circuited, short-circuited to the power supply or short-circuited to the ground. At the same time, it is also possible to detect whether the high-voltage interlock signal has poor contact. This not only enables the problem of the accident vehicle to be diagnosed quickly and accurately, but also avoids the risks caused by misdiagnosis or electric shock during maintenance, and the detection is more complete and safer. On the one hand, the threshold of the AD value diagnosis method is wider and the ability to resist EMC interference is stronger, which can improve the detection accuracy. On the other hand, in conjunction with the high-voltage interlock sampling algorithm, the interference can be filtered very smoothly, greatly reducing the chance of misdiagnosis.

[0073] It should be understood that the examples and implementation modes described herein are for illustrative purposes only and are not intended to limit the present invention. Those skilled in the art may make various modifications or changes based on the examples and implementation modes. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A fully diagnosable high voltage interlock detection strategy, characterized in that: A high-voltage interlock detection system capable of complete diagnosis is used, the high-voltage interlock detection system capable of complete diagnosis comprising an OBC module (1), a high-voltage interlock detection module (2) and a high-voltage interlock connector (3), wherein the high-voltage interlock detection module (2) is arranged in the OBC module (1) and connected in parallel to the high-voltage interlock connector (3); The high-voltage interlock detection module (2) comprises a high-voltage interlock detection circuit, the high-voltage interlock detection circuit comprising an input pull-up resistor R1 and an input pull-up control switch S1 connected in series at an output port of the high-voltage interlock detection module (2), and a short-circuit detection resistor R2, an output pull-up resistor R3, an MCU pull-down resistor R4, an output pull-up control switch S2 and an MCU chip connected in parallel at the output port of the high-voltage interlock detection module (2), wherein an ADC sampling unit is provided in the MCU chip; Among them, R1:R2:R3:R4=2:3:1:1; The following steps are involved: Step 1: Complete all initializations when the vehicle is powered on, and set the high-voltage interlock sampling flag to invalid; Step 2: Check if the user-specified high-voltage interlock detection conditions are met and start periodic sampling detection. The sampling period is T. After the nth sampling is completed, the high-voltage interlock sampling flag is set to valid and the calculation is started: The n AD values ​​obtained by sampling n times are first sorted, and then the middle n / 2 values ​​are selected for average calculation, and after the stable average value x is obtained, it is input into the high-voltage interlock detection module (2); Continue sampling for the n+1th time to obtain the n+1th sampling value, remove the first sampling value, obtain n sampling values ​​again, repeat the steps of step 2, and so on, continuously update the AD sampling value, and continuously update the output average value; Step 3: Calculate the voltage threshold corresponding to the high-voltage interlock signal under different working conditions: When the input pull-up control switch S1 and the output pull-up control switch S2 are both disconnected and the high-voltage interlock signal is short-circuited to the power supply: the vehicle power supply voltage floats to 9-16V, and V=R4 / (R2+R4)=2.25-4V. Considering the error of ±10%, the voltage threshold is taken as 2-4.4V. When all high-voltage interlock signals are at low level: the voltage threshold is theoretically 0V, and considering the ground drift voltage factor, it is taken as 0.7V; When only the input pull-up control switch S1 is closed and the high-voltage interlock signal is normal: the pull-up stable voltage is 12V, and V = R4 / (R1+R2+R4) = 2V, minus 10% error, the voltage threshold is taken as 1.8V; When only the output pull-up control switch S2 is closed and the high-voltage interlock signal is normal: the pull-up stable voltage is 5V, and V = R4 / (R3+R4) = 2.5V, minus 10% error, the voltage threshold is taken as 2.25V; Step 4: The high-voltage interlock detection module (2) detects the high-voltage interlock signal, determines the AD average value of the continuous sampling input in step 2 according to the voltage threshold of step 3, and analyzes the corresponding working condition: The MCU chip detects the AD port level. If the detection level signal is ≥2V, it means that the high-voltage interlock signal is short-circuited to the power supply, and a fault is directly reported. If the detection level signal is ≤0.7V, it means that the high-voltage interlock signal is normal, and the next step of detection is continued; The MCU chip controls the input pull-up control switch S1 to be closed. If the detection level signal is ≤0.7V, it means that the high-voltage interlock signal is disconnected from the power supply and a fault is directly reported. If the detection level signal is ≥1.8V, it means that the high-voltage interlock signal is normal and the next step of detection is continued. The MCU chip controls the input pull-up control switch S1 to be disconnected and the output pull-up control switch S2 to be closed. If the detection level signal is ≤0.7V, it means that the high-voltage interlock signal is short-circuited to the ground, and a fault is directly reported. If the detection level signal is ≥2.25V, it means that the high-voltage interlock signal is normal, and the output pull-up control switch S2 is disconnected to continue the next cycle of detection. Step 5: Check if the user-specified high-voltage interlock detection conditions are met and stop the cycle detection; Wherein, in step 2, the sampling period T≤1ms, and the sampling times n≥16.

2. The fully diagnosable high voltage interlock detection strategy according to claim 1, characterized in that: In step 1, according to user needs, the high-voltage interlock detection conditions include: normal power supply, charging state and discharging state.

3. The fully diagnosable high voltage interlock detection strategy according to claim 1, characterized in that: In step 5, according to user needs, the closing high-voltage interlock detection conditions include: power supply abnormality, non-charging state and discharging state.

4. The fully diagnosable high voltage interlock detection strategy according to claim 1, characterized in that: In step 3, when only the output pull-up control switch S2 is closed and the high-voltage interlock signal is normal, the voltage threshold value is lower than 2.25V.

5. The fully diagnosable high voltage interlock detection strategy according to claim 1, characterized in that: The input pull-up resistor R1 is used to detect the short circuit of the high-voltage interlock signal to the power supply, the short-circuit detection resistor R2 is used to detect the short circuit of the high-voltage interlock signal to the power supply, the output pull-up resistor R3 is used to detect the short circuit of the high-voltage interlock signal to the ground, the MCU pull-down resistor R4 is used to calculate the voltage AD value, the on-off state of the input pull-up control switch S1 and the output pull-up control switch S2 are both controlled by the MCU chip, and the ADC sampling unit is used to continuously update the sampling signal and filter out interference signals.

6. The fully diagnosable high voltage interlock detection strategy according to claim 1, characterized in that: The high-voltage interlock detection module (2) is connected in parallel to the high-voltage interlock connector (3) via a plug-in connector (4) installed at an input and output port, and is used to transmit a high-voltage interlock signal.

7. The fully diagnosable high voltage interlock detection strategy according to claim 1, characterized in that: The input port of the high-voltage interlocking connector (3) inputs high-voltage current, and the output port outputs high-voltage current.

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