Contactor diagnosis method and device and vehicle

Abstract

The invention discloses a contactor diagnosis method and device and a vehicle, under the condition that a contactor in a sampling loop is disconnected, the method comprises the following specific steps: obtaining a first sampling voltage and a power supply voltage corresponding to two ends of a first sampling resistor in the sampling loop; according to the first sampling voltage, the power supply voltage and the first sampling resistance, equivalent resistance of the contactor is obtained through calculation, the obtained equivalent resistance of the contactor is compared with a resistance threshold value, the state of the contactor is determined, and the resistance threshold value is suitable for different power supply voltages. In the process, the state of the contactor is determined by comparing the calculated equivalent resistance with the resistance threshold value suitable for the current working condition, and compared with a current method of comparing a sampling voltage with a fixed voltage threshold value, the state of the contactor can be determined on different voltage platforms or under the condition that voltage fluctuation exists. And the state of the contactor can be diagnosed more quickly and accurately.

Description

Technical Field

[0001] The present application relates to the electrical field, and in particular to a contactor diagnosis method, device and vehicle. Background Art

[0002] In electric vehicles, contactors are used to control the flow of current and to establish or disconnect the current path between the battery system and the motor, thereby controlling the power supply to the motor. They play an important role in the vehicle's power system or braking system. Therefore, in order to ensure the normal operation of the contactor and the normal operation of the vehicle, it is necessary to diagnose the status of the contactor.

[0003] Currently, the contactor status is determined by calculating the difference between the sampled voltage and the battery pack voltage and comparing the difference with a set fixed voltage threshold. Since it takes longer for the voltage to reach the set fixed voltage threshold in the case of low voltage, the above method has the problem of not being able to respond quickly, and when the fixed voltage threshold used to determine the contactor status is inaccurate, the above method has the problem of incorrect contactor status determination. Summary of the invention

[0004] The embodiments of the present application provide a contactor diagnosis method, device and vehicle, which determine the contactor status by comparing the equivalent resistance and resistance threshold of the contactor, wherein the resistance threshold used for determination is adapted to different voltage platforms, and voltage fluctuations and the like are taken into account during the determination process. Therefore, the determination conditions of the above-mentioned contactor diagnosis method have stronger robustness, and can realize fast and accurate diagnosis of the contactor status under different voltage platforms and in the presence of voltage fluctuations.

[0005] In a first aspect, the present application provides a contactor diagnosis method. When a contactor is disconnected in a sampling loop, the method includes: obtaining a first sampling voltage and a power supply voltage, wherein the first sampling voltage is the voltage across a first sampling resistor in the sampling loop; determining an equivalent resistance of the contactor based on the first sampling voltage, the power supply voltage, and the first sampling resistor; determining a contactor state based on the equivalent resistance and a resistance threshold of the contactor, wherein the resistance threshold is applicable to different power supply voltages.

[0006] In the above process, the equivalent resistance of the contactor is calculated by the first sampling voltage and the power supply voltage, and the equivalent resistance of the contactor is compared with the resistance threshold to determine the contactor state, wherein the equivalent resistance is the impedance of the two ends of the contactor to the ground, and the resistance threshold is applicable to different power supply voltages. It is calculated by taking into account the situation that the voltage sampling is not synchronized due to voltage fluctuations. Compared with the current method of comparing the sampling voltage, the power supply voltage and the fixed voltage threshold, the judgment conditions for contactor diagnosis in the present application are more robust, and the contactor state can be diagnosed more quickly and accurately on different voltage platforms or in the presence of voltage fluctuations.

[0007] In a possible implementation, the sampling circuit also includes a second sampling resistor; the first end of the contactor is connected to the first end of the battery pack, the second end of the contactor is connected to the first end of the second sampling resistor, the second end of the second sampling resistor is connected to the first end of the first sampling resistor, and the second end of the first sampling resistor is connected to the second end of the battery pack.

[0008] In a possible implementation manner, the equivalent resistance of the contactor is determined according to the first sampled voltage, the power supply voltage, and the first sampled resistance. The specific calculation formula is as follows:

[0009]

[0010] Among them, Requivalent is the equivalent resistance of the contactor, U1 is the first sampling voltage, Upack is the power supply voltage, R1 is the first sampling resistor, and R2 is the second sampling resistor. The above formula can be determined by the connection relationship of each component in the sampling circuit, and the equivalent resistance of the contactor can be calculated by combining the specific values ​​of the first sampling resistor, the second sampling resistor, the first sampling voltage and the power supply voltage, so as to diagnose the state of the contactor.

[0011] In a possible implementation, before determining the contactor state according to the equivalent resistance and resistance threshold of the contactor, the method further includes: determining the resistance threshold according to the second sampled voltage and different voltage platforms, wherein the different voltage platforms are multiple power supply voltages within the voltage value range including the power supply voltage. For example, when the power supply voltage is 400V, a variety of different power supply voltages such as 200V, 300V, 400V, and 500V can be used. The simulation of the above different voltage platforms is to determine the limit threshold of the resistance, so that the resistance threshold finally determined is more accurate and applicable to different voltage platforms, thereby avoiding the occurrence of incorrect contactor state judgment caused by voltage fluctuations.

[0012] The second sampling voltage in the above process is determined based on the first sampling voltage, the preset voltage difference and the preset precision deviation; wherein the preset voltage difference is used to adjust the first sampling voltage when the first sampling voltage and the power supply voltage are not collected synchronously, and is the phase difference voltage of the preset disturbance peak and valley, and the preset precision deviation is the sampling precision deviation corresponding to the sensor collecting the first sampling voltage. The second sampling voltage can cover the working conditions of voltage fluctuation and sampling asynchronous, therefore, the resistance threshold determined based on the second sampling voltage is more accurate, making the conditions for contactor status judgment based on the resistance threshold more robust and the inspection result more accurate.

[0013] In a possible implementation manner, the calculation formula of the second sampling voltage is as follows:

[0014] U1′=(U1+m)*(1+n)%

[0015] Among them, U1′ is the second sampling voltage, U1 is the first sampling voltage, m is the preset voltage difference, and n is the preset accuracy deviation. The second sampling voltage calculated by the above formula can cover the working conditions of voltage fluctuation and asynchronous sampling, and takes into account the accuracy deviation of sensor sampling, so that a more accurate resistance threshold can be calculated in the subsequent calculation process.

[0016] In a possible implementation, the specific process of determining the resistance threshold according to the second sampling voltage and different voltage platforms is as follows: multiple predicted resistance thresholds are obtained according to the second sampling voltage, different voltage platforms, the first sampling resistor, the second sampling resistor, and the calculation formula of the equivalent resistance; the smallest predicted resistance threshold among the multiple predicted resistance thresholds is used as the resistance threshold. According to different voltage platforms, the second sampling voltages and sampling resistors corresponding to different voltage platforms, and the calculation formula provided in this application, the predicted resistance thresholds corresponding to multiple different voltage platforms can be obtained, and the smallest predicted resistance threshold is selected as the resistance threshold, so that the resistance threshold can be applied to as many different working conditions as possible, so that the contactor state can be judged more accurately.

[0017] In a possible implementation, the specific process of determining the contactor state according to the equivalent resistance and resistance threshold of the contactor is as follows: when the equivalent resistance of the contactor is greater than the resistance threshold, the contactor is predicted to be disconnected, and compared with the disconnection of the contactor in the sampling loop, the predicted state and the actual control state are the same, and it can be determined that the contactor is in a normal disconnected state; or, when the equivalent resistance of the contactor is less than or equal to the resistance threshold, the contactor is predicted to be closed, and compared with the disconnection of the contactor in the sampling loop, at this time, the predicted state of the contactor is different from the actual control state, and it is determined that the contactor is in an abnormal closed state, for example, a sintering state, etc. The calculated equivalent resistance is compared with the resistance threshold, and when the equivalent resistance is equal to or smaller than the resistance threshold determined under the worst working condition, it can be more accurately determined that the contactor is in a closed state, and when the judgment state is different from the actual control state of the contactor in the sampling loop, it can be determined that the contactor is in an abnormal state, so that a notification can be sent to the user device to avoid vehicle driving and safety problems caused by contactor abnormality.

[0018] In the second aspect, the present application provides a contactor diagnostic device, which includes an acquisition module and a processing module when the contactor is disconnected in the sampling loop. The acquisition module is used to acquire a first sampling voltage and a power supply voltage, wherein the first sampling voltage is the voltage across the first sampling resistor in the sampling loop; the processing module is used to determine the equivalent resistance of the contactor based on the first sampling voltage, the power supply voltage and the first sampling resistor; the processing module is also used to determine the contactor state based on the equivalent resistance and resistance threshold of the contactor, and the resistance threshold is applicable to different voltage platforms.

[0019] In a possible implementation, the sampling circuit also includes a second sampling resistor; the first end of the contactor is connected to the first end of the power supply, the second end of the contactor is connected to the first end of the second sampling resistor, the second end of the second sampling resistor is connected to the first end of the first sampling resistor, and the second end of the first sampling resistor is connected to the second end of the power supply.

[0020] In a possible implementation manner, the processing module is specifically configured to calculate the equivalent resistance Requivalent according to the following formula:

[0021]

[0022] Wherein, U1 is the first sampling voltage, Upack is the power supply voltage, R1 is the first sampling resistor, and R2 is the second sampling resistor.

[0023] In one possible implementation, before determining the contactor state based on the equivalent resistance and resistance threshold of the contactor, the processing module is also used to determine the resistance threshold based on the second sampling voltage and different voltage platforms, where the different voltage platforms are multiple power supply voltages within a voltage value range including the power supply voltage, and the second sampling voltage is determined based on the first sampling voltage, a preset voltage difference, and a preset precision deviation; wherein the preset voltage difference is used to adjust the first sampling voltage when the first sampling voltage and the power supply voltage are not collected synchronously, and is the phase difference voltage of the preset disturbance peak and trough, and the preset precision deviation is the sampling precision deviation corresponding to the collection of the first sampling voltage.

[0024] In a possible implementation manner, the processing module is specifically configured to calculate the second sampling voltage U1′ according to the following formula:

[0025] U1′=(U1+m)*(1+n)%

[0026] Wherein, U1 is the first sampling voltage, m is the preset voltage difference, and n is the preset accuracy deviation.

[0027] In a possible implementation, the processing module is specifically used to obtain multiple predicted resistance thresholds according to the second sampling voltage, different voltage platforms, the first sampling resistor, the second sampling resistor, and a calculation formula for the equivalent resistance; and the smallest predicted resistance threshold among the multiple predicted resistance thresholds is used as the resistance threshold.

[0028] In one possible implementation, the processing module is specifically used to predict the disconnection of the contactor when the equivalent resistance of the contactor is greater than the resistance threshold, and compare it with the disconnection of the contactor in the sampling loop. If the predicted state is the same as the actual control state, it can be determined that the contactor is in a normal disconnected state; or, if the equivalent resistance of the contactor is less than or equal to the resistance threshold, predict the closure of the contactor, and compare it with the disconnection of the contactor in the sampling loop. At this time, the predicted state of the contactor is different from the actual control state, and it is determined that the contactor is in an abnormal closed state, for example, a sintered state, etc.

[0029] In a third aspect, the present application provides an electronic device, which includes a processor and a memory, wherein the memory stores a computer program, and the processor executes the computer program so that the electronic device executes the method described in the first aspect above.

[0030] In a fourth aspect, the present application provides a vehicle, which is used to execute the method described in the first aspect, including the contactor diagnostic device described in the second aspect, or including the electronic device described in the third aspect.

[0031] In a fifth aspect, the present application provides a computer program product comprising instructions, which, when executed by an electronic device, causes the electronic device to execute the method of the first aspect.

[0032] In a sixth aspect, the present application provides a computer-readable storage medium, in which a program is stored. When the program runs on an electronic device, the electronic device executes the method described in the first aspect above.

[0033] Based on the implementations provided in the above aspects, this application can also be further combined to provide more implementations. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for describing the embodiments.

[0035] Figure 1 is a structural schematic diagram of a contactor diagnostic system provided in an embodiment of the present application;

[0036] Figure 2 is a structural schematic diagram of a sampling circuit provided in an embodiment of the present application;

[0037] Figure 3 is a flow chart of a contactor diagnosis method provided by an embodiment of the present application;

[0038] Figure 4 is a structural schematic diagram of a contactor diagnostic device provided in an embodiment of the present application;

[0039] Figure 5 is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application;

[0040] Figure 6 It is a structural schematic diagram of a vehicle provided in an embodiment of the present application. DETAILED DESCRIPTION

[0041] like Figure 1 As shown, Figure 1 1 is a schematic diagram of the structure of a contactor diagnostic system provided by an embodiment of the present application, wherein the contactor detection system includes a sampling circuit 110, a sensor 120 and an electronic device 130. The sensor is used to collect the voltage at a sampling point in the sampling circuit, and send the collected voltage data to the electronic device, so that the electronic device diagnoses the contactor status in the sampling circuit according to the collected data.

[0042] In a possible implementation, the present application takes the system diagnosing the contactor status in the battery pack as an example. In the case of diagnosing the contactor status in the battery pack, the present application provides a structural schematic diagram of a sampling circuit, such as Figure 2 As shown. The sampling circuit includes a power supply 210, a first sampling resistor 220, a second sampling resistor 230 and a contactor 240, wherein the first end of the contactor is connected to the first end of the power supply, the second end of the contactor is connected to the first end of the second sampling resistor, the second end of the second sampling resistor is connected to the first end of the first sampling resistor, and the second end of the first sampling resistor is connected to the second end of the power supply. Since the above sampling circuit is a circuit corresponding to the state of the contactor in the battery pack, the power supply in the sampling circuit is used to supply power to the electrical appliance. In a possible implementation, the first end of the electrical appliance is connected to the second end of the contactor, and the second end of the electrical appliance is connected to the second end of the power supply. Therefore, by determining the state of the contactor in the battery pack, it can be determined whether the battery pack can normally supply power to the electrical appliance.

[0043] In a possible implementation manner, the contactor is used to control the flow of current, and includes a switch and a relay, which is not specifically limited in this application.

[0044] In a possible implementation manner, the contactor diagnostic system provided in the embodiment of the present application can also be applied to other scenarios, for example, a scenario of diagnosing the relay status of the vehicle end, and the sampling circuit corresponding to the scenario is Figure 2 There are certain differences compared to the sampling circuit shown, and the power supply also changes adaptively with different scenarios, which is not specifically limited in this application.

[0045] In a specific implementation, the contactor detection system may include multiple sensors, which are respectively used to collect the power supply voltage and the first sampling voltage corresponding to the two ends of the first sampling resistor. In a possible implementation, the sensor can also be used to collect voltages at more sampling points, as well as different types of parameters such as current and temperature in the battery pack, which is not specifically limited in this application.

[0046] In a specific implementation, the electronic device may be a battery management controller (BMC) for monitoring and managing the battery. Figure 1 The sampling chip 131 and microcontroller 132 (MCU) are shown. The sampling chip is connected to the MCU through a high-reliability data transmission channel to achieve the transmission of instructions and data between the two. The sampling chip is used to obtain the power supply voltage and the first sampling voltage collected by the sensor and transmit them to the MCU. The MCU is used to diagnose the contactor status in the battery pack according to the power supply voltage and the first sampling voltage.

[0047] In a possible implementation manner, the contactor detection system may further include more types and quantities of components, which are not specifically limited in the present application.

[0048] At present, with the increasing awareness of environmental protection and the increasingly serious environmental problems such as global warming, electric vehicles are developing rapidly. In electric vehicles, the contactor controls the power supply of the motor by controlling the connection and disconnection of the battery system and the motor. It plays an important role in the power system or braking system of the vehicle. Therefore, in order to ensure the normal operation of the contactor and the normal operation of the vehicle, it is necessary to diagnose the state of the contactor. In the above-mentioned contactor diagnosis system, a commonly used method is that the electronic device calculates the difference according to the sampled voltage obtained by the sensor at the second end of the contactor and the sampled battery pack voltage, and compares the difference with the set fixed voltage threshold. When the difference is less than the fixed voltage threshold, it is determined that the contactor is stuck, and then the contactor state is judged in combination with the actual control state of the contactor. When the actual control state of the contactor is disconnected, it is determined that the contactor is in a stuck state, and when the actual control state of the contactor is closed, it is determined that the contactor is in a normal closed state. Since it takes a longer time for the voltage to reach the set fixed voltage threshold under low voltage conditions, the above method has the problem of being unable to respond quickly. Furthermore, when the fixed voltage threshold used to determine the contactor status is inaccurate, the above method has the problem of incorrect contactor status judgment.

[0049] Therefore, in order to solve the above problems, the present application provides a contactor diagnosis method, which performs contactor diagnosis and determines the contactor state by comparing the equivalent resistance of the contactor determined according to the first sampling voltage and the size of the resistance threshold, wherein the determination of the resistance threshold takes into account the problems caused by different voltage platforms and voltage fluctuations, and is applicable to different working conditions. Compared with the current method of contactor diagnosis based on sampling voltage and fixed voltage threshold, its judgment condition has stronger robustness, and can be used on different voltage platforms, or in the presence of voltage fluctuations. , The specific process of a contactor diagnosis method provided by the above-mentioned application is as follows.

[0050] like Figure 3 As shown, Figure 3 is a flow chart of a contactor diagnostic method provided in an embodiment of the present application. The contactor diagnostic method is applied to Figure 1 In the contactor diagnostic system shown, the diagnosis of the contactor status in the battery pack is still taken as an example. Since when the contactor in the sampling loop is closed, the equivalent resistance corresponding to both ends of the contactor is close to 0 under different working conditions, the contactor diagnostic method provided in the present application is performed when the contactor in the sampling loop is disconnected, and the method includes the following steps.

[0051] S310: Acquire a first sample voltage and a power supply voltage.

[0052] Obtain a first sampled voltage and a power supply voltage, wherein the first sampled voltage is the voltage obtained by the sensor from Figure 2 The voltage across the first sampling resistor is sampled in the sampling loop shown.

[0053] S320: Determine an equivalent resistance of the contactor according to the first sampled voltage, the power supply voltage, and the first sampled resistance.

[0054] In a possible implementation manner, the equivalent resistance of the contactor is determined according to the first sampled voltage, the power supply voltage, and the first sampled resistance, and the calculation formula is as follows:

[0055]

[0056] Wherein, Requivalent is the equivalent resistance of the contactor, U1 is the first sampling voltage, Upack is the power supply voltage, R1 is the first sampling resistor, and R2 is the second sampling resistor. When the sizes of the first sampling resistor and the second sampling resistor in the sampling loop are known, the equivalent resistance of the contactor can be calculated based on the first sampling voltage obtained from the sensor and the power supply voltage for subsequent diagnosis of the contactor status.

[0057] S330: Determine the contactor state according to the equivalent resistance and resistance threshold of the contactor, wherein the resistance threshold is applicable to different voltage platforms.

[0058] The equivalent resistance of the contactor is calculated by step S320, and the resistance threshold needs to be determined according to the second sampling voltage and different voltage platforms. Among them, different voltage platforms are multiple power supply voltages within the voltage value range including the power supply voltage. For example, when the power supply voltage is 400V, 200V, 300V, 400V, 500V and other different power supply voltages can be taken. In a possible implementation, other power supply voltages of values ​​within the range of 200V to 500V can also be taken. The present application does not specifically limit the values ​​and quantities of different voltage platforms. The simulation of the above-mentioned different voltage platforms is to determine the limit threshold of the resistance, so that the resistance threshold finally determined is more accurate and applicable to different voltage platforms, so that the judgment condition for judging the contactor state according to the resistance threshold has stronger robustness.

[0059] The calculation of the resistance threshold also requires the calculation of the second sampling voltage, which is determined according to the first sampling voltage, the preset voltage difference and the preset accuracy deviation corresponding to different voltage platforms. Among them, in the process of detecting the contactor state of the battery pack, the operation of rapid acceleration or rapid deceleration of the vehicle will cause the current of the battery pack to change sharply, thereby causing the voltage fluctuation on the high-voltage bus. Since the sensor for sampling the first sampling voltage and the power supply voltage is not completely synchronous, and the voltage drop is large when the current changes rapidly, the moment of collecting the first sampling voltage and the moment of collecting the power supply voltage may be out of sync, and there is a problem of inaccurate first sampling voltage. Therefore, when determining the resistance threshold, the present application adopts a preset voltage difference to solve this problem. The preset voltage difference is used to adjust the first sampling voltage when the sensor collects the first sampling voltage and the power supply voltage out of sync, which is the phase difference voltage of the preset disturbance peak and trough. For example, a preset disturbance signal with a maximum value of 10V (peak) and a minimum value of -10V (trough) can be introduced, or a preset disturbance signal with a maximum value of 15V (peak) and a minimum value of -15V (trough) can be introduced, and the present application does not make specific restrictions on this. The preset accuracy deviation is a sampling accuracy deviation corresponding to when the sensor collects the first sampling voltage.

[0060] In the above process of calculating the second sampling voltage, voltage fluctuations, sampling asynchrony and working conditions with sampling accuracy deviation are taken into account. Therefore, the resistance threshold determined according to the second sampling voltage can also adapt to the working conditions of voltage fluctuation sampling asynchrony and sampling accuracy deviation. The resistance threshold is more accurate, thereby making the conditions for judging the contactor state based on the resistance threshold more robust, ensuring that the diagnosis result of the contactor state is more accurate.

[0061] In a specific implementation, the calculation formula of the second sampling voltage is as follows:

[0062] U1′=(U1+m)*(1+n)%

[0063] Among them, U1′ is the second sampling voltage, U1 is the first sampling voltage, m is the preset voltage difference, and n is the preset accuracy deviation. The second sampling voltage calculated by the above formula can cover the working conditions of voltage fluctuation and asynchronous sampling, and takes into account the accuracy deviation of sensor sampling, so that a more accurate resistance threshold can be calculated in the subsequent calculation process.

[0064] In the case of different voltage platforms, the calculated second sampling voltage is different, and there is a one-to-one correspondence between the second sampling voltage and the voltage platform. According to multiple different voltage platforms, the second sampling voltage corresponding to each voltage platform, the calculation formula of the first sampling resistor, the second sampling resistor and the equivalent resistance, multiple predicted resistance thresholds Requivalent' are calculated, and the specific calculation process is as follows:

[0065]

[0066] Among them, Upack′ is a power supply voltage value corresponding to one of a plurality of different voltage platforms, U1′ is a second sampling voltage corresponding to Upack′, R1 is a first sampling resistor, and R2 is a second sampling resistor.

[0067] In a possible implementation, in the above-mentioned calculation process, a sampling accuracy deviation can also be set for the first sampling voltage and the power supply voltage. For example, the accuracy deviations in two different directions are determined, the power supply voltage is set to a positive deviation, that is, when collecting the power supply voltage, the value is taken in the direction of a larger numerical value, and the first sampling voltage is set to a negative deviation, that is, when collecting the first sampling voltage at the sampling point, the value is taken in the direction of a smaller numerical value. There may also be other sampling accuracy deviation settings, which are not specifically limited in this application.

[0068] When the predicted resistance thresholds corresponding to the worst operating conditions of multiple different voltage platforms are calculated, the smallest predicted resistance threshold is selected as the resistance threshold. The above process can ensure that the resistance threshold finally determined for contactor status diagnosis is adaptable to multiple different voltage platforms and operating conditions such as asynchronous voltage fluctuation sampling, thereby solving the problem that the current use of a fixed voltage threshold for contactor status diagnosis is not suitable for operating conditions such as voltage fluctuations, and avoiding diagnostic errors caused by asynchronous voltage fluctuation sampling.

[0069] When the equivalent resistance and the resistance threshold of the contactor are determined, the equivalent resistance and the resistance threshold of the contactor are compared, and the contactor diagnosis result is determined in combination with the disconnection of the contactor in the current sampling loop.

[0070] In one possible implementation, when the equivalent resistance of the contactor is greater than the resistance threshold, it is determined that the contactor is disconnected, which is the same as the case where the contactor is disconnected in the sampling loop, and the contactor is determined to be in a normal disconnected state; or, when the equivalent resistance of the contactor is less than or equal to the resistance threshold, it is determined that the contactor is closed, which is different from the case where the contactor is disconnected in the sampling loop, and the contactor is determined to be in an abnormal sintering state.

[0071] In a possible implementation, when the contactor is closed, the corresponding resistance threshold can also be calculated according to the above method for calculating the second sampled voltage and predicting the resistance threshold, which will not be described in detail here. The specific diagnostic process is that when the equivalent resistance of the contactor is greater than the resistance threshold, it is determined that the contactor is disconnected, which is different from the current closed state of the contactor, and the contactor is determined to be in an abnormal disconnected state. When the equivalent resistance of the contactor is less than or equal to the resistance threshold, it is determined that the contactor is closed, which is the same as the actual control state of the current contactor, and the contactor is determined to be in a normal closed state.

[0072] In a specific implementation, the first sampling resistor in the sampling loop is 2kΩ, the second sampling resistor is 264kΩ, the power supply voltage is 500V, and the predetermined resistance threshold is 31kΩ. At this time, the contactor in the sampling loop is kept disconnected, the sensor collects the voltage of the first end of the first sampling resistor and the value of the power supply voltage under real-time working conditions, and the electronic device calculates the equivalent resistance of the current contactor based on the acquired first sampling voltage and power supply voltage. When the equivalent resistance is less than 31kΩ, the contactor is judged to be closed, and it is determined that the judged contactor state is different from the actual control state of the contactor disconnection, and it is determined that the contactor has abnormal closing conditions such as adhesion.

[0073] In the above process, the embodiment of the present application takes the detection of the contactor status in the battery pack as an example to explain the contactor diagnosis method in detail. In a possible implementation, the contactor diagnosis method provided by the present application can also be applied to the diagnosis of switch and relay status in more scenarios, such as the diagnosis of vehicle-side relays, etc., which is not specifically limited in the present application. When the contactor diagnosis method is used to diagnose the vehicle-side relay, the power supply used in the sampling circuit will be adaptively changed, and the actual connection in the sampling circuit will also be adaptively modified, which is not described in detail in the present application.

[0074] In summary, the contactor diagnosis method provided in the embodiment of the present application performs contactor diagnosis by comparing the equivalent resistance of the contactor and the resistance threshold, replacing the current diagnostic method of comparing a fixed voltage threshold with the difference determined according to the sampled voltage and the power supply voltage, wherein the resistance threshold takes into account the influence of different voltage platforms, voltage fluctuations and other working conditions during the determination process, thereby ensuring a rapid response of the contactor diagnosis, and the diagnostic conditions for determining the contactor status according to the resistance threshold have better robustness, thereby improving the accuracy of the contactor diagnosis.

[0075] like Figure 4 As shown, Figure 4 This is a schematic diagram of the structure of a contactor diagnostic device provided by the present application. The contactor diagnostic device can be applied to Figure 1 In the electronic device shown, the contactor diagnostic device 400 includes an acquisition module 410 and a processing module 420. The acquisition module is used to acquire a first sampled voltage and a power supply voltage, wherein the first sampled voltage is the voltage across a first sampled resistor in a sampling loop; the processing module is used to determine the equivalent resistance of the contactor according to the first sampled voltage, the power supply voltage and the first sampled resistor; the processing module is also used to determine the contactor state according to the equivalent resistance and the resistance threshold of the contactor, and the resistance threshold is applicable to different voltage platforms.

[0076] In the specific implementation, the acquisition module is used to execute Figure 3 In step S310 shown in FIG. 1 , the processing module is used to execute Figure 3 In a possible implementation manner, the acquisition module and the processing module may also perform more steps, which are not specifically limited in this application.

[0077] like Figure 5 As shown, Figure 5 1 is a schematic diagram of the structure of an electronic device provided in the present application, wherein the electronic device 130 includes a processor 510, a memory 520, a communication interface 530 and a bus 540. The processor, the memory and the communication interface may be interconnected through an internal bus or may communicate through wireless transmission or other means.

[0078] The processor 510 may be composed of at least one general-purpose processor, such as a central processing unit (CPU), or a combination of a CPU and a hardware chip. The processor 510 is used to execute various types of digital storage instructions. The processor can implement Figure 3 Any step in the diagram shown.

[0079] The memory 520 may be a volatile memory, such as a random access memory, a dynamic random access memory, a static random access memory, a synchronous dynamic random access memory, etc. The memory may also include a combination of the above types. The memory 520 may include programs and data. The processor 510 may execute program codes to execute Figure 3 In the steps shown, the memory can also store multiple first sampling voltages, power supply voltages, calculated equivalent resistances, resistance thresholds, etc., which are not specifically limited in this application.

[0080] The communication interface 530 can be used to receive the first sampled voltage, power supply voltage, etc. obtained by sensor sampling, and send the contactor state judgment result to the user, which is not specifically limited in this application.

[0081] It should be noted that Figure 5 This is only a possible implementation of the embodiment of the present application. In actual applications, the electronic device may also include more or fewer components, which is not limited here.

[0082] like Figure 6 As shown, Figure 6 is a schematic diagram of a vehicle structure provided by an embodiment of the present application. The vehicle 600 may include a contactor diagnostic device 400, which performs Figure 3 All the steps shown in the figure, the specific structure of the contactor diagnostic device is as follows Figure 4In a possible implementation manner, the vehicle may include more or fewer components, which is not specifically limited in this application.

[0083] The embodiment of the present application further provides a computer-readable storage medium, in which instructions are stored. When the instructions are executed on a processor, Figure 3 The method flow shown is realized.

[0084] The embodiment of the present application further provides a computer program product. When the computer program product is run on a processor, Figure 3 The method flow shown is realized.

[0085] The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present invention, and these modifications or replacements should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A contactor diagnostic method, characterized in that: In the event that a contactor in the sampling loop is disconnected, the method comprises: Acquire a first sampling voltage and a power supply voltage, wherein the first sampling voltage is a voltage across a first sampling resistor in the sampling loop; Determining an equivalent resistance of a contactor according to the first sampled voltage, the power supply voltage and the first sampled resistance; The contactor state is determined according to the equivalent resistance and resistance threshold of the contactor, wherein the contactor state includes a normal open state and an abnormal closed state, and the resistance threshold is determined according to different voltage platforms.

2. The method according to claim 1, characterized in that The sampling circuit also includes a second sampling resistor; The first end of the contactor is connected to the first end of the power supply, the second end of the contactor is connected to the first end of the second sampling resistor, the second end of the second sampling resistor is connected to the first end of the first sampling resistor, and the second end of the first sampling resistor is connected to the second end of the power supply.

3. The method according to claim 2, characterized in that The equivalent resistance of the contactor is determined according to the first sampling voltage, the power supply voltage and the first sampling resistance, and the calculation formula is as follows: Wherein, Requivalent is the equivalent resistance of the contactor, U1 is the first sampling voltage, Upack is the power supply voltage, R1 is the first sampling resistor, and R2 is the second sampling resistor.

4. The method according to any one of claims 1 to 3, characterized in that Before determining the contactor state according to the equivalent resistance and the resistance threshold of the contactor, the method further includes: The resistance threshold is determined according to the second sampling voltage and the different voltage platforms, wherein the different voltage platforms are multiple power supply voltages within a voltage value range including the power supply voltage, and the second sampling voltage is determined according to the first sampling voltage, a preset voltage difference and a preset precision deviation; wherein the preset voltage difference is used to adjust the first sampling voltage when the first sampling voltage and the power supply voltage are not collected synchronously, and is a phase difference voltage of a preset disturbance peak and trough, and the preset precision deviation is a sampling precision deviation corresponding to the collection of the first sampling voltage.

5. The method according to claim 4, characterized in that The calculation formula of the second sampling voltage is as follows: U1 ′ =(U1+m)*(1+n)% Among them, U1 ′ is the second sampling voltage, U1 is the first sampling voltage, m is the preset voltage difference, and n is the preset accuracy deviation.

6. The method according to claim 5, characterized in that The determining the resistance threshold according to the second sampled voltage and the different voltage platforms comprises: Obtaining a plurality of predicted resistance thresholds according to the second sampling voltage, the different voltage platforms, the first sampling resistor, the second sampling resistor, and a calculation formula of the equivalent resistance; The smallest predicted resistance threshold among the multiple predicted resistance thresholds is used as the resistance threshold.

7. The method according to claim 6, characterized in that Determining the contactor state according to the equivalent resistance and the resistance threshold of the contactor includes: When the equivalent resistance of the contactor is greater than the resistance threshold, predict that the contactor is disconnected, and compare with the disconnection of the contactor in the sampling loop to determine that the contactor is in a normal disconnection state; or When the equivalent resistance of the contactor is less than or equal to the resistance threshold, it is predicted that the contactor is closed, and compared with the disconnection of the contactor in the sampling loop, it is determined that the contactor is in an abnormal closed state.

8. A contactor diagnostic device, characterized in that: In case the contactor in the sampling loop is disconnected, the device comprises an acquisition module and a processing module: The acquisition module is used to acquire a first sampling voltage and a power supply voltage, wherein the first sampling voltage is a voltage across a first sampling resistor in the sampling loop; The processing module is used to determine the equivalent resistance of the contactor according to the first sampled voltage, the power supply voltage and the first sampled resistance; The processing module is further used to determine the contactor state according to the equivalent resistance and resistance threshold of the contactor, and the resistance threshold is applicable to different voltage platforms.

9. An electronic device, characterized in that: The electronic device comprises a processor and a memory, wherein the memory stores a computer program, and the processor executes the computer program so that the electronic device performs the method according to any one of claims 1 to 7.

10. A vehicle, characterized in that: The vehicle includes the contactor diagnostic device according to claim 8, or the electronic device according to claim 9.

11. A computer program product comprising instructions, characterized in that When the instructions are executed by a computing device, the electronic apparatus is caused to perform the method according to any one of claims 1 to 7.

12. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a program, and when the program is executed on a computing device, the electronic apparatus executes the method according to any one of claims 1 to 7.

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