Switching tube fault detection method and device, storage medium and electronic equipment

Abstract

The invention discloses a switch tube fault detection method and device, a storage medium and electronic equipment, and belongs to the technical field of switch tube fault detection.The switch tube fault detection method comprises the steps that a charging switch and a discharging switch are driven to be switched on and switched off, and whether a switch circuit is in different states or not is obtained; an intermediate point voltage between the charging switch and the discharging switch, a switch driving voltage of the charging switch and the discharging switch, and an output end positive electrode voltage; according to the intermediate point voltage, the switch driving voltage and the output end positive electrode voltage, voltage differences between the intermediate point voltage and the switch driving voltage and between the intermediate point voltage and the output end positive electrode voltage are obtained; and determining whether the charging switch and / or the discharging switch has a fault according to the intermediate point voltage and the voltage difference. A charging switch and a discharging switch are driven to be switched on and switched off, intermediate point voltage, switch driving voltage and output end positive electrode voltage are collected, and voltage difference value operation and threshold value comparison are combined, so that fault judgment of the charging switch and the discharging switch is achieved.

Description

Technical Field

[0001] This application relates to the field of switching transistor fault detection technology, and in particular to a switching transistor fault detection method, detection device, storage medium and electronic device. Background Technology

[0002] Low-voltage lithium batteries, with their significant advantages such as environmental friendliness, high energy efficiency, and long cycle life, have gradually replaced traditional lead-acid batteries and are widely used in the low-voltage power supply systems of electric vehicles. In the main circuit of a low-voltage lithium battery, the MOS circuit is the core component for realizing circuit on / off control. The stability of its operating state directly affects the reliable operation of the entire low-voltage power supply system. Therefore, fault diagnosis of the MOS is one of the key functions of the low-voltage lithium battery management system.

[0003] In related technologies, the MOS control hardware circuit architecture adopted by various companies differs, resulting in a lack of universality in the corresponding fault diagnosis strategies. Moreover, the diagnosis solutions often require the configuration of complex dedicated detection circuits and matching with exclusive detection methods adapted to these circuits. This not only increases the hardware cost and design complexity of the system but also makes the diagnosis process cumbersome and inefficient, making it difficult to meet the high-efficiency diagnosis requirements in the large-scale application scenarios of low-voltage lithium batteries. Summary of the Invention

[0004] This application provides a method, device, storage medium, and electronic device for detecting switching transistor faults, in order to at least partially solve the above-mentioned technical problems.

[0005] To achieve the above objectives, according to a first aspect of this application, a method for detecting switch transistor faults is provided, applied to a switching circuit of a battery system. The switching circuit is connected between the positive terminal of the battery pack and the positive terminal of the output terminal. The switching circuit includes a charging switch and a discharging switch. The method for detecting switch transistor faults includes: S1. Drive the charging switch and the discharging switch to switch on and off, and obtain the midpoint voltage between the charging switch and the discharging switch, the switching drive voltage of the charging switch and the positive voltage of the output terminal of the discharging switch when the switching circuit is in different states; In some cases, based on pre-set fault detection requirements, such as diagnosing jamming faults in the closed state and adhesion faults in the open state, the control module sends instructions to the drive circuit to drive the charging switch and discharging switch to the target on / off state. Then, it collects the intermediate point voltage, switch drive voltage and output positive voltage to provide raw data support for subsequent fault determination.

[0006] S2. Based on the midpoint voltage, the switch drive voltage, and the positive output voltage, obtain the voltage difference between the midpoint voltage and the switch drive voltage and the positive output voltage, respectively. In some examples, based on the voltage signal acquired by S1, the data processing is performed by the arithmetic unit of the control module to calculate two sets of voltage differences: the difference between the intermediate point voltage and the switch drive voltage, and the difference between the intermediate point voltage and the positive voltage of the output terminal. The acquired voltage signal is converted into a relative value signal reflecting the degree of state matching, providing a quantifiable basis for subsequent threshold comparison.

[0007] S3. Determine whether the charging switch and / or discharging switch are faulty based on the midpoint voltage and voltage difference.

[0008] In some examples, the intermediate point voltage collected by S1 and the two voltage differences calculated by S2 are compared with corresponding preset thresholds. The duration of the comparison results, combined with the voltage signal duration, avoids transient interference and ensures reliable judgment, determining whether the charging switch and / or discharging switch meet preset fault characteristics. If the comparison results meet the fault judgment conditions, the corresponding fault type is determined. If all comparison results meet the normal state standards, the switching transistor is determined to be fault-free.

[0009] Optionally, driving the charging switch and discharging switch to switch on and off includes: S101, Control the charging switch and discharging switch to close synchronously; In some cases, when it is necessary to detect whether the charging switch or discharging switch is stuck, the control module sends a synchronous closing command to the drive circuit, driving the charging switch and discharging switch to switch to the closed state at the same time, ensuring that the two switches are in the same target operating state, laying the foundation for subsequent determination of the stuck fault by comparing voltage signals.

[0010] Determining whether the charging switch and / or the discharging switch is faulty based on the intermediate point voltage and the voltage difference includes: S301. Determine whether the switching transistor drive is abnormal based on whether the first voltage difference between the intermediate point voltage and the switch drive voltage is less than the first threshold. In some cases, based on the intermediate point voltage and switch drive voltage collected by S1, a first voltage difference between the two is calculated and compared with a first threshold. If the first voltage difference is less than the first threshold, it indicates that the drive signal has not effectively driven the switch to the expected operating state, and the switch drive is determined to be abnormal; if the first voltage difference is not less than the first threshold, it indicates that the drive signal matches the actual response of the switch, and the switch drive is determined to be normal.

[0011] S302. Determine whether the discharge switch is stuck based on whether the intermediate point voltage is less than or equal to the second threshold. In some cases, the intermediate point voltage collected by S1 is compared with the second threshold. If the intermediate point voltage is greater than the second threshold, it indicates that the discharge switch has been successfully closed without any jamming fault; if the intermediate point voltage is not greater than the second threshold, it indicates that the discharge switch has not closed normally as instructed, and there is a jamming fault.

[0012] S303. Determine whether the charging switch is stuck based on whether the second voltage difference between the midpoint voltage and the positive voltage at the output terminal is greater than the third threshold.

[0013] In some cases, the second voltage difference between the midpoint voltage collected by S1 and the positive voltage at the output terminal is calculated and compared with a third threshold. If the second voltage difference is greater than the third threshold, it indicates that the charging switch is not effectively turned on and there is a jamming fault; if the second voltage difference is not greater than the third threshold, it indicates that the charging switch is normally turned on and there is no jamming fault.

[0014] Optionally, determining whether the switch drive is abnormal based on whether the first voltage difference between the intermediate point voltage and the switch drive voltage is less than the first threshold includes: S3011. When the first voltage difference between the intermediate point voltage and the switch drive voltage is less than the first threshold, control the charging switch and the discharging switch to close synchronously for a first preset time. If the first voltage difference is still less than the first threshold, determine that the switch drive is abnormal. In some cases, when the preset fault detection item is jamming detection, the control module sends a synchronous closing command to the drive circuit, driving the charging switch and the discharging switch to enter the closed state simultaneously, and maintaining this closed state for a first preset time. After the switching transistor's operating state stabilizes, the intermediate point voltage, switch drive voltage, and output positive terminal voltage are then collected to ensure that the collected voltage signals can accurately reflect the actual operating state of the switching transistor, thus improving the accuracy of the switching transistor drive anomaly detection.

[0015] Determining whether the discharge switch is stuck based on whether the intermediate point voltage is less than or equal to the second threshold includes: S3021. When the intermediate point voltage is greater than the second threshold, control the charging switch and the discharging switch to close synchronously for the second preset time. If the intermediate point voltage is still less than or equal to the second threshold, determine that the discharging switch is stuck. In some cases, when the preset fault detection item is jamming detection, the control module sends a synchronous closing command to the drive circuit, driving the charging switch and the discharging switch to simultaneously enter the closed state and maintain this closed state for a second preset time. After the switching transistor's operating state stabilizes, the intermediate point voltage, switch drive voltage, and output positive terminal voltage are then collected to ensure that the collected voltage signals can accurately reflect the actual operating state of the switching transistor and improve the accuracy of the discharge switch jamming fault determination.

[0016] Determining whether the charging switch is stuck based on whether the second voltage difference between the intermediate point voltage and the positive voltage at the output terminal is greater than the third threshold includes: S3031. When the second voltage difference between the intermediate point voltage and the positive voltage of the output terminal is greater than the third threshold, control the charging switch and the discharging switch to close synchronously for a third preset time. If the second voltage difference between the intermediate point voltage and the positive voltage of the output terminal is still greater than the third threshold, determine that the charging switch is stuck.

[0017] In some cases, when the preset fault detection item is jamming detection, the control module sends a synchronous closing command to the drive circuit, driving the charging switch and the discharging switch to enter the closed state simultaneously, and maintaining this closed state for a third preset time. After the switching transistor's operating state stabilizes, the intermediate point voltage, switch drive voltage, and output positive terminal voltage are then collected to ensure that the collected voltage signals can accurately reflect the actual operating state of the switching transistor, thereby improving the accuracy of charging switch jamming fault determination.

[0018] Optionally, when the first voltage difference between the intermediate point voltage and the switch drive voltage is less than the first threshold, the charging switch and the discharging switch are controlled to close synchronously for a first preset time. If the first voltage difference is still less than the first threshold, a switch drive abnormality is determined, including: S3012. When the first voltage difference between the intermediate point voltage and the switch drive voltage is less than the first threshold, control the charging switch and the discharging switch to open synchronously and then close synchronously. Repeat this process N times. If the first voltage difference is still less than the first threshold, then determine that the switch drive is abnormal. N is an integer greater than 1. In some cases, when the first voltage difference between the intermediate point voltage and the switch drive voltage is detected to be less than a first threshold, the control module first drives the charging switch and the discharging switch to open synchronously. After a preset delay to ensure that the switching transistor is completely disconnected, it then drives them to close synchronously. After the state stabilizes, the first voltage difference is detected again. This cycle of opening and closing is repeated a preset number of times. If the first voltage difference is still less than the first threshold, the switch drive is determined to be abnormal. If the first voltage difference recovers to a level not less than the first threshold during the cycle, it is determined to be a transient interference, and the drive abnormality fault is eliminated.

[0019] When the intermediate point voltage is greater than the second threshold, the charging switch and the discharging switch are controlled to close synchronously for the second preset time. If the intermediate point voltage is still less than or equal to the second threshold, it is determined that the discharging switch is stuck, including: S3022. When the intermediate point voltage is greater than the second threshold, control the charging switch and the discharging switch to open synchronously and then close synchronously. Repeat this process M times. If the intermediate point voltage is still greater than the second threshold, then determine that the discharging switch is stuck. M is an integer greater than 1.

[0020] In some cases, when the acquired intermediate-point voltage exceeds the second threshold, the control module initiates a cyclic detection process. First, it controls the charging and discharging switches to open synchronously and maintain this for a preset delay. Then, it controls them to close synchronously and stabilize for a period of time before re-acquiring the intermediate-point voltage. If the intermediate-point voltage remains above the second threshold after this cyclic action is repeated a preset number of times, a jamming fault in the discharging switch is confirmed. If the intermediate-point voltage recovers to a level not exceeding the second threshold during the cycle, it indicates that the switching transistor can respond normally to commands, thus eliminating the jamming fault.

[0021] Optionally, when the first voltage difference is less than the first threshold, the charging switch and the discharging switch are controlled to open synchronously and then close synchronously. After repeating this process N times, if the first voltage difference is still less than the first threshold, then the switching transistor is determined to be driving abnormally, where N is an integer greater than 1, including: S3013. When the first voltage difference is less than the first threshold, control the charging switch and the discharging switch to open synchronously and continue for a fourth preset time, then close synchronously and continue for a fifth preset time. Repeat this process multiple times. If the first voltage difference is still less than the first threshold, then determine that the switch drive is abnormal.

[0022] In some cases, when the first voltage difference between the intermediate point voltage and the switch drive voltage is less than the first threshold, the control module first sends a synchronous disconnect command to drive the charging switch and the discharging switch to disconnect simultaneously, and maintains this disconnected state for a fourth preset time to ensure that the switching transistor is completely disconnected from the conduction state, the residual energy of the circuit is completely released, and the accuracy of subsequent voltage acquisition and fault determination is guaranteed.

[0023] In some cases, after the synchronous disconnection of S3013 and the stabilization of the fourth preset time, the control module sends a synchronous closing command to drive the charging switch and the discharging switch to close simultaneously, and maintains the closed state for the fifth preset time. After the switching transistor is stable and the circuit voltage distribution is balanced, the relevant voltage signals are collected and compared to provide accurate data support for fault diagnosis.

[0024] Optionally, when the intermediate point voltage is greater than the second threshold, the charging switch and the discharging switch are controlled to open synchronously and then close synchronously. After repeating this process M times, if the intermediate point voltage is still greater than the second threshold, it is determined that the discharging switch is stuck, where M is an integer greater than 1, including: S3023. When the intermediate point voltage is greater than the second threshold, control the charging switch and the discharging switch to open synchronously and continue for a sixth preset time, then close synchronously and continue for a seventh preset time. If the intermediate point voltage is still greater than the second threshold after repeating this process multiple times, then it is determined that the discharging switch is stuck.

[0025] In some cases, when the midpoint voltage is detected to be greater than the second threshold, the control module first sends a synchronous disconnect command to drive the charging switch and the discharging switch to disconnect simultaneously, and maintains the disconnected state for a sixth preset time to ensure that the switching transistor is completely disconnected from the conducting state, the residual energy of the circuit is fully released, and the accuracy of subsequent voltage acquisition and fault determination is guaranteed.

[0026] In some cases, after the synchronous disconnection of S3023 and the stabilization of the sixth preset time, the control module sends a synchronous closing command to drive the charging switch and the discharging switch to close simultaneously, and maintains the closed state for the seventh preset time. After the switching transistor is stable and the circuit voltage distribution is balanced, the relevant voltage signals are collected and compared to provide accurate data support for fault diagnosis.

[0027] Optionally, controlling the charging switch and discharging switch to close synchronously includes: S100, the battery system is powered on and woken up, performs a self-test and finds no faults, and controls the switching circuit to be in a discharging state, initializing the number of synchronous disconnections and synchronous closures.

[0028] In some cases, when the low-voltage lithium battery management system is powered on and woken up, it first completes a self-test of its core components. When it confirms that there is no basic fault and the system is in a discharging state, the control module initializes the counting parameters for synchronous disconnection and synchronous closure. Then, it sends a command to the drive circuit to control the charging switch and discharging switch to switch to the closed state synchronously, thus formally starting the jamming detection process and laying the foundation for subsequent determination of jamming faults by comparing voltage signals.

[0029] Optionally, driving the charging switch and discharging switch to switch on and off includes: S102, Control the charging switch and discharging switch to disconnect synchronously; In some cases, when it is necessary to detect whether the charging switch or discharging switch has a sticking fault, the control module sends a synchronous disconnect command to the drive circuit, driving the charging switch and discharging switch to switch to the disconnect state at the same time, ensuring that the two switching transistors are in the same target operating state, creating conditions for subsequent determination of sticking faults by comparing voltage signals.

[0030] Determining whether the charging switch and / or the discharging switch is faulty based on the intermediate point voltage and the voltage difference includes: S304, determining whether the switch drive is abnormal based on whether the intermediate point voltage is greater than the fourth threshold. In some cases, after the charging and discharging switches are simultaneously disconnected and the circuit stabilizes, the intermediate point voltage is collected and compared with a fourth threshold. If the intermediate point voltage is greater than the fourth threshold, it indicates that the drive signal is not effectively applied to the switching transistor, and the switching transistor drive is preliminarily determined to be abnormal; if the intermediate point voltage is not greater than the fourth threshold, it indicates that the drive signal matches the disconnected state of the switching transistor, and the drive state is normal.

[0031] S305. Determine whether the switch drive is abnormal or the charging switch and the discharging switch are stuck together based on whether the first voltage difference between the intermediate point voltage and the switch drive voltage is greater than a first threshold.

[0032] In some cases, after calculating the first voltage difference between the intermediate point voltage and the switch drive voltage, it is compared with a first threshold. Based on the preliminary judgment result of S304, if the first voltage difference is greater than the first threshold and S304 determines that the drive is normal, it indicates that the switch transistor did not respond to the disconnect command, confirming that the charging switch and the discharging switch are stuck together; if the first voltage difference is greater than the first threshold and S304 determines that the drive is abnormal, it is determined that the abnormal state is caused by an abnormal switch transistor drive; if the first voltage difference is not greater than the first threshold, it indicates that the switch transistor is in normal state and there is no sticking fault.

[0033] Optionally, determining whether the switch drive is abnormal based on whether the intermediate point voltage is greater than the fourth threshold includes: S3041, when the intermediate point voltage is greater than the fourth threshold, controlling the charging switch and the discharging switch to be synchronously disconnected for an eighth preset time; if the intermediate point voltage is still greater than the fourth threshold, determining whether the switch drive is abnormal or the charging switch and the discharging switch are stuck based on whether the first voltage difference between the intermediate point voltage and the switch drive voltage is greater than the first threshold; if the intermediate point voltage is less than or equal to the fourth threshold, continuing to determine whether the switch drive is abnormal based on whether the intermediate point voltage is greater than the fourth threshold.

[0034] In some cases, when the voltage difference between the intermediate point voltage and the switch drive voltage is detected to be greater than the fourth threshold, it indicates that the current drive signal may not be effectively applied to the switch. The control module will control the charging switch and the discharging switch to continue to remain in a synchronously disconnected state, and maintain this state for more than the eighth preset time. This ensures that the switch is completely disconnected and the residual voltage in the circuit is completely released before subsequent voltage detection or fault determination is performed, thereby improving the accuracy of drive state determination.

[0035] In some cases, when the intermediate point voltage is detected to be greater than the fourth threshold, the control module controls the charging switch and discharging switch to remain synchronously disconnected for a period of time up to the eighth preset time. After the circuit state is completely stable, the intermediate point voltage is collected again. If the intermediate point voltage collected again is still greater than the fourth threshold, the first voltage difference between the intermediate point voltage and the switch drive voltage is calculated and compared with the first threshold to determine whether the switch drive is abnormal or the charging switch and discharging switch are stuck together. If the intermediate point voltage collected again is less than or equal to the fourth threshold, the intermediate point voltage is compared with the fourth threshold again to determine whether the switch drive is abnormal.

[0036] Optionally, controlling the charging switch and discharging switch to disconnect synchronously includes: S1021. When the system is in normal operation, control the charging switch and the discharging switch to disconnect synchronously; In some cases, when the system is in a normal charging and discharging state without other fault alarms, the control module sends a synchronous disconnect command to the drive circuit according to the adhesion detection requirements, driving the charging switch and the discharging switch to switch to the disconnect state at the same time, providing a detection environment for subsequent determination of adhesion faults by comparing voltage signals.

[0037] S1022. When the system is in a sleep-wake state, confirm that the charging switch and the discharging switch are disconnected synchronously.

[0038] In some cases, after the system is woken up from sleep mode, the control module does not immediately send on / off commands, but directly collects voltage signals related to the switch state through the sampling unit to confirm whether the charging switch and discharging switch are in the off state.

[0039] Optionally, the charging switch and discharging switch are switched on and off according to the preset fault detection items, and the midpoint voltage between the charging switch and the discharging switch, the switch driving voltage and the positive voltage of the output terminal are obtained, including: S103, obtaining the midpoint voltage of each pair of charging switches and each pair of charging switches in the multiple pairs of charging switches.

[0040] In some cases, according to the requirements of the preset fault detection items, after the control module drives all charging switches and discharging switches to perform on and off actions synchronously, it collects the voltage at the midpoint between each pair of charging switches and discharging switches through the sampling unit corresponding to each midpoint. At the same time, it collects the switch drive voltage and the positive voltage of the output terminal shared by all switches, providing independent and comprehensive voltage data support for subsequent determination of the fault status of each pair of switches.

[0041] According to a second aspect of this disclosure, a switching transistor fault detection device is provided, comprising a driving module, a parameter acquisition module, a processing module, and a determination module. The driving module is used to drive a charging switch and a discharging switch to switch on and off. The parameter acquisition module is used to acquire the intermediate point voltage, the switch driving voltage, and the positive output voltage between the charging switch and the discharging switch. The processing module is used to obtain the voltage difference between the intermediate point voltage and the switch driving voltage and the positive output voltage, respectively, based on the intermediate point voltage, the switch driving voltage, and the positive output voltage. The determination module is used to compare the intermediate point voltage and the voltage difference with a preset threshold to determine whether the charging switch and / or the discharging switch has malfunctioned.

[0042] In some embodiments, the collaborative work of the driving module, parameter acquisition module, processing module, and determination module enables automated detection of charging and discharging switch faults. The modules have clearly defined roles and seamless integration, allowing for rapid and accurate identification of fault types such as abnormal switching transistor drive, jamming, and sticking, thereby improving the safety and reliability of the low-voltage lithium battery system.

[0043] According to a third aspect of this disclosure, a storage medium is provided having a computer program stored thereon, which, when run on a computer, causes the computer to perform the above-described switching transistor fault detection method.

[0044] This application also proposes a storage medium storing a computer program thereon. When the computer program is run on a computer, it causes the computer to execute the above-described switching transistor fault detection method. The specific structure of the switching transistor fault detection method is as described in the above embodiments. Since this storage medium adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be elaborated here.

[0045] According to a fourth aspect of this disclosure, an electronic device is provided, including a processor and a memory, wherein the memory has a computer program, and the processor executes the above-described switching transistor fault detection method by calling the computer program. The specific structure of this switching transistor fault detection method is as described in the above embodiments. Since this electronic device adopts all the technical solutions of all the above embodiments, it possesses at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be elaborated upon here.

[0046] In the switching transistor fault detection method of this application embodiment, the switching circuit is in a discharging or charging state by driving the charging switch and discharging switch on and off. The method collects the intermediate point voltage, the switch driving voltage, and the positive terminal voltage of the output terminal. By combining voltage difference calculation with threshold comparison, it achieves accurate determination of faults such as abnormal driving, jamming, and sticking of the charging and discharging switches. By eliminating the need for additional complex detection circuitry, the detection logic simplifies the switching transistor fault detection process in the battery system, reducing the cost of system hardware design and operation maintenance. By setting voltage parameters as the quantitative judgment standard, the objectivity and reliability of fault detection results are improved, false judgments are reduced, and the stable operation of the battery system is ensured.

[0047] Other features and advantages of this application will be described in detail in the following detailed description section. Attached Figure Description To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0048] To gain a more complete understanding of this application and its beneficial effects, the following description will be provided in conjunction with the accompanying drawings, wherein the same reference numerals in the following description denote the same parts.

[0049] Figure 1 This is a schematic flowchart of the first method for detecting switching transistor faults provided in the embodiments of this application; Figure 2 This is a circuit connection diagram for switching transistor fault detection provided in an embodiment of this application; Figure 3 This is a schematic diagram of the second process of the switching transistor fault detection method provided in the embodiments of this application; Figure 4 This is a flowchart illustrating step S1011 provided in an embodiment of this application; Figure 5 This is a flowchart illustrating step S1021 provided in an embodiment of this application; Figure 6 This is a flowchart illustrating step S1031 provided in an embodiment of this application; Figure 7 This is a flowchart illustrating step S3012 provided in an embodiment of this application; Figure 8 This is a flowchart illustrating step S3022 provided in an embodiment of this application; Figure 9This is a flowchart illustrating steps S3013 and S3014 provided in an embodiment of this application; Figure 10 This is a flowchart illustrating steps S3023 and S3024 provided in the embodiments of this application; Figure 11 This is a flowchart illustrating step S100 provided in an embodiment of this application; Figure 12 This is a schematic diagram of the third process of the switching transistor fault detection method provided in the embodiments of this application; Figure 13 This is a flowchart illustrating step S3041 provided in an embodiment of this application; Figure 14 This is a flowchart illustrating steps S1021 and S1022 provided in the embodiments of this application; Figure 15 This is a flowchart illustrating step S103 provided in an embodiment of this application; Figure 16 This is a circuit block diagram of a switching transistor fault detection device provided in an embodiment of this application.

[0050] Explanation of reference numerals in the attached figures: 401. Driver module; 402. Parameter acquisition module; 403. Processing module; 404. Determination module. Detailed Implementation

[0051] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the protection scope of this application.

[0052] According to the first aspect of this application, referring to Figure 1 This disclosure provides a method for detecting switching transistor faults, applied to the switching circuit of a battery system. The switching circuit is connected between the positive terminal of the battery pack and the positive terminal of the output terminal. The switching circuit includes a charging switch and a discharging switch. The method for detecting switching transistor faults includes: S1. Drive the charging switch and the discharging switch to switch on and off, and obtain the midpoint voltage between the charging switch and the discharging switch, the switching drive voltage of the charging switch and the positive voltage of the output terminal when the switching circuit is in different states. Understandably, preset fault detection items are predefined fault types that need to be diagnosed, such as abnormal switch drive, switch jamming, switch sticking, etc., corresponding to the target on / off state of the corresponding switching transistor, closed or open, which serves as the basis for fault detection. (Refer to...) Figure 2Charging and discharging switches are switching elements in the main circuit of a low-voltage lithium battery that control the on / off state of the charging and discharging circuits, such as MOSFETs. They work together to control the switching circuit. The intermediate point voltage is the voltage at the node between the charging and discharging switches; the switch drive voltage is the control voltage output from the drive circuit to the switching transistor; the positive output voltage is the reference voltage at a specific terminal of the switching transistor, and the positive output voltage (KL30) of both the charging and discharging switches.

[0053] In some cases, based on pre-set fault detection requirements, such as diagnosing jamming faults in the closed state and adhesion faults in the open state, the control module sends instructions to the drive circuit to drive the charging switch and discharging switch to the target on / off state. Then, it collects the intermediate point voltage, switch drive voltage and output positive voltage to provide raw data support for subsequent fault determination.

[0054] S2. Based on the midpoint voltage, the switch drive voltage, and the positive output voltage, obtain the voltage difference between the midpoint voltage and the switch drive voltage and the positive output voltage, respectively. It is understandable that the voltage difference is the difference between the midpoint voltage and the positive voltage of the switch drive voltage output terminal. It is a parameter that reflects the working state of the switch and embodies the matching degree between the switch drive signal and the actual working state.

[0055] In some examples, based on the voltage signal acquired by S1, the data processing is performed by the arithmetic unit of the control module to calculate two sets of voltage differences: the difference between the intermediate point voltage and the switch drive voltage, and the difference between the intermediate point voltage and the positive voltage of the output terminal. The acquired voltage signal is converted into a relative value signal reflecting the degree of state matching, providing a quantifiable basis for subsequent threshold comparison.

[0056] S3. Determine whether the charging switch and / or discharging switch are faulty based on the midpoint voltage and voltage difference.

[0057] Understandably, preset thresholds are voltage reference values ​​pre-set based on the electrical characteristics of the switching transistor, circuit design parameters, and fault judgment criteria. These include threshold values ​​for the voltage difference between normal and abnormal drive conditions, and voltage thresholds for switch on / off states; these are critical values ​​that distinguish between normal and fault states. Preset faults are the fault types defined in S1 that require diagnosis, including abnormal drive, stuck charging switch, stuck discharging switch, and switch sticking.

[0058] In some examples, the intermediate point voltage collected by S1 and the two voltage differences calculated by S2 are compared with corresponding preset thresholds. The duration of the comparison results, combined with the voltage signal duration, avoids transient interference and ensures reliable judgment, determining whether the charging switch and / or discharging switch meet preset fault characteristics. If the comparison results meet the fault judgment conditions, the corresponding fault type is determined. If all comparison results meet the normal state standards, the switching transistor is determined to be fault-free.

[0059] Reference Figure 3 In some embodiments, driving the charging switch and discharging switch to switch on and off includes: S101, Control the charging switch and discharging switch to close synchronously; It is understandable that the charging and discharging switches are controlled to close synchronously for jam detection, which detects faults where the switching transistors fail to switch on and off normally as instructed. Synchronous closing means that the charging and discharging switches enter the closed state simultaneously under the action of the control signal. This switching ensures that the charging and discharging switching transistors are in a unified working state, providing a stable detection environment for subsequent accurate capture of jam-related fault characteristic signals.

[0060] In some cases, when it is necessary to detect whether the charging switch or discharging switch is stuck, the control module sends a synchronous closing command to the drive circuit, driving the charging switch and discharging switch to switch to the closed state at the same time, ensuring that the two switches are in the same target operating state, laying the foundation for subsequent determination of the stuck fault by comparing voltage signals.

[0061] Determining whether the charging switch and / or discharging switch is faulty based on the intermediate point voltage and voltage difference includes: S301, determining whether the switch drive is abnormal based on whether the first voltage difference between the intermediate point voltage and the switch drive voltage is less than a first threshold. Understandably, the first threshold is a pre-set critical value based on the electrical characteristics and normal operating voltage range of the switching transistor's drive circuit. It's used to distinguish whether the drive signal is effectively applied to the switching transistor. The first threshold is the voltage required for the switching transistor to start normally. Taking a MOSFET as an example, determined by the MOSFET drive voltage and manufacturing process, a voltage greater than 9V ensures the MOSFET can turn on normally; therefore, the first threshold can be 9V. Since the MOSFET's turn-on and turn-off voltages are 1.2-2V, and its fully turn-on voltage (when its impedance is lowest) is 10V, the drive voltage output by the GDU is 12.5V. A voltage greater than 9V (considering voltage acquisition deviation) meets the normal operating requirements of the MOSFET. The first voltage difference between the midpoint voltage and the switch drive voltage reflects the degree of matching between the drive signal and the actual operating state of the switching transistor, and is a parameter for determining whether the drive is abnormal.

[0062] In some cases, based on the intermediate point voltage and switch drive voltage collected by S1, a first voltage difference between the two is calculated and compared with a first threshold. If the first voltage difference is less than the first threshold, it indicates that the drive signal has not effectively driven the switch to the expected operating state, and the switch drive is determined to be abnormal; if the first voltage difference is not less than the first threshold, it indicates that the drive signal matches the actual response of the switch, and the switch drive is determined to be normal.

[0063] S302. Determine whether the discharge switch is stuck based on whether the intermediate point voltage is less than or equal to the second threshold. Understandably, the second threshold is a preset reference value based on the normal range of the midpoint voltage when the switch is closed. The change in the midpoint voltage is directly related to the closed state of the discharge switch. The second threshold is determined by whether the midpoint voltage exceeds or is less than the second threshold when the discharge switch is normally closed. The second threshold is determined based on the battery system's operating voltage. For example, if the normal operating voltage of the battery system is 9V and the minimum operating voltage is 6V, then the second threshold value is between 6V and 9V, and can be 6V, 7V, 8V, 9V, etc., with the normal operating voltage being preferred, i.e., the second threshold is 9V.

[0064] In some cases, the intermediate point voltage collected by S1 is compared with the second threshold. If the intermediate point voltage is greater than the second threshold, it indicates that the discharge switch has been successfully closed without any jamming fault; if the intermediate point voltage is not greater than the second threshold, it indicates that the discharge switch has not closed normally as instructed, and there is a jamming fault.

[0065] S303. Determine whether the charging switch is stuck based on whether the second voltage difference between the midpoint voltage and the positive voltage at the output terminal is greater than the third threshold.

[0066] Understandably, the third threshold is a preset critical value that combines the difference between the positive voltage at the output terminal (the voltage between the charging and discharging switches on the load side) and the midpoint voltage when the charging switch is normally closed. It is generally the voltage drop at which the switching transistor is fully turned on, such as 0.3V. The second voltage difference directly reflects the conduction state of the charging switch. If the charging switch is normally closed, the second voltage difference will be within a small range; if there is any jamming, the second voltage difference will increase significantly.

[0067] In some cases, the second voltage difference between the midpoint voltage collected by S1 and the positive voltage at the output terminal is calculated and compared with a third threshold. If the second voltage difference is greater than the third threshold, it indicates that the charging switch is not effectively turned on and there is a jamming fault; if the second voltage difference is not greater than the third threshold, it indicates that the charging switch is normally turned on and there is no jamming fault.

[0068] It should be noted that there is no strict order requirement for S301, S302 and S303. They can be performed in the order of S301, S302 and S303, or in other orders, such as S302, S301 and S303. S301, S302 and S303 can also be performed simultaneously. The specific judgment order can be set according to actual needs.

[0069] Reference Figure 4 In some embodiments, determining whether the switch drive is abnormal based on whether the first voltage difference between the intermediate point voltage and the switch drive voltage is less than a first threshold includes: S3011. When the first voltage difference between the intermediate point voltage and the switch drive voltage is less than the first threshold, control the charging switch and the discharging switch to close synchronously for a first preset time. If the first voltage difference is still less than the first threshold, determine that the switch drive is abnormal. Understandably, the first preset time is a time threshold pre-set based on the response characteristics of the switching transistor and the time required for circuit stabilization. This ensures that the charging and discharging switches have sufficient time to complete their closing action and reach a stable operating state. The synchronous closing duration of the first preset time, such as 150ms-250ms (e.g., 150ms, 200ms, 250ms), prevents misjudgments of faults caused by switching transistor response delays or circuit instability, providing accurate data for subsequent voltage signal acquisition and fault diagnosis.

[0070] In some cases, when the preset fault detection item is jamming detection, the control module sends a synchronous closing command to the drive circuit, driving the charging switch and the discharging switch to enter the closed state simultaneously, and maintaining this closed state for a first preset time. After the switching transistor's operating state stabilizes, the intermediate point voltage, switch drive voltage, and output positive terminal voltage are then collected to ensure that the collected voltage signals can accurately reflect the actual operating state of the switching transistor, thus improving the accuracy of the switching transistor drive anomaly detection.

[0071] In some embodiments, refer to Figure 5 To determine whether the discharge switch is stuck, the system checks whether the voltage at the midpoint is less than or equal to the second threshold, including: S3021. When the intermediate point voltage is greater than the second threshold, control the charging switch and the discharging switch to close synchronously for a second preset time. If the intermediate point voltage is still less than or equal to the second threshold, determine that the discharging switch is stuck. Understandably, the second preset time is a time threshold pre-set based on the response characteristics of the switching transistor and the time required for circuit stabilization. It ensures that the charging and discharging switches have sufficient time to complete their closing action and reach a stable operating state. The synchronous closing duration is a second preset time, such as 150ms-250ms, which can be 150ms, 200ms, 250ms, etc., to prevent misjudgments of faults caused by switching transistor response delays or circuit instability, providing accurate data for subsequent voltage signal acquisition and fault diagnosis.

[0072] In some cases, when the preset fault detection item is jamming detection, the control module sends a synchronous closing command to the drive circuit, driving the charging switch and the discharging switch to simultaneously enter the closed state and maintain this closed state for a second preset time. After the switching transistor's operating state stabilizes, the intermediate point voltage, switch drive voltage, and output positive terminal voltage are then collected to ensure that the collected voltage signals can accurately reflect the actual operating state of the switching transistor and improve the accuracy of the discharge switch jamming fault determination.

[0073] In some embodiments, refer to Figure 6 To determine if the charging switch is stuck, the second voltage difference between the midpoint voltage and the positive output voltage is greater than a third threshold, including: S3031. When the second voltage difference between the intermediate point voltage and the positive voltage at the output terminal is greater than the third threshold, control the charging switch and the discharging switch to close synchronously for a third preset time. If the second voltage difference between the intermediate point voltage and the positive voltage at the output terminal is still greater than the third threshold, determine that the charging switch is stuck.

[0074] Understandably, the third preset time is a time threshold pre-set based on the response characteristics of the switching transistor and the time required for circuit stabilization. This ensures that the charging and discharging switches have sufficient time to complete their closing action and reach a stable operating state. The synchronous closing duration of the third preset time, such as 150ms-250ms (e.g., 150ms, 200ms, 250ms), prevents misjudgments of faults caused by switching transistor response delays or circuit instability, providing accurate data for subsequent voltage signal acquisition and fault diagnosis.

[0075] In some cases, when the preset fault detection item is jamming detection, the control module sends a synchronous closing command to the drive circuit, driving the charging switch and the discharging switch to enter the closed state simultaneously, and maintaining this closed state for a third preset time. After the switching transistor's operating state stabilizes, the intermediate point voltage, switch drive voltage, and output positive terminal voltage are then collected to ensure that the collected voltage signals can accurately reflect the actual operating state of the switching transistor, thereby improving the accuracy of charging switch jamming fault determination.

[0076] It should be noted that the first, second, and third preset times can be the same or different, and can be flexibly set according to application needs.

[0077] Reference Figure 7 and Figure 8 In some embodiments, when the first voltage difference between the intermediate point voltage and the switch drive voltage is less than a first threshold, the charging switch and the discharging switch are controlled to close synchronously for a first preset time. If the first voltage difference is still less than the first threshold, a switch drive abnormality is determined, including: S3012. When the first voltage difference between the intermediate point voltage and the switch drive voltage is less than the first threshold, control the charging switch and the discharging switch to open synchronously and then close synchronously. Repeat this N times. If the first voltage difference is still less than the first threshold, then determine that the switch drive is abnormal. N is an integer greater than 1. Understandably, repeating the synchronous disconnection and reconnection action N times, where N is an integer greater than 1 (e.g., 2, 3, 4), is to eliminate the influence of accidental factors such as instantaneous voltage interference and switching transistor response delay, thereby improving the reliability of fault diagnosis. This action is triggered by an initial abnormal signal when the first voltage difference is less than a first threshold. Through multiple loops, it verifies whether the drive abnormality is a persistent fault, avoiding misjudgments from a single detection.

[0078] In some cases, when the first voltage difference between the intermediate point voltage and the switch drive voltage is detected to be less than a first threshold, the control module first drives the charging switch and the discharging switch to open synchronously. After a preset delay to ensure that the switching transistor is completely disconnected, it then drives them to close synchronously. After the state stabilizes, the first voltage difference is detected again. This cycle of opening and closing is repeated a preset number of times. If the first voltage difference is still less than the first threshold, the switch drive is determined to be abnormal. If the first voltage difference recovers to a level not less than the first threshold during the cycle, it is determined to be a transient interference, and the drive abnormality fault is eliminated.

[0079] When the intermediate point voltage is greater than the second threshold, the charging switch and the discharging switch are controlled to close synchronously for a second preset time. If the intermediate point voltage is still less than or equal to the second threshold, the discharging switch is determined to be stuck, including: S3022. When the intermediate point voltage is greater than the second threshold, control the charging switch and the discharging switch to open synchronously and then close synchronously. Repeat this process M times. If the intermediate point voltage is still greater than the second threshold, then the discharging switch is determined to be stuck. M is an integer greater than 1.

[0080] Understandably, a voltage greater than the second threshold is a preliminary signal that the discharge switch may be stuck. Repeating the synchronous disconnection and synchronous closure action M times, where M is an integer greater than 1, such as 2, 3, 4, etc., is to verify whether the switch can respond to the control signal by triggering multiple instructions, eliminating misjudgments caused by instantaneous fluctuations in the circuit. This cyclic action can more accurately confirm whether the discharge switch cannot close normally due to sticking.

[0081] In some cases, when the acquired intermediate-point voltage exceeds the second threshold, the control module initiates a cyclic detection process. First, it controls the charging and discharging switches to open synchronously and maintain this for a preset delay. Then, it controls them to close synchronously and stabilize for a period of time before re-acquiring the intermediate-point voltage. If the intermediate-point voltage remains above the second threshold after this cyclic action is repeated a preset number of times, a jamming fault in the discharging switch is confirmed. If the intermediate-point voltage recovers to a level not exceeding the second threshold during the cycle, it indicates that the switching transistor can respond normally to commands, thus eliminating the jamming fault.

[0082] Reference Figure 9 In some embodiments, when the first voltage difference is less than a first threshold, the charging switch and the discharging switch are controlled to open synchronously and then close synchronously. After repeating this process N times, if the first voltage difference is still less than the first threshold, then the switching transistor drive is determined to be abnormal, where N is an integer greater than 1, including: S3013. When the first voltage difference is less than the first threshold, control the charging switch and the discharging switch to open synchronously and continue for a fourth preset time, then close synchronously and continue for a fifth preset time. If the first voltage difference is still less than the first threshold after repeating this process multiple times, then determine that the switching transistor is driving abnormally.

[0083] Understandably, the fourth preset time is a time threshold preset based on the switching response characteristics of the switching transistor and the time required for the residual voltage in the circuit to release, such as 20ms-40ms, which can be 20ms, 30ms, 40ms, etc., to ensure that the charging switch and discharging switch can be completely disconnected and the circuit state is stable. Maintaining this duration after synchronous disconnection can prevent incomplete switching or residual voltage in the circuit from interfering with subsequent closing actions and voltage detection.

[0084] Understandably, the fifth preset time is a time threshold preset based on the closing response speed of the switching transistor and the time required for the circuit to reach a stable operating state, such as 20ms-40ms. It can be 20ms, 30ms, 40ms, etc., to ensure that the charging switch and discharging switch can be fully closed and enter a stable operating state. Maintaining this duration after synchronous closing ensures that the subsequently acquired voltage signal accurately reflects the actual operating state of the switching transistor, avoiding misjudgments of faults caused by unstable switching.

[0085] In some cases, when the first voltage difference between the intermediate point voltage and the switch drive voltage is less than the first threshold, the control module first sends a synchronous disconnect command to drive the charging switch and the discharging switch to disconnect simultaneously, and maintains this disconnected state for a fourth preset time to ensure that the switching transistor is completely disconnected from the conduction state, the residual energy of the circuit is completely released, and the accuracy of subsequent voltage acquisition and fault determination is guaranteed.

[0086] In some cases, after the synchronous disconnection of S3013 and the stabilization of the fourth preset time, the control module sends a synchronous closing command to drive the charging switch and the discharging switch to close simultaneously, and maintains the closed state for the fifth preset time. After the switching transistor is stable and the circuit voltage distribution is balanced, the relevant voltage signals are collected and compared to provide accurate data support for fault diagnosis.

[0087] In some embodiments, refer to Figure 10 When the intermediate point voltage is greater than the second threshold, the charging switch and the discharging switch are simultaneously opened and then simultaneously closed. This process is repeated M times. If the intermediate point voltage is still greater than the second threshold, then the discharging switch is determined to be stuck. M is an integer greater than 1, including: S3023. When the intermediate point voltage is greater than the second threshold, control the charging switch and the discharging switch to open synchronously and continue for a sixth preset time, then close synchronously and continue for a seventh preset time. If the intermediate point voltage is still greater than the second threshold after repeating this process multiple times, it is determined that the discharging switch is stuck.

[0088] Understandably, the sixth preset time is a time threshold preset based on the switching response characteristics of the switching transistor and the time required for the residual voltage in the circuit to release, such as 20ms-40ms, which can be 20ms, 30ms, 40ms, etc., to ensure that the charging switch and discharging switch can be completely disconnected and the circuit state is stable. Maintaining this duration after synchronous disconnection can prevent incomplete switching or residual voltage in the circuit from interfering with subsequent closing actions and voltage detection.

[0089] Understandably, the seventh preset time is a time threshold preset based on the closing response speed of the switching transistor and the time required for the circuit to reach a stable operating state, such as 20ms-40ms. It can be 20ms, 30ms, 40ms, etc., to ensure that the charging switch and discharging switch can be fully closed and enter a stable operating state. Maintaining this duration after synchronous closing ensures that the subsequently acquired voltage signal accurately reflects the actual operating state of the switching transistor, avoiding misjudgments of faults caused by unstable switching.

[0090] In some cases, when the midpoint voltage is detected to be greater than the second threshold, the control module first sends a synchronous disconnect command to drive the charging switch and the discharging switch to disconnect simultaneously, and maintains the disconnected state for a sixth preset time to ensure that the switching transistor is completely disconnected from the conducting state, the residual energy of the circuit is fully released, and the accuracy of subsequent voltage acquisition and fault determination is guaranteed.

[0091] In some cases, after the synchronous disconnection of S3023 and the stabilization of the sixth preset time, the control module sends a synchronous closing command to drive the charging switch and the discharging switch to close simultaneously, and maintains the closed state for the seventh preset time. After the switching transistor is stable and the circuit voltage distribution is balanced, the relevant voltage signals are collected and compared to provide accurate data support for fault diagnosis.

[0092] It should be noted that the fourth, fifth, sixth, and seventh preset times can be the same or different, and can be flexibly set according to application needs.

[0093] Reference Figure 11 In some embodiments, controlling the charging switch and discharging switch to close synchronously includes: S100, the battery system is powered on and woken up, performs a self-test and finds no faults, and controls the switching circuit to be in a discharging state, and initializes the number of synchronous disconnections and synchronous closures.

[0094] Understandably, system power-on wake-up refers to the low-voltage lithium battery management system entering working mode from sleep mode after power is connected, providing a basic operating environment for fault detection. Self-test without faults means that after system startup, it first performs preliminary checks on its own circuits, sampling units, etc., to confirm the absence of operational faults before conducting jamming detection, preventing operational faults from interfering with the jamming judgment results. Discharge state is the target operating scenario for jamming detection, ensuring that the detection closely matches actual application conditions. Initializing the synchronous disconnection and synchronous closing counts means resetting the cycle count parameters used for repeated fault verification to their initial values, preparing data for possible subsequent multiple on / off cycles.

[0095] In some cases, when the low-voltage lithium battery management system is powered on and woken up, it first completes a self-test of its core components. When it confirms that there is no basic fault and the system is in a discharging state, the control module initializes the counting parameters for synchronous disconnection and synchronous closure. Then, it sends a command to the drive circuit to control the charging switch and discharging switch to switch to the closed state synchronously, thus formally starting the jamming detection process and laying the foundation for subsequent determination of jamming faults by comparing voltage signals.

[0096] Reference Figure 12 In some embodiments, driving the charging switch and discharging switch to switch on and off includes: S102, Control the charging switch and discharging switch to disconnect synchronously; Understandably, adhesion detection is used to detect fault types where the switching transistor fails to disconnect normally as instructed and remains in a conducting state. Synchronous disconnection refers to the charging switch and discharging switch simultaneously entering the disconnected state under the action of a control signal. This switching process ensures that both switching transistors are in a unified disconnection target state, providing a stable detection basis for capturing adhesion-related fault characteristic signals.

[0097] In some cases, when it is necessary to detect whether the charging switch or discharging switch has a sticking fault, the control module sends a synchronous disconnect command to the drive circuit, driving the charging switch and discharging switch to switch to the disconnect state at the same time, ensuring that the two switching transistors are in the same target operating state, creating conditions for subsequent determination of sticking faults by comparing voltage signals.

[0098] Determining whether the charging switch and / or discharging switch is faulty based on the midpoint voltage and voltage difference includes: S304, determining whether the switch transistor drive is abnormal based on whether the midpoint voltage is greater than the fourth threshold. Understandably, the fourth threshold is a pre-set critical value based on the normal range of the midpoint voltage when the switch is off. Changes in the midpoint voltage directly relate to the effectiveness of the switch drive signal and are a core parameter for initially determining whether the drive is abnormal. The fourth threshold is the minimum operating voltage of the switch circuit in the battery system, such as 6V.

[0099] In some cases, after the charging and discharging switches are simultaneously disconnected and the circuit stabilizes, the intermediate point voltage is collected and compared with a fourth threshold. If the intermediate point voltage is greater than the fourth threshold, it indicates that the drive signal is not effectively applied to the switching transistor, and the switching transistor drive is preliminarily determined to be abnormal; if the intermediate point voltage is not greater than the fourth threshold, it indicates that the drive signal matches the disconnected state of the switching transistor, and the drive state is normal.

[0100] S305. Determine whether the switching transistor is driving abnormally or the charging switch and discharging switch are stuck together based on whether the first voltage difference between the intermediate point voltage and the switching drive voltage is greater than the first threshold.

[0101] Understandably, the first threshold is a preset critical value that combines the voltage difference range corresponding to switching transistor drive abnormality and sticking fault. The first voltage difference between the midpoint voltage and the switching drive voltage can distinguish between the two different fault types of drive abnormality and sticking, and is a key parameter for accurately determining the root cause of the fault. The first threshold can be the same as the first threshold value in S301.

[0102] In some cases, after calculating the first voltage difference between the intermediate point voltage and the switch drive voltage, it is compared with a first threshold. Based on the preliminary judgment result of S304, if the first voltage difference is greater than the first threshold and S304 determines that the drive is normal, it indicates that the switch transistor did not respond to the disconnect command, confirming that the charging switch and the discharging switch are stuck together; if the first voltage difference is greater than the first threshold and S304 determines that the drive is abnormal, it is determined that the abnormal state is caused by an abnormal switch transistor drive; if the first voltage difference is not greater than the first threshold, it indicates that the switch transistor is in normal state and there is no sticking fault.

[0103] Reference Figure 13 In some embodiments, determining whether the switch drive is abnormal based on whether the intermediate point voltage is greater than a fourth threshold includes: S3041, when the intermediate point voltage is greater than the fourth threshold, controlling the charging switch and the discharging switch to be synchronously disconnected for an eighth preset time; if the intermediate point voltage is still greater than the fourth threshold, determining whether the switch drive is abnormal or the charging switch and the discharging switch are stuck based on whether the first voltage difference between the intermediate point voltage and the switch drive voltage is greater than a first threshold; if the intermediate point voltage is less than or equal to the fourth threshold, determining whether the switch drive is abnormal based on whether the intermediate point voltage is greater than the fourth threshold.

[0104] Understandably, the eighth preset time is a time threshold preset based on the stability requirements of the switch in the off state and the duration of residual energy release in the circuit, such as 0.5s-1.5s. It can be 0.5s, 1s, 1.5s, etc., ensuring that the charging and discharging switches remain off and allow the circuit to stabilize even under abnormal drive signal conditions. This time setting prevents misjudgments caused by circuit instability and provides reliable conditions for further confirmation of whether the drive is abnormal.

[0105] In some cases, when the voltage difference between the intermediate point voltage and the switch drive voltage is detected to be greater than the fourth threshold, it indicates that the current drive signal may not be effectively applied to the switch. The control module will control the charging switch and the discharging switch to continue to remain in a synchronously disconnected state, and maintain this state for more than the eighth preset time. This ensures that the switch is completely disconnected and the residual voltage in the circuit is completely released before subsequent voltage detection or fault determination is performed, thereby improving the accuracy of drive state determination.

[0106] Understandably, the eighth preset time is a time threshold preset based on the switching transistor's disconnection response characteristics and the residual voltage release time of the circuit, such as 0.5s-1.5s, which can be 0.5s, 1s, 1.5s, etc., to ensure that the charging switch and discharging switch can maintain a stable disconnected state and eliminate interference caused by instantaneous voltage fluctuations or incomplete switch disconnection. The first voltage difference is the difference between the midpoint voltage and the switch drive voltage, which is the core judgment parameter for distinguishing between two types of faults: abnormal switching transistor drive and switch sticking.

[0107] In some cases, when the intermediate point voltage is detected to be greater than the fourth threshold, the control module controls the charging switch and discharging switch to remain synchronously disconnected for a period of time up to the eighth preset time. After the circuit state is completely stable, the intermediate point voltage is collected again. If the intermediate point voltage collected again is still greater than the fourth threshold, the first voltage difference between the intermediate point voltage and the switch drive voltage is calculated and compared with the first threshold to determine whether the switch drive is abnormal or the charging switch and discharging switch are stuck together. If the intermediate point voltage collected again is less than or equal to the fourth threshold, the intermediate point voltage is compared with the fourth threshold again to determine whether the switch drive is abnormal.

[0108] Reference Figure 14 In some embodiments, controlling the charging switch and discharging switch to disconnect synchronously includes: S1021. When the system is in normal operation, control the charging switch and the discharging switch to disconnect synchronously; Understandably, normal operation refers to the low-voltage lithium battery management system operating stably according to a preset program, without fundamental faults, and meeting the requirements for adhesion detection. In this state, controlling the charging and discharging switches to disconnect synchronously is to verify whether the switching transistors can respond normally to the disconnection command during actual system operation.

[0109] In some cases, when the system is in a normal charging and discharging state without other fault alarms, the control module sends a synchronous disconnect command to the drive circuit according to the adhesion detection requirements, driving the charging switch and the discharging switch to switch to the disconnect state at the same time, providing a detection environment for subsequent determination of adhesion faults by comparing voltage signals.

[0110] S1022. When the system is in a sleep-wake state, confirm that the charging switch and the discharging switch are disconnected synchronously.

[0111] It's understandable that the sleep / wake-up state refers to the transitional state where the system recovers from a low-power sleep mode to the operating mode; at this time, the system has not yet entered the formal operation process. Confirming that the charging and discharging switches are disconnected during this stage allows for direct troubleshooting of whether the switches are stuck together, preventing faulty switches from entering the normal operation phase and causing circuit abnormalities.

[0112] In some cases, after the system is woken up from sleep mode, the control module does not immediately send on / off commands, but directly collects voltage signals related to the switch state through the sampling unit to confirm whether the charging switch and discharging switch are in the off state.

[0113] Reference Figure 15In some embodiments, driving the charging switch and the discharging switch to switch on and off, and obtaining the midpoint voltage between the charging switch and the discharging switch, the switch driving voltage and the positive voltage of the output terminal, includes: S103, obtaining the midpoint voltage of each pair of charging switches and charging switches in the plurality of pairs of charging switches and charging switches respectively.

[0114] Understandably, when a system has multiple pairs of charging and discharging switches, these switches are connected in parallel. By shunting the current through multiple pairs of switches, the on / off state of larger currents can be controlled. Each pair of charging and discharging switches corresponds to an independent intermediate point, and the voltage at each intermediate point reflects the operating status of the corresponding switch pair. By acquiring the intermediate point voltage of each pair of switches, the system can detect each group of switches, preventing faults from being missed due to single-point detection and ensuring that the operating status of all switches can be effectively monitored.

[0115] In some cases, according to the requirements of the preset fault detection items, after the control module drives all charging switches and discharging switches to perform on and off actions synchronously, it collects the voltage at the midpoint between each pair of charging switches and discharging switches through the sampling unit corresponding to each midpoint. At the same time, it collects the switch drive voltage and the positive voltage of the output terminal shared by all switches, providing independent and comprehensive voltage data support for subsequent determination of the fault status of each pair of switches.

[0116] According to the second aspect of this disclosure, referring to Figure 16 A switching transistor fault detection device is provided, comprising a drive module 401, a parameter acquisition module 402, a processing module 403, and a determination module 404. The drive module 401 is used to drive a charging switch and a discharging switch to switch on and off. The parameter acquisition module 402 is used to acquire the midpoint voltage, the switch drive voltage, and the positive output voltage between the charging switch and the discharging switch. The processing module 403 is used to obtain the voltage difference between the midpoint voltage and the switch drive voltage and the positive output voltage, respectively, based on the midpoint voltage, the switch drive voltage, and the positive output voltage. The determination module 404 is used to compare the midpoint voltage and the voltage difference with a preset threshold to determine whether the charging switch and / or the discharging switch has malfunctioned.

[0117] It is understood that the drive module 401 may include a drive circuit integrated in the main control chip, a functional module for outputting control commands to adjust the on / off states of the charging switch and the discharging switch, and can output corresponding on / off control signals according to different preset fault detection items. The parameter acquisition module 402 may include a memory, a functional module for acquiring various voltage signals in the circuit, and can accurately acquire the midpoint voltage between the charging switch and the discharging switch, the switching drive voltage output by the drive circuit, and the positive voltage of the output terminal of a specific endpoint of the switching transistor. The processing module 403 may include the main control chip, processor, etc., a functional module for processing the acquired voltage signals, and can perform voltage difference calculation operations. The determination module 404 may include a comparison circuit integrated in the main control chip, a functional module for comparing and analyzing the processed voltage parameters with preset thresholds, and can determine the fault type of the switching transistor based on the comparison results.

[0118] When a preset fault detection item is started, the drive module 401 outputs control commands according to the detection requirements of the item, driving the charging switch and discharging switch to switch to the target on / off state. After the charging switch and discharging switch reach the target on / off state, the parameter acquisition module 402 starts to collect the corresponding intermediate point voltage, switch drive voltage, and output terminal positive voltage. The processing module 403 receives the voltage signals collected by the parameter acquisition module 402 and calculates the voltage difference between the intermediate point voltage and the switch drive voltage and the output terminal positive voltage, respectively. The determination module 404 receives the voltage difference output by the processing module 403 and the intermediate point voltage collected by the parameter acquisition module 402, compares these parameters with the corresponding preset thresholds, and determines the state of the switch based on the comparison results.

[0119] In some embodiments, the collaborative operation of the drive module 401, parameter acquisition module 402, processing module 403, and determination module 404 enables automated detection of charging and discharging switch faults. The modules have clearly defined roles and seamless integration, enabling rapid and accurate identification of fault types such as abnormal switching transistor drive, jamming, and sticking, thereby improving the safety and reliability of the low-voltage lithium battery system.

[0120] According to a third aspect of this disclosure, a storage medium is provided that stores a computer program thereon, which, when run on a computer, causes the computer to execute the above-described switching transistor fault detection method.

[0121] This application also proposes a storage medium storing a computer program thereon. When the computer program is run on a computer, it causes the computer to execute the above-described switching transistor fault detection method. The specific structure of the switching transistor fault detection method is as described in the above embodiments. Since this storage medium adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be elaborated here.

[0122] According to a fourth aspect of this disclosure, an electronic device is provided, including a processor and a memory. The memory contains a computer program, and the processor executes the aforementioned switching transistor fault detection method by calling the computer program. The specific structure of this switching transistor fault detection method is as described in the above embodiments. Since this electronic device adopts all the technical solutions of all the above embodiments, it possesses at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be elaborated upon here.

[0123] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0124] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0125] The embodiments, implementation methods, and related technical features of this application can be combined and substituted for each other without conflict.

[0126] The above are merely preferred embodiments of this application and are not intended to limit this application in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of this application without departing from the scope of the technical solution of this application shall still fall within the scope of the technical solution of this application.

Claims

1. A method for detecting faults in a switching transistor, characterized in that, A switching circuit applied to a battery system, the switching circuit being connected between the positive terminal of the battery pack and the positive terminal of the output terminal, the switching circuit including a charging switch and a discharging switch, and a fault detection method for the switching transistor including: Drive the charging switch and the discharging switch to switch on and off, and obtain the midpoint voltage between the charging switch and the discharging switch, the switching drive voltage of the charging switch and the discharging switch and the positive voltage of the output terminal when the switching circuit is in different states; Based on the intermediate point voltage, the switch drive voltage, and the positive output voltage, the voltage differences between the intermediate point voltage and the switch drive voltage and the positive output voltage are obtained respectively. Based on the intermediate point voltage and the voltage difference, determine whether the charging switch and / or the discharging switch is faulty.

2. The switching transistor fault detection method according to claim 1, characterized in that, Driving the charging switch and the discharging switch to switch on and off includes: Control the charging switch and the discharging switch to close synchronously; Determining whether the charging switch and / or the discharging switch is faulty based on the intermediate point voltage and the voltage difference includes: Based on whether the first voltage difference between the intermediate point voltage and the switch drive voltage is less than a first threshold, determine whether the switch drive is abnormal; and / or, Whether the discharge switch is stuck is determined based on whether the intermediate point voltage is less than or equal to the second threshold; and / or, Whether the charging switch is stuck is determined by whether the second voltage difference between the intermediate point voltage and the positive voltage of the output terminal is greater than a third threshold.

3. The switching transistor fault detection method according to claim 2, characterized in that, Determining whether the switch drive is abnormal based on whether the first voltage difference between the intermediate point voltage and the switch drive voltage is less than the first threshold includes: When the first voltage difference between the intermediate point voltage and the switch drive voltage is less than the first threshold, the charging switch and the discharging switch are controlled to close synchronously for a first preset time. If the first voltage difference is still less than the first threshold, a switch drive malfunction is determined; and / or, Determining whether the discharge switch is stuck based on whether the intermediate point voltage is less than or equal to the second threshold includes: When the intermediate point voltage is greater than the second threshold, the charging switch and the discharging switch are controlled to close synchronously for a second preset time. If the intermediate point voltage is still less than or equal to the second threshold, the discharging switch is determined to be stuck; and / or, Determining whether the charging switch is stuck based on whether the second voltage difference between the intermediate point voltage and the positive voltage at the output terminal is greater than the third threshold includes: When the second voltage difference between the intermediate point voltage and the positive voltage at the output terminal is greater than the third threshold, the charging switch and the discharging switch are controlled to close synchronously for a third preset time. If the second voltage difference between the intermediate point voltage and the positive voltage at the output terminal is still greater than the third threshold, the charging switch is determined to be stuck.

4. The switching transistor fault detection method according to claim 3, characterized in that, When the first voltage difference between the intermediate point voltage and the switch drive voltage is less than the first threshold, the charging switch and the discharging switch are controlled to close synchronously for a first preset time. If the first voltage difference is still less than the first threshold, a switch drive abnormality is determined, including: When the first voltage difference is less than the first threshold, the charging switch and the discharging switch are controlled to open synchronously and then close synchronously. This process is repeated N times. If the first voltage difference is still less than the first threshold, then the switching transistor is determined to be abnormal, where N is an integer greater than 1; and / or, When the intermediate point voltage is greater than the second threshold, the charging switch and the discharging switch are controlled to close synchronously for the second preset time. If the intermediate point voltage is still less than or equal to the second threshold, it is determined that the discharging switch is stuck, including: When the intermediate point voltage is greater than the second threshold, the charging switch and the discharging switch are controlled to open synchronously and then close synchronously. After repeating this process M times, if the intermediate point voltage is still greater than the second threshold, it is determined that the discharging switch is stuck, where M is an integer greater than 1.

5. The switching transistor fault detection method according to claim 4, characterized in that, When the first voltage difference is less than the first threshold, the charging switch and the discharging switch are controlled to open synchronously and then close synchronously. This process is repeated N times. If the first voltage difference is still less than the first threshold, then the switching transistor drive is determined to be abnormal, where N is an integer greater than 1. This includes: When the first voltage difference is less than the first threshold, the charging switch and the discharging switch are controlled to open synchronously for a fourth preset time, then close synchronously for a fifth preset time. After repeating this process multiple times, if the first voltage difference is still less than the first threshold, then the switch tube is determined to be driving abnormally. And / or, When the intermediate point voltage is greater than the second threshold, the charging switch and the discharging switch are controlled to open synchronously and then close synchronously. This process is repeated M times. If the intermediate point voltage is still greater than the second threshold, then the discharging switch is determined to be stuck. M is an integer greater than 1, including: When the intermediate point voltage is greater than the second threshold, the charging switch and the discharging switch are controlled to open synchronously for a sixth preset time, then close synchronously for a seventh preset time. If the intermediate point voltage is still greater than the second threshold after repeating this process multiple times, it is determined that the discharging switch is stuck.

6. The switching transistor fault detection method according to claim 4, characterized in that, Before controlling the charging switch and the discharging switch to close synchronously, the method includes: The battery system is powered on and woken up, performs a self-test and finds no faults, and controls the switching circuit to be in a discharging state, initializing the number of synchronous disconnections and synchronous closures.

7. The switching transistor fault detection method according to any one of claims 1-6, characterized in that, The process of driving the charging switch and discharging switch to switch on and off includes: The charging switch and the discharging switch are controlled to disconnect synchronously. Determining whether the charging switch and / or the discharging switch is faulty based on the intermediate point voltage and the voltage difference includes: Whether the intermediate point voltage is greater than the fourth threshold is used to determine whether the switch drive is abnormal; Based on whether the first voltage difference between the intermediate point voltage and the switch drive voltage is greater than a first threshold, it is determined that the switch drive is abnormal or the charging switch and the discharging switch are stuck together.

8. The switching transistor fault detection method according to claim 7, characterized in that, Determining whether the switch driver is malfunctioning based on whether the intermediate point voltage is greater than the fourth threshold includes: When the intermediate point voltage is greater than the fourth threshold, the charging switch and the discharging switch are controlled to disconnect synchronously for an eighth preset time. If the intermediate point voltage is still greater than the fourth threshold, determine whether the switch drive is abnormal or the charging switch and the discharging switch are stuck together based on whether the first voltage difference between the intermediate point voltage and the switch drive voltage is greater than the first threshold. If the intermediate point voltage is less than or equal to the fourth threshold, the system continues to determine whether the switching transistor drive is abnormal based on whether the intermediate point voltage is greater than the fourth threshold.

9. The switching transistor fault detection method according to claim 7, characterized in that, Controlling the charging switch and the discharging switch to disconnect synchronously includes: When the system is in normal operating condition, the charging switch and the discharging switch are simultaneously disconnected; or, When the system is in a sleep / wake-up state, confirm that the charging switch and the discharging switch are simultaneously disconnected.

10. A switching transistor fault detection device, characterized in that, include: The drive module (401) drives the charging switch and the discharging switch to switch on and off. The parameter acquisition module (402) is used to acquire the midpoint voltage between the charging switch and the discharging switch, the switch driving voltage, and the positive voltage of the output terminal; Processing module (403) is used to obtain the voltage difference between the intermediate point voltage and the switch driving voltage and the positive output voltage, respectively, based on the intermediate point voltage, the switch driving voltage and the positive output voltage; The determination module (404) is used to compare the intermediate point voltage and the voltage difference with a preset threshold to determine whether the charging switch and / or the discharging switch has the fault.

11. A storage medium having a computer program stored thereon, characterized in that, When the computer program is run on a computer, it causes the computer to perform the switching transistor fault detection method as described in any one of claims 1 to 9.

12. An electronic device comprising a processor and a memory, wherein the memory has a computer program, characterized in that, The processor executes the switching transistor fault detection method as described in any one of claims 1 to 9 by invoking the computer program.

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