A detection system and vehicle

Abstract

This application provides a detection system and vehicle, relating to the field of voltage detection technology. The system includes first and second sampling circuits, first and second switching circuits, and a controller. The input terminals of the first and second sampling circuits are connected to a high-voltage bus, and the first and second sampling circuits output first and second sampling signals, respectively. The first terminals of the first and second switching circuits are connected to the output terminals of the first and second sampling circuits, respectively, and the second terminals of the first and second switching circuits are connected to a reference voltage. The controller receives the first and second sampling signals and controls the conduction states of the first and second switching circuits based on these signals. This system can accurately identify whether an anomaly is due to a high-voltage power supply fault or a sampling circuit fault by controlling the conduction states of the first and second switching circuits, reducing the false alarm rate, indicating system availability, and ensuring the reliability of the detection system.

Description

Technical Field

[0001] This application relates to the field of voltage detection technology, and more specifically, to a detection system and vehicle. Background Technology

[0002] The energy source for electric vehicles is a high-voltage battery, which transmits direct current (DC) to various electrical components of the vehicle (such as the drive motor) via a high-voltage direct current bus (HV). To ensure power supply reliability, the voltage of the high-voltage bus needs to be monitored.

[0003] Currently, voltage detection systems are typically installed to monitor the voltage of high-voltage buses. However, when electronic components in the voltage detection system fail, the entire system can be damaged. Related technologies cannot accurately distinguish between voltage anomalies in the high-voltage bus and those in the voltage detection system, potentially leading to detection errors. For example, if the high-voltage bus is normal but the voltage detection system is malfunctioning, the detected voltage value may be false (too high or too low), potentially triggering unnecessary protective actions (such as power outages, alarms, shutdowns, etc.), affecting the normal operation of the entire vehicle. Utility Model Content

[0004] This application provides a detection system and vehicle, which aims to solve the problem in related technologies that it is impossible to accurately identify whether the voltage abnormality is due to the high-voltage bus or the voltage detection system, which may lead to detection errors, such as false voltage values, triggering unnecessary protection actions, and affecting the normal use of the vehicle.

[0005] In a first aspect, a detection system is provided, comprising a first sampling circuit, a second sampling circuit, a first switching circuit, a second switching circuit, and a controller; the input terminal of the first sampling circuit is connected to a high-voltage bus, and the first sampling circuit is used to output a first sampling signal; the input terminal of the second sampling circuit is connected to the high-voltage bus, and the second sampling circuit is used to output a second sampling signal; the first terminal of the first switching circuit is connected to the output terminal of the first sampling circuit, and the second terminal of the first switching circuit is connected to a reference voltage; the first terminal of the second switching circuit is connected to the output terminal of the second sampling circuit, and the second terminal of the second switching circuit is connected to a reference voltage; the controller is connected to the third terminal of the first switching circuit, the third terminal of the second switching circuit, the controlled terminal of the first switching circuit, and the controlled terminal of the second switching circuit, and the controller receives the first sampling signal and the second sampling signal, and controls the conduction state of the first switching circuit and the second switching circuit based on the first sampling signal and the second sampling signal.

[0006] In the above technical solution, when the controller determines that there is no abnormality based on the first and second sampling signals, the first and second switching circuits are in the first conducting state. At this time, the controller performs real-time detection of the voltage of the high-voltage bus based on the first and second sampling signals to achieve high-voltage bus detection. The detection system then performs the high-voltage bus voltage detection function. When the controller determines that there is an abnormality based on the first and second sampling signals, the controller controls the first and second switching circuits to be in the second conducting state. The controller receives the first and second detection signals generated based on the reference voltage. The controller can then determine whether there is a fault in the sampling circuit or branch based on the first and second detection signals. At this time, the detection system performs the fault location function. If the detection signals determine that there is no abnormality in the sampling circuit and branch, it indicates that there is an abnormality in the high-voltage bus. In this case, the system triggers protection actions (such as power failure, alarm, shutdown, etc.) to prevent the high-voltage bus abnormality from affecting the normal use of the vehicle. If the detection signal determines that one of the sampling circuits or branches is abnormal, the controller can control the other sampling circuit, which is not abnormal, to enter the first conducting state to continue monitoring the high-voltage bus and determine whether there is an abnormality in the high-voltage bus. This ensures the continuity of the high-voltage bus detection and avoids detection interruption. If the detection signal determines that both sampling circuits or branches are abnormal, the detection system cannot continue to detect the high-voltage bus and must report the issue for repair of the sampling circuits or branches. Thus, by controlling the conducting states of the first and second switching circuits, this application can detect the high-voltage bus and accurately identify whether the abnormality is a high-voltage bus fault or a sampling circuit fault. This avoids false voltage alarms caused by sampling circuit faults, which could trigger unnecessary protection actions (such as power outages or alarms) and affect the normal operation of the vehicle. This improves system availability, reduces the false alarm rate, and ensures the detection reliability of the system and the reliability of the vehicle.

[0007] In conjunction with the first aspect, in some possible implementations, the first switching circuit includes a voltage source and a first switching module; the voltage source is connected to the second terminal of the second switching circuit and is used to output a reference voltage; the first terminal of the first switching module serves as the first terminal of the first switching circuit and is connected to the output terminal of the first sampling circuit; the second terminal of the first switching module serves as the second terminal of the first switching circuit and is connected to the voltage source; the third terminal of the first switching module serves as the third terminal of the first switching circuit and is connected to the controller; and the controlled terminal of the first switching module serves as the controlled terminal of the first switching circuit and is connected to the controller.

[0008] In the above technical solution, the conduction state of the first switching circuit can be switched by changing the conduction state of the first switching module, providing high switching flexibility. Furthermore, a voltage source is provided to offer a stable reference voltage to the detection system, thereby ensuring the reliability of subsequent fault detection and location of the sampling circuit based on this reference voltage.

[0009] In combination with the first aspect and the above implementation methods, in some possible implementation methods, the first switch module includes a first relay, the first relay includes a first coil and a first single-pole double-throw switch; one end of the first coil is grounded, and the other end of the first coil serves as the controlled end of the first switch module and is connected to the controller; the common end of the first single-pole double-throw switch serves as the third end of the first switch module and is connected to the controller; the first switching end of the first single-pole double-throw switch serves as the first end of the first switch module and is connected to the output end of the first sampling circuit; and the second switching end of the first single-pole double-throw switch serves as the second end of the first switch module and is connected to the voltage source.

[0010] In the above technical solution, the overall conduction state of the first switching circuit can be switched by changing the energized state of the first coil, providing high switching flexibility. Secondly, the first coil and the first single-pole double-throw switch in the first relay are physically isolated and have no direct electrical connection, effectively preventing noise interference and improving the anti-interference capability of the first switching circuit, thereby enhancing the overall safety and reliability of the system.

[0011] In combination with the first aspect and the above implementation methods, in some possible implementation methods, the second switching circuit includes a second switching module, the first end of the second switching module serves as the first end of the second switching circuit and is connected to the output end of the second sampling circuit, the second end of the second switching module serves as the second end of the second switching circuit and is connected to the voltage source, the third end of the second switching module serves as the third end of the second switching circuit and is connected to the controller, and the controlled end of the second switching module serves as the controlled end of the second switching circuit and is connected to the controller.

[0012] In the above technical solution, the conduction state of the second switching circuit can be switched by changing the conduction state of the second switching module, providing high switching flexibility. Furthermore, since the second switching module and the first switching module are connected to the same voltage source, there is no need to set a specific voltage source for each switching module, saving manufacturing costs.

[0013] In combination with the first aspect and the above implementation methods, in some possible implementation methods, the second switch module includes a second relay, the second relay includes a second coil and a second single-pole double-throw switch; one end of the second coil is grounded, and the other end of the second coil serves as the controlled end of the second switch module and is connected to the controller; the common end of the second single-pole double-throw switch serves as the third end of the second switch module and is connected to the controller; the first switching end of the second single-pole double-throw switch serves as the first end of the second switch module and is connected to the output end of the second sampling circuit; the second switching end of the second single-pole double-throw switch serves as the second end of the second switch module and is connected to the voltage source.

[0014] In the above technical solution, the overall conduction state of the second switching circuit can be switched by changing the energization state of the second coil, providing high switching flexibility. Secondly, the second coil and the second single-pole double-throw switch in the second relay are physically isolated and have no direct electrical connection, effectively preventing noise interference and improving the anti-interference capability of the second switching circuit, thereby enhancing the overall safety and reliability of the system.

[0015] In combination with the first aspect and the above implementation, in some possible implementations, the controller is used to generate an error signal based on the first sampling signal and the second sampling signal, and when the error signal is greater than or equal to the error threshold, control the second terminal of the first switching circuit to be connected to the third terminal of the first switching circuit, and control the second terminal of the second switching circuit to be connected to the third terminal of the second switching circuit.

[0016] In the above technical solution, the controller calculates an error signal based on the actual voltage value. When the error signal is greater than or equal to the error threshold, it indicates that an anomaly exists in the detection system. The controller controls the first and second switching circuits to a second conducting state, enabling the controller to locate the specific fault point. Thus, this application can determine the presence of an anomaly through the error signal, providing reliable support for subsequent fault location.

[0017] In conjunction with the first aspect and the above implementation, in some possible implementations, the controller is further configured to generate a first voltage value based on the first sampling signal and a second voltage value based on the second sampling signal, and select one of the first sampling circuit and the second sampling circuit as the main sampling circuit and the other as the sub-sampling circuit based on the first voltage value, the second voltage value and the reference voltage.

[0018] In the above technical solution, the controller can determine the "true" sampling circuit and the "false" sampling circuit based on the first voltage value, the second voltage value, and the reference voltage. Based on the detection results, it selects the "true" sampling circuit as the main sampling circuit and the "false" sampling circuit as the secondary sampling circuit. This avoids the possibility of back-and-forth switching between the main and secondary sampling circuits, which could lead to frequent fault protection strategies and false alarms, thus improving detection reliability. Secondly, this application can switch to the correct sampling circuit for voltage sampling, achieving the purpose of non-stop detection.

[0019] In conjunction with the first aspect and the above implementation methods, in some possible implementation methods, the detection system further includes a first filter circuit and a second filter circuit; the first filter circuit is connected in series between the third terminal of the first switching circuit and the controller; the second filter circuit is connected in series between the third terminal of the second switching circuit and the controller.

[0020] In the above technical solution, the first and second filtering circuits can filter the signals output by the first and second switching circuits again to further improve the integrity and accuracy of the first and second sampling signals output to the controller, and improve the reliability of the controller's detection based on the first and second sampling signals.

[0021] In combination with the first aspect and the above implementation methods, in some possible implementation methods, the first sampling circuit includes a first sampling module, a first filter, and a first isolation operational amplifier; the first terminal of the first sampling module is connected to the positive terminal of the high-voltage bus as the input terminal of the first sampling circuit; the first terminal of the first filter is connected to the second terminal of the first sampling module, and the second terminal of the first filter is connected to the negative terminal of the high-voltage bus; the non-inverting input terminal of the first isolation operational amplifier is connected to the first terminal of the first filter, the inverting input terminal of the first isolation operational amplifier is connected to the second terminal of the first filter, and the output terminal of the first isolation operational amplifier is connected to the first terminal of the first sampling circuit as the output terminal of the first sampling circuit.

[0022] In the above technical solution, the first sampling module samples the voltage of the high-voltage bus and outputs it to the first filter. The first filter filters the signal acquired by the first sampling module to remove PWM noise. The signal with PWM noise removed is output to the first isolation operational amplifier. The first isolation operational amplifier can achieve electrical isolation between the input and output terminals, and simultaneously achieve high-voltage fast response. That is, the first isolation operational amplifier can quickly output the first sampling signal to the first switching circuit based on the signal at the input terminal. Furthermore, the first isolation operational amplifier can further effectively suppress common-mode noise, improve the stability and accuracy of the output first sampling signal, thereby improving the sampling reliability of the first sampling circuit, and thus improving the detection reliability of subsequent control based on the first sampling signal to detect the voltage of the high-voltage bus.

[0023] Secondly, embodiments of this application provide a vehicle including the detection system described in any optional manner in the first aspect, wherein the detection system is connected to a high-voltage bus. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of a vehicle provided in an embodiment of this application; Figure 2 This is a schematic diagram of a detection system provided in an embodiment of this application; Figure 3 This is a schematic diagram of a detection system provided in an embodiment of this application; Figure 4 This is a schematic diagram illustrating the relationship between a sampling signal and time, provided in an embodiment of this application. Figure 5 This is a schematic diagram of another detection system provided in an embodiment of this application; Figure 6 This is a schematic diagram of another detection system provided in the embodiments of this application; Figure 7 This is a circuit diagram of a detection system provided in an embodiment of this application; Figure 8 This is a circuit diagram of another detection system provided in an embodiment of this application; Figure 9 This is a circuit diagram of another detection system provided in the embodiments of this application.

[0025] 1. Detection system; 11. First sampling circuit; 111. First sampling module; 112. First filter; 12. Second sampling circuit; 121. Second sampling module; 122. Second filter; 13. Controller; 14. First switching circuit; 15. Second switching circuit; 16. First filter circuit; 17. Second filter circuit; ADC1, first port; ADC2, second port; HV, High Voltage Busbar; U1, First Isolation Operational Amplifier; U2, Second Isolation Operational Amplifier; R1, First Resistor; R2, Second Resistor; R3, Third Resistor; R4, Fourth Resistor; R5, Fifth Resistor; R6, Sixth Resistor; C1, First Capacitor; C2, Second Capacitor; C3, Third Capacitor; IN1, First Sampling Signal; IN2, Second Sampling Signal; L1, First Coil; L2, Second Coil; SPDT1, First Single-Pole Double-Throw Switch; SPDT2, Second Single-Pole Double-Throw Switch. Detailed Implementation

[0026] The technical solutions in this application will be clearly and thoroughly described below with reference to the accompanying drawings. In the description of the embodiments of this application, unless otherwise stated, " / " means "or," for example, A / B can mean A or B. "And / or" in the text is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Furthermore, in the description of the embodiments of this application, "multiple" refers to two or more than two.

[0027] Hereinafter, the terms "first" and "second" are used for descriptive purposes only and should not be construed as implying or suggesting relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature.

[0028] New energy vehicles are widely replacing internal combustion engine vehicles in various scenarios. Compared to internal combustion engine vehicles, new energy vehicles produce less noise and do not directly emit exhaust fumes, making them more environmentally friendly. Furthermore, new energy vehicles are more intelligent, have higher energy conversion efficiency, and lower maintenance costs, leading to a growing number of people using them as their mode of transportation. New energy vehicles typically include a power battery to provide power to the vehicle and drive motor. For example, the power battery outputs direct current (DC) to the motor via a high-voltage bus. The motor controller converts this DC power into three-phase alternating current (AC) to power the drive motor, according to the target torque and speed settings sent by the Vehicle Control Unit (VCU). This AC power controls the drive motor to perform functions such as starting, acceleration, deceleration, braking, and energy recovery, ensuring the normal operation of the vehicle.

[0029] To ensure power supply reliability, the voltage of the high-voltage busbar needs to be monitored. Currently, voltage detection systems are typically installed to monitor the voltage of the high-voltage busbar. However, during use, the electronic components in these systems may fail. Damage to these components can affect the detection results and even lead to the failure of the entire system. Furthermore, current technologies cannot accurately distinguish between a high-voltage busbar fault and a voltage detection system fault, potentially leading to detection errors. For example, assuming the high-voltage busbar is normal but the voltage detection system is malfunctioning, the detected voltage value may be too high or too low. In this case, the system might detect an abnormal voltage value even if the high-voltage busbar is not faulty, leading to unnecessary protection actions (such as power outages, alarms, and shutdowns), affecting the normal operation of the vehicle. Conversely, if the fault is in the voltage detection system, current technologies cannot determine the cause of the failure, such as an open circuit or short circuit in the voltage divider resistor. In other words, current technologies cannot accurately pinpoint the fault location within the voltage detection system.

[0030] This application provides a detection system and a vehicle. When an anomaly is detected, the system can accurately identify whether it is a high-voltage power supply failure or a sampling circuit failure by controlling the conduction state of the first and second switching circuits, thereby reducing the false alarm rate, indicating the availability of the system, and ensuring the detection reliability of the detection system.

[0031] The detection system and vehicle provided in the embodiments of this application will be described exemplarily below with reference to the accompanying drawings.

[0032] This application provides a vehicle, which includes a high-voltage bus HV and a detection system 1 for the high-voltage bus HV. The detection system 1 is connected to the positive terminal HV+ and the negative terminal HV- of the high-voltage bus HV. The detection system 1 can detect the voltage of the high-voltage bus HV to detect and verify the power supply to the high-voltage bus HV based on the voltage.

[0033] In one example, such as Figure 2As shown, the detection system 1 includes a first sampling circuit 11, a second sampling circuit 12, and a controller 13. The input terminal of the first sampling circuit 11 is connected to the high-voltage bus HV; specifically, the input terminal of the first sampling circuit 11 is connected to the positive terminal HV+ and the negative terminal HV- of the high-voltage bus HV. The input terminal of the second sampling circuit 12 is connected to the high-voltage bus HV; specifically, the input terminal of the second sampling circuit 12 is connected to the positive terminal HV+ and the negative terminal HV- of the high-voltage bus HV. The output terminals of both the first sampling circuit 11 and the second sampling circuit 12 are connected to the controller 13. Specifically, the controller 13 includes a first port ADC1 and a second port ADC2. The first port ADC1 is connected to the first sampling circuit 11, and the second port ADC2 is connected to the second sampling circuit 12.

[0034] In this example, the first sampling circuit 11 is used to output a first sampling signal IN1 to the controller 13 based on the bus voltage HV, and the second sampling circuit 12 is used to output a second sampling signal IN2 to the controller 13 based on the bus voltage HV. The controller 13 can determine the voltage of the high-voltage bus HV based on the first sampling signal IN1 or the second sampling signal IN2.

[0035] It is understandable that the first sampling circuit 11 and the second sampling circuit 12 are designated as the main sampling circuit and the secondary sampling circuit, respectively. The first sampling circuit 11 is set as the main sampling circuit, and the second sampling circuit 12 as the secondary sampling circuit. During the detection process, the controller 13 receives two sampling signals from the main sampling circuit and the secondary sampling circuit in real time. Under normal circumstances, i.e., when the main sampling circuit is functioning correctly, the controller 13 will only determine the voltage of the high-voltage bus HV based on the first sampling signal IN1 output by the main sampling circuit. At this time, the second sampling signal IN2 output by the secondary sampling circuit is only used for monitoring. When the main sampling circuit malfunctions, the controller 13 can automatically switch to the secondary sampling circuit to ensure the continuity and reliability of the detection. Similarly, when the first sampling circuit 11 is set as the secondary sampling circuit and the second sampling circuit 12 as the main sampling circuit, the specific detection logic can be referred to the detection logic described above, and will not be elaborated further.

[0036] Thus, the first sampling circuit 11 and the second sampling circuit 12 employ a redundancy mechanism, with one sampling circuit designated as the primary sampling circuit and the other as the secondary sampling circuit. Under normal circumstances, the controller 13 can detect the voltage of the high-voltage bus HV based on the sampling signal provided by the primary sampling circuit. When the primary sampling circuit fails, the controller 13 can automatically switch to the secondary sampling circuit. That is, the controller 13 can then detect the voltage of the high-voltage bus HV based on the sampling signal provided by the secondary sampling circuit. This allows the detection system 1 to continue operating and detecting even when a partial fault occurs, avoiding the problem of the entire system crashing and shutting down due to a sampling circuit failure, thereby ensuring the continuity and reliability of the detection system 1.

[0037] Furthermore, when the controller 13 determines an anomaly based on the first sampling signal IN1 and the second sampling signal IN2, the anomaly could be a high-voltage bus HV anomaly or a fault in the sampling circuit itself. To enable the controller 13 provided in this application to accurately identify whether the fault is in the high-voltage bus HV or the sampling circuit, in one example, such as... Figure 3 As shown, the detection system 1 provided in this application further includes a first switching circuit 14 and a second switching circuit 15. The first terminal of the first switching circuit 14 is connected to the output terminal of the first sampling circuit 11, and the second terminal of the first switching circuit 14 is connected to a reference voltage V0. The first terminal of the second switching circuit 15 is connected to the output terminal of the second sampling circuit 12, and the second terminal of the second switching circuit 15 is connected to the reference voltage V0.

[0038] In this example, controller 13 is connected to the third terminal of the first switching circuit 14 and the third terminal of the second switching circuit 15 to receive the first sampling signal IN1 and the second sampling signal IN2, and to determine the current voltage of the high-voltage bus HV based on the first sampling signal IN1 and the second sampling signal IN2. Controller 13 is also connected to the controlled terminal of the first switching circuit 14 and the controlled terminal of the second switching circuit 15, meaning controller 13 can also control the conduction state of the first switching circuit 14 and the second switching circuit 15 based on the first sampling signal IN1 and the second sampling signal IN2. Specifically, controller 13 can output control signal KY1 to the first switching circuit 14 and the second switching circuit 15 to control the first switching circuit 14 and the second switching circuit 15 to be in different conduction states.

[0039] The first switching circuit 14 and the second switching circuit 15 each have a first conducting state and a second conducting state. When the first switching circuit 14 is in the first conducting state, its first terminal is connected to its third terminal, and it is connected to the branch containing the first sampling circuit 11, meaning the detection system performs voltage detection. When the first switching circuit 14 is in the second conducting state, its second terminal is connected to its third terminal, and the voltage applied to it is the reference voltage V0, meaning the detection system performs fault location. Similarly, when the second switching circuit 15 is in the first conducting state, its first terminal is connected to its third terminal, and it is connected to the branch containing the second sampling circuit 12. When the second switching circuit 15 is in the second conducting state, its second terminal is connected to its third terminal, and the voltage applied to it is the reference voltage V0.

[0040] For example, when the controller 13 determines that there is no abnormality based on the first sampling signal IN1 and the second sampling signal IN2, the controller 13 controls the first switching circuit 14 and the second switching circuit 15 to remain in the first conducting state. At this time, the signals output to the controller by the first switching circuit 14 and the second switching circuit 15 are the first sampling signal IN1 and the second sampling signal IN2 generated based on the voltage of the high-voltage bus HV. At this time, the controller 13 continuously detects the output voltage of the high-voltage bus HV based on the first sampling signal IN1 and the second sampling signal IN2.

[0041] For example, when controller 13 determines an anomaly based on the first sampling signal IN1 and the second sampling signal IN2, in order to determine whether the anomaly is in the high-voltage bus HV or the sampling circuit, controller 13 will control the first switching circuit 14 and the second switching circuit 15 to a second conducting state. When the first switching circuit 14 and the second switching circuit 15 are in the second conducting state, controller 13 is disconnected from the first sampling circuit 11 and the second sampling circuit 12. The signals received by controller 13 are the first detection signal generated by the first switching circuit 14 based on the reference voltage V0, and the second detection signal generated by the second switching circuit 15 based on the reference voltage V0. Controller 13 can determine whether there is an anomaly in the branch where the first switching circuit 14 and controller 13 are located, and the devices in the branch, based on the first detection signal. If there is an anomaly, it means that the anomaly is in that branch. If there is no anomaly in the branch, controller 13 will troubleshoot the first sampling circuit 11 to determine whether the first sampling circuit 11 is faulty. Similarly, controller 13 determines whether there is a fault in the branch and the second sampling circuit 12 based on the second detection signal in the same way.

[0042] Understandably, when the first switching circuit 14 and the second switching circuit 15 are in the second conducting state, if the branch containing the first switching circuit 14 and the controller 13, and the devices on that branch, are abnormal, it means that the abnormality currently exists only in that branch and its devices. Furthermore, to ensure the reliability of the troubleshooting, the controller 13 can also perform fault checks on the first sampling circuit 11 and the second sampling circuit 12 to avoid all branches being abnormal. If the controller 13 determines, based on the detection results, that the fault is in the branch or a device on that branch, it will promptly report it so that the abnormal branch and its devices can be maintained.

[0043] When the first switching circuit 14 and the second switching circuit 15 are in the second conducting state, if the branch where the first switching circuit 14 and the controller 13 are located, and the components on that branch are normal, and the branch where the second switching circuit 15 and the controller 13 are located, and the components on that branch are normal, it means that the abnormality at this time may be the first sampling circuit 11, the second sampling circuit 12, or the high-voltage power supply 2. The controller 13 then performs fault diagnosis on the first sampling circuit 11 and the second sampling circuit 12. If both the first sampling circuit 11 and the second sampling circuit 12 are normal at this time, the voltage detected by the controller 13 is the same as the actual voltage value corresponding to the reference voltage V0, or the same as the preset detection threshold in the controller 13. Based on the first detection signal and the second detection signal at this time, the controller 13 determines that there is no abnormality in the branch and the sampling circuit, and then determines that the high-voltage bus HV is abnormal. At this time, the system triggers a protection action to prevent the high-voltage bus HV abnormality from affecting the normal use of the vehicle.

[0044] If either the first sampling circuit 11 or the second sampling circuit 12 malfunctions, the voltage output to the controller 13 will differ from the actual voltage value corresponding to the reference voltage V0. For example, the voltage received by the controller 13 may be 0, or the voltage may deviate from the reference voltage V0, or the voltage may differ from the preset detection threshold within the controller 13. The controller 13 determines the corresponding branch based on the detection signal or determines the sampling circuit malfunction based on the voltage. Simultaneously, the controller 13 can control another sampling circuit that is not malfunctioning to be in the first conducting state, enabling the controller 13 to determine whether the high-voltage bus HV is malfunctioning based on the sampling signal output by the other sampling circuit, thus ensuring detection continuity and avoiding detection interruption. Therefore, when the first switching circuit 14 is in the second conducting state, the controller 13 can determine whether the high-voltage bus HV, the sampling circuit, or the branch is malfunctioning based on the first and second detection signals, and can locate the specific sampling circuit and branch with the malfunction when the sampling circuit or branch is malfunctioning. At this time, if the first switching circuit 14 and the second switching circuit 15 switch back to the first conduction mode, the controller 13 determines, based on the first sampling signal IN1 and the second sampling signal IN2, that the anomaly is a sampling circuit or branch anomaly, rather than a high-voltage bus HV anomaly. In this case, maintenance is performed on the abnormal sampling circuit or branch, and another normal sampling circuit and branch are sampled to continue monitoring the high-voltage bus HV without shutdown. This avoids the problem in related technologies where it is impossible to accurately identify whether the fault is in the high-voltage bus HV or the sampling circuit, leading to false voltage alarms, triggering unnecessary protection actions, and affecting the normal operation of the entire vehicle.

[0045] In this example, after determining that a faulty sampling circuit exists based on the first and second detection signals, the controller 13 can also locate the specific fault point in the faulty sampling circuit based on the reference voltage V0. For example, the controller 13 has preset voltage thresholds for each device in the sampling circuit under normal conditions. When an abnormality occurs in the sampling circuit, the voltage of the corresponding abnormal device in the sampling circuit will also deviate. The controller 13 compares the voltage corresponding to the detected signal at this time with the voltage threshold to determine the device with the deviation, thereby achieving accurate location of the fault point in the abnormal sampling circuit.

[0046] In summary, when controller 13 determines that no abnormality exists based on the first sampling signal IN1 and the second sampling signal IN2, the first switching circuit 14 and the second switching circuit 15 are in the first conducting state. At this time, controller 13 performs real-time detection of the voltage of the high-voltage bus HV based on the first sampling signal IN1 and the second sampling signal IN2 to achieve the detection of the high-voltage bus HV. At this time, the detection system implements the voltage detection function of the high-voltage bus HV. When controller 13 determines that an abnormality exists based on the first sampling signal IN1 and the second sampling signal IN2, controller 13 will control the first switching circuit 14 and the second switching circuit 15 to the second conducting state. Controller 13 will receive the first detection signal and the second detection signal generated based on the reference voltage V0. Controller 13 can determine whether there is a fault in the sampling circuit and the branch based on the first detection signal and the second detection signal. At this time, the detection system implements the fault location function. If it is determined that there is no abnormality in the sampling circuit and the branch based on the detection signal, it means that there is an abnormality in the high-voltage bus HV. At this time, the system triggers protection actions (such as power failure, alarm, shutdown, etc.) to prevent the high-voltage bus HV abnormality from affecting the normal use of the vehicle. If the detection signal determines that one of the sampling circuits or branches is abnormal, the controller 13 can control the other sampling circuit or branch without abnormality to be in the first conducting state to continue monitoring the high-voltage bus HV and determine whether there is an abnormality in the high-voltage bus HV, thus ensuring the continuity of the high-voltage bus HV detection and avoiding detection interruption. If the detection signal determines that both sampling circuits or both branches are abnormal, the detection system cannot continue to detect the high-voltage bus HV and will report the issue for repair of the sampling circuit or branch. In this way, by controlling the conducting state of the first switching circuit 14 and the second switching circuit 15, this application can realize the detection of the high-voltage bus HV and accurately identify whether the abnormality is a high-voltage bus HV fault or a sampling circuit fault when an abnormality is detected. This avoids the problem of false voltage values ​​caused by sampling circuit faults, triggering unnecessary protection actions (such as power failure, alarms, etc.), affecting the normal use of the vehicle, thereby improving system availability to 100%, reducing the false alarm rate to >99%, and ensuring the detection reliability of the detection system and the reliability of vehicle use.

[0047] It is worth noting that the first switching circuit 14 and the second switching circuit 15 in this application can be connected to the same control signal KY1 or different control signals. When the first switching circuit 14 and the second switching circuit 15 are connected to the same control signal KY1, the switching synchronization of the first switching circuit 14 and the second switching circuit 15 is high. When the first switching circuit 14 and the second switching circuit 15 are connected to different control signals, if one of the sampling circuits malfunctions, the corresponding switching circuit remains in the second conducting state. That is, the malfunctioning sampling circuit is not connected to the detection system 1, avoiding the problem of the sampling circuit being severely burned out due to continued use despite the sampling circuit failure. At this time, the controller 13 can control the switching circuit corresponding to the other sampling circuit that is not malfunctioning to be in the first conducting state, that is, the controller 13 can continue to detect the high-voltage bus HV based on the normal sampling circuit. The specific settings can be configured according to actual needs, and this application does not impose specific restrictions on this.

[0048] In order for the controller 13 to determine that an anomaly exists based on the first sampling signal IN1 and the second sampling signal IN2, in one example, the controller 13 is used to generate an error signal based on the first sampling signal and the second sampling signal IN2, and when the error signal is greater than or equal to the error threshold, control the second terminal of the first switching circuit 14 to be connected to the third terminal of the first switching circuit 14, and control the second terminal of the second switching circuit 15 to be connected to the third terminal of the second switching circuit 15.

[0049] It is worth noting that after receiving the first sampling signal IN1, the controller 13 will convert the first sampling signal IN1 into the corresponding actual voltage value Vol13 according to a preset proportional algorithm (voltage divider algorithm and digital-to-analog conversion). At the same time, a voltage offset EFF1 will be added to calculate the true voltage value Vol12. This actual voltage value Vol12 is the actual voltage of the high-voltage bus HV collected by the first sampling circuit 11 at this time. Similarly, after receiving the second sampling signal IN2, the controller 13 will also convert it into the corresponding actual voltage value Vol23, add a voltage offset EFF2, and calculate the true voltage value Vol22.

[0050] The controller 13 first calculates the voltage difference between the first sampled signal IN1 and the second sampled signal IN2, and then calculates the error signal based on the ratio of the voltage difference to the first sampled signal IN1. In other words, the controller 13 performs a differential comparison between the first sampled signal IN1 and the second sampled signal IN2. Specifically, the controller 13 generates corresponding actual voltage values ​​Vol12 and Vol22 based on the received first sampled signal IN1 and second sampled signal IN2, calculates the difference between Vol12 and Vol22, and then compares this difference with Vol12 to obtain the error signal. That is, the error signal can be obtained according to formula (1): Vc=(Vol12-Vol22) / Vol12(1) Where Vc is the error signal, Vol12 is the actual voltage value calculated based on the first sampling signal IN1, and Vol22 is the actual voltage value calculated based on the second sampling signal IN2.

[0051] The controller 13 has a preset error threshold, for example, such as Figure 4 As shown, the error threshold is set to ±2%. Figure 4 The horizontal axis represents the sampling time, and the vertical axis represents the voltage value. Vin1 is the actual voltage value corresponding to the first sampling signal IN1, and Vin2 is the actual voltage value corresponding to the second sampling signal IN2. When the error signal calculated by the controller 13 is greater than or equal to the error threshold (i.e., ≥ ±2%), it indicates that a fault exists in the detection system 1. At this time, the difference threshold mechanism is triggered, and the controller 13 controls the first switching circuit 14 and the second switching circuit 15 to be in the second conduction state. For example, Figure 4 During the time periods t5~t9 and t11~t17, the difference threshold triggering mechanism is met, and the system enters the "cross-validation + fault diagnosis mechanism" stage, that is, the first switching circuit 14 and the second switching circuit 15 are controlled to be in the second conduction state, and the fault code is recorded.

[0052] In this example, controller 13 calculates an error signal based on the actual voltage values ​​Vol12 and Vol22. When the error signal is greater than or equal to the error threshold, it indicates that an anomaly exists in detection system 1. Controller 13 controls the first switching circuit 14 and the second switching circuit 15 to a second conducting state, enabling controller 13 to locate the specific fault point. Thus, this application can determine the presence of an anomaly through the error signal, providing reliable support for subsequent fault location.

[0053] During the detection process, there may be deviations in the error signal due to external interference. In order to further improve the reliability of the detection, the difference threshold mechanism is triggered when the error signal is greater than or equal to the error threshold and occurs three times in a row.

[0054] The detection system 1 can determine the operating conditions of the secondary sampling circuit under simple working conditions through software logic algorithms. To avoid frequent switching between the faulty and normal sampling circuits, which could lead to frequent triggering of bus voltage (HV) related fault protection strategies and false alarms, the system uses software logic algorithms. In one example, such as... Figure 4 As shown, the controller 13 is also used to generate a first voltage value Vol15 according to the first sampling signal IN1 and a second voltage value Vol25 according to the second sampling signal IN2, and select one of the first sampling circuit 11 and the second sampling circuit 12 as the main sampling circuit and the other as the sub-sampling circuit based on the first voltage value Vol15, the second voltage value Vol25 and the reference voltage V0.

[0055] In this example, the controller 13 can determine the "true" and "false" sampling circuits based on the first voltage value Vol15, the second voltage value Vol25, and the reference voltage V0. Specifically, when the first voltage value Vol15 received by the controller 13 is close to the reference voltage V0, and the deviation between the second voltage value Vol25 and the reference voltage V0 is large, the controller determines that the first sampling circuit 11 corresponding to the first voltage value Vol15 is the "true" sampling circuit, and the second sampling circuit 12 is the "false" sampling circuit. The controller 13 selects the first sampling circuit 11 as the main sampling circuit and the second sampling circuit 12 as the secondary sampling circuit. The reverse is also true, and will not be elaborated further.

[0056] Thus, the controller 13 can determine the "true" sampling circuit and the "false" sampling circuit based on the first voltage value Vol15, the second voltage value Vol25, and the reference voltage V0. Based on the detection results, it selects the "true" sampling circuit as the main sampling circuit and the "false" sampling circuit as the secondary sampling circuit. This avoids the possibility of the main / secondary sampling circuit switching back and forth, which could lead to frequent fault protection strategies and false alarms, thereby improving detection reliability. Secondly, this application can switch to the correct sampling circuit for voltage sampling, achieving the purpose of non-stop detection.

[0057] It is worth noting that this application can also realize a power-on voltage offset self-test function through the controller 13, the first switching circuit 14, and the second switching circuit 15. Specifically, after the controller 13 is initialized, it controls the first switching circuit 14 and the second switching circuit 15 to be in a second conduction state, so that the first switching circuit 14 and the second switching circuit 15 are connected to the reference voltage V0. The first port ADC1 and the second port ADC2 of the controller 13 are connected to the voltage value, and the voltage value is converted into actual voltage values ​​Vol1 and Vol2 according to the proportional algorithm, and the voltage offset is calculated. The voltage offset is used to determine whether there is a voltage offset at this time. Specifically, the voltage offset can be calculated according to... The calculation is based on EFF1 / EFF2 = 2.5V - Vol1 / Vol2. If the voltage offset EFF1 / EFF2 > the offset threshold (e.g., ±0.5V), it indicates a voltage offset. When a voltage offset is detected before power-on, it indicates an abnormality in the sampling circuit. This triggers a fault diagnosis mechanism and records a fault code to locate the fault in the sampling circuit. This process does not stop the system. Furthermore, to improve detection reliability, this process can be repeated multiple times, for example, 10 times. The average of the 10 voltage offsets is then compared to the offset threshold.

[0058] Understandably, when the power-on voltage offset self-test function detects a voltage offset, the detection system 1 will first check for faults in the sampling circuit. When the power-on voltage offset self-test function detects no voltage offset, it means that there is no fault in the sampling circuit at this time, that is, the power-on voltage offset self-test function is completed. Only after the power-on voltage offset self-test function is completed will the detection system 1 test the high-voltage bus HV.

[0059] In one example, such as Figure 5 As shown, the first switching circuit 14 includes a voltage source U and a first switching module 141. The voltage source U is connected to the second terminal of the second switching circuit 15 and is used to output a reference voltage V0. The first terminal of the first switching module 141 serves as the first terminal of the first switching circuit 14 and is connected to the output terminal of the first sampling circuit 11. The second terminal of the first switching module 141 serves as the second terminal of the first switching circuit 14 and is connected to the voltage source U. The third terminal of the first switching module 141 serves as the third terminal of the first switching circuit 14 and is connected to the controller 13. The controlled terminal of the first switching module 141 serves as the controlled terminal of the first switching circuit 14 and is connected to the controller 13.

[0060] In this example, the conduction state of the first switching circuit 14 can be switched by changing the conduction state of the first switching module 141, providing high switching flexibility. Furthermore, a voltage source U is set to provide a stable reference voltage V0 for the detection system 1, thereby ensuring the reliability of subsequent fault detection and location of the sampling circuit based on this reference voltage V0.

[0061] In one example, such as Figure 6As shown, the first switch module 141 includes a first relay, which includes a first coil L1 and a first single-pole double-throw (SPDT) switch. One end of the first coil L1 is grounded, and the other end of the first coil L1 serves as the controlled terminal of the first switch module 141 and is connected to the controller 13. The common terminal of the first SPDT switch 1 serves as the third terminal of the first switch module 141 and is connected to the controller 13. The first switching terminal of the first SPDT switch 1 serves as the first terminal of the first switch module 141 and is connected to the output terminal of the first sampling circuit 11. The second switching terminal of the first SPDT switch 1 serves as the second terminal of the first switch module 141 and is connected to the voltage source U.

[0062] In this example, controller 13 outputs a control signal KY1 to the first coil L1 to control the energization state of the first coil L1, thereby changing the conduction state of the first single-pole double-throw switch SPDT1. For example, when the first switch module 141 needs to switch to the second conduction state, controller 13 outputs a high-level control signal KY1 to the first coil L1, causing the first coil L1 to be energized and generate a magnetic field, which in turn drives the internal mechanical contacts to change the conduction state of the first single-pole double-throw switch SPDT1, thereby realizing the automatic switching of the overall conduction state of the first switching circuit 14.

[0063] Thus, by changing the energized state of the first coil L1, the overall conduction state of the first switching circuit 14 can be switched, providing high switching flexibility. Secondly, the first coil L1 and the first single-pole double-throw switch SPDT1 in the first relay are physically isolated and have no direct electrical connection, effectively preventing noise interference and improving the anti-interference capability of the first switching circuit 14, thereby enhancing the overall safety and reliability of the system.

[0064] Optionally, the first switch module 141 may include two independent switches, with the controlled terminals of the two independent switches connected to the controller 13. It is worth noting that when the first switch module 141 consists of two independent switches, the on / off states of the two switches are always opposite; that is, when one is on, the other is off, to achieve different output paths. The first switch module 141 provided in this application can use the aforementioned devices or other devices or circuits capable of selecting different output paths; this application does not impose specific limitations in this regard.

[0065] In one example, such as Figure 5As shown, the second switching circuit 15 includes a second switching module 151. The first end of the second switching module 151 serves as the first end of the second switching circuit 15 and is connected to the output end of the second sampling circuit 12. The second end of the second switching module 151 serves as the second end of the second switching circuit 15 and is connected to the voltage source U. The third end of the second switching module 151 serves as the third end of the second switching circuit 15 and is connected to the controller 13. The controlled end of the second switching module 151 serves as the controlled end of the second switching circuit 15 and is connected to the controller 13.

[0066] It is worth noting that the second switch module 151 achieves the same effect as the first switch module 141. That is, by switching the conduction state of the second switch module 151, the conduction state of the second switching circuit 15 can be switched, providing high flexibility. Furthermore, the second switch module 151 and the first switch module 141 share the same voltage source U, eliminating the need to set a separate voltage source for each switch module and saving manufacturing costs.

[0067] In one example, such as Figure 6 As shown, the second switch module 151 includes a second relay, which includes a second coil L2 and a second single-pole double-throw switch SPDT2. One end of the second coil L2 is grounded, and the other end of the second coil L2 serves as the controlled terminal of the second switch module 151 and is connected to the controller 13. The common terminal of the second single-pole double-throw switch SPDT2 serves as the third terminal of the second switch module 151 and is connected to the controller 13. The first switching terminal of the second single-pole double-throw switch SPDT2 serves as the first terminal of the second switch module 151 and is connected to the output terminal of the second sampling circuit 12. The second switching terminal of the second single-pole double-throw switch SPDT2 serves as the second terminal of the second switch module 151 and is connected to the voltage source U.

[0068] It is worth noting that the second switch module 151 and the first switch module 141 adopt the same structure and achieve the same effect. That is, by changing the energized state of the second coil L2, the overall conduction state of the second switching circuit 15 can be switched, providing high switching flexibility. Furthermore, the second coil L2 and the second single-pole double-throw switch SPDT2 in the second relay are physically isolated and have no direct electrical connection, effectively preventing noise interference and improving the anti-interference capability of the second switching circuit 15, thereby enhancing the overall safety and reliability of the system.

[0069] It is worth noting that the first switching circuit 14 and the second switching circuit 15 provided in this application are both in the first conducting state before receiving the control signal KY1, that is, connected to the high-voltage bus HV.

[0070] The high-voltage bus HV is connected to the drive motor. The inverter of the drive motor has high-frequency switching noise, such as pulse width modulation (PWM) harmonics. These PWM harmonics are easily coupled into the sampling circuits (i.e., the first sampling circuit 11 and the second sampling circuit 12), and the common-mode interference may reach the kV level, making it noise-sensitive. Secondly, the sampling circuits may also be at risk of isolation failure, making it difficult to achieve fast high-voltage response. To filter out PWM harmonics and improve the sampling reliability of the sampling circuits, in one example, such as... Figure 7 As shown, the first sampling circuit 11 includes a first sampling module 111, a first filter 112, and a first isolation operational amplifier U1. The first terminal of the first sampling module 111 serves as the input terminal of the first sampling circuit 11 and is connected to the positive terminal HV+ of the high-voltage bus HV. The first terminal of the first filter 112 is connected to the second terminal of the first sampling module 111, and the second terminal of the first filter 112 is connected to the negative terminal HV- of the high-voltage bus HV. The non-inverting input terminal of the first isolation operational amplifier U1 is connected to the first terminal of the first filter 112, and the inverting input terminal of the first isolation operational amplifier U1 is connected to the second terminal of the first filter 112. The output terminal of the first isolation operational amplifier U1 serves as the output terminal of the first sampling circuit 11 and is connected to the first terminal of the first switching circuit 14 (i.e., one end of the first switching module 141 shown in the figure).

[0071] In this example, the first sampling module 111 samples the voltage of the high-voltage bus HV and outputs it to the first filter 112. The first filter 112 filters the signal acquired by the first sampling module 111 to remove PWM noise. The signal with the PWM noise removed is output to the first isolation operational amplifier U1. The first isolation operational amplifier U1 can achieve electrical isolation between the input and output terminals, and at the same time achieve high-voltage fast response. That is, the first isolation operational amplifier U1 can quickly output the first sampling signal IN1 to the first switching circuit 14 based on the signal at the input terminal. Furthermore, the first isolation operational amplifier U1 can also effectively suppress common-mode noise, improve the stability and accuracy of the output first sampling signal IN1, thereby improving the sampling reliability of the first sampling circuit 11, and thus improving the detection reliability of the subsequent controller 13 in detecting the voltage of the high-voltage bus HV based on the first sampling signal IN1.

[0072] In one example, such as Figure 8 As shown, the first sampling module 111 includes a plurality of first resistors R1 connected in series. The first end of the first resistor R1 that is not connected to the other first resistors R1 serves as the first end of the first sampling module 111 and is connected to the positive terminal HV+ of the high voltage bus HV. The last end of the first resistor R1 that is not connected to the other first resistors R1 serves as the second end of the first sampling module 111 and is connected to the first end of the first filter 112.

[0073] In this example, the first resistor R1 connected in series samples the voltage of the high-voltage DC bus HV. By connecting multiple first resistors R1 in series, the voltage of the high-voltage DC bus HV can be adjusted proportionally and output to the first filter 112, thereby achieving high-precision sampling. Furthermore, the circuit structure of the first sampling module 111, composed of multiple first resistors R1 connected in series, is simple, highly reliable, and easy to maintain and debug.

[0074] Optionally, the first resistor R1 is a temperature-compensated thin-film resistor with a temperature tolerance of ±10ppm / ℃. The temperature drift of the temperature-compensated thin-film resistor is extremely low, meaning that when the ambient temperature changes, the resistance value of the temperature-compensated resistor changes less, i.e., it is less affected by temperature drift. This ensures the sampling accuracy of the temperature-compensated thin-film resistor and improves the sampling precision and accuracy of the first sampling module 111.

[0075] In one example, such as Figure 8 As shown, the first filter 112 includes a second resistor R2 and a first capacitor C1. One end of the second resistor R2 serves as the first terminal of the first filter 112, and is connected to one end of the first resistor R1 and the first plate of the first capacitor C1. The other end of the second resistor R2 serves as the second terminal of the first filter 112, and is connected to the negative terminal of the high-voltage bus HV and the second plate of the first capacitor C1.

[0076] In this example, the second resistor R2 and the first capacitor C1 form an RC filter. The RC filter can filter the signal output from the first sampling module 111 to remove high-frequency spikes and PWM noise in the circuit, prevent circuit oscillation, and improve the integrity and accuracy of the signal output to the first isolation operational amplifier U1. Secondly, the two plates of the first capacitor C1 are connected to the two input terminals of the first isolation operational amplifier U1, forming a capacitor-isolated high-speed amplifier, further improving the electrical isolation effect and ensuring the reliability of the first sampling signal IN1 output to the subsequent controller 13.

[0077] Optionally, the second resistor R2 is a temperature-compensated thin-film resistor with a tolerance of ±10ppm / ℃. The temperature drift of the temperature-compensated thin-film resistor is extremely low, meaning that its resistance changes less when the ambient temperature changes. This ensures the sampling accuracy of the temperature-compensated thin-film resistor, making it less affected by temperature drift and improving the precision and accuracy of the transmitted signal.

[0078] Furthermore, to improve the reliability of the signal output from the first switching circuit 14 to the controller 13, in one example, such as Figure 9As shown, the detection system 1 also includes a first filter circuit 16. The first filter circuit 16 is connected in series between the third terminal of the first switching circuit 14 and the controller 13.

[0079] In this example, the first filtering circuit 16 can filter the signal output by the first switching circuit 14 again to further improve the integrity and accuracy of the first sampling signal IN1 output to the controller 13, and improve the reliability of the controller 13 in detecting based on the first sampling signal IN1.

[0080] Optional, such as Figure 9 As shown, the first filter circuit 16 also includes a third resistor R3 and a second capacitor C2. One end of the third resistor R3 is connected to the third terminal of the first switching circuit 14, and the other end of the third resistor R3 is connected to the first port ADC1 and the first plate of the second capacitor C2. The second plate of the second capacitor C2 is grounded.

[0081] In this example, the third resistor R3 and the second capacitor C2 constitute an RC filter. The RC filter can further filter the signal output from the first switching circuit 14 to improve the integrity and accuracy of the first sampling signal IN1 output to the controller 13. Thus, the first sampling signal IN1 output from the first sampling circuit 11 is filtered by two RC filters before being output to the controller 13. This means the first sampling circuit 11 has second-order anti-interference capability, improving the reliability of the first sampling signal IN1 output from the first sampling circuit 11 to the controller 13. This, in turn, improves the reliability of the controller 13's detection of the high-voltage bus HV based on the first sampling signal IN1.

[0082] In one example, such as Figure 7 As shown, the second sampling circuit 12 includes a second sampling module 121, a second filter 122, and a second isolation operational amplifier U2. The first terminal of the second sampling module 121 serves as the input terminal of the second sampling circuit 12 and is connected to the positive terminal HV+ of the high-voltage bus HV. The first terminal of the second filter 122 is connected to the second terminal of the second sampling module 121, and the second terminal of the second filter 122 is connected to the negative terminal HV- of the high-voltage bus HV. The non-inverting input terminal of the second isolation operational amplifier U2 is connected to the first terminal of the second filter 122, and the inverting input terminal of the second isolation operational amplifier U2 is connected to the second terminal of the second filter 122. The output terminal of the second isolation operational amplifier U2 serves as the output terminal of the second sampling circuit 12 and is connected to the first terminal of the second switching circuit 15 (i.e., one end of the second switching module 151 as shown in the figure).

[0083] In this example, the second sampling module 121 samples the voltage of the high-voltage bus HV and outputs it to the second filter 122. The second filter 122 filters the signal acquired by the second sampling module 121 to remove PWM noise. The signal with the PWM noise removed is output to the second isolation operational amplifier U2. The second isolation operational amplifier U2 can achieve electrical isolation between the input and output terminals, and at the same time achieve high-voltage fast response. That is, the second isolation operational amplifier U2 can quickly output the second sampling signal IN2 to the second switching circuit 15 based on the signal at the input terminal. Furthermore, the second isolation operational amplifier U2 can further effectively suppress common-mode noise, improve the stability and accuracy of the output second sampling signal IN2, thereby improving the sampling reliability of the second sampling circuit 12, and thus improving the detection reliability of the controller 13 in detecting the voltage of the high-voltage bus HV based on the second sampling signal IN2.

[0084] It is understandable that the second sampling module 121 and the second filter 122 achieve the same effect as the first sampling module 111 and the first filter 112 mentioned above. Correspondingly, as... Figure 8 As shown, the second sampling module 121 may include multiple fourth resistors R4 connected in series. The second filter 122 may include a fifth resistor R5 and a third capacitor C3.

[0085] Furthermore, in order to improve the reliability of the signal output from the second switching circuit 15 to the controller 13, the detection system 1 may also include a second filtering circuit 17, which is connected in series between the third terminal of the second switching circuit 15 and the controller 13.

[0086] In this example, the second filter circuit 17 can filter the signal output by the second switching circuit 15 again to further improve the integrity and accuracy of the second sampling signal IN2 output to the controller 13, and improve the reliability of the controller 13 in detecting based on the second sampling signal IN2.

[0087] It is understandable that the second filter circuit 17 achieves the same effect as the first filter circuit 16 described above, correspondingly, as... Figure 9 As shown, the second filter circuit 17 can be a sixth resistor R6 and a fourth capacitor C4.

[0088] Optionally, the controller 13 can be a microcontroller unit (MCU), and the corresponding MCU is equipped with a first port ADC1 and a second port ADC2.

[0089] In the detection system 1 provided in this application, each resistor can be a temperature-compensated thin-film resistor, resulting in an error of ≤0.25% across the entire temperature range. This is significantly lower than the 1.5%~3% error in related technologies. By using an isolation operational amplifier, the sampling delay can be reduced to <1μs (microseconds) to meet high-frequency control requirements. Furthermore, the isolation operational amplifier enables the detection system 1 to support DC bus voltage inputs of 200V-1500V. Moreover, by using redundant first sampling circuit 11 and second sampling circuit 12, the mean time between failures (MTBF) can be increased to 100,000 hours.

[0090] When the first sampling circuit 11 and the second sampling circuit 12 include the aforementioned devices, the fault diagnosis mechanism provided in this application can locate faults according to Table 1 below. It is worth noting that, in this table, channel 1 represents the sampling voltage value of the first sampling circuit 11 when the first switching circuit 14 is in the first conducting state; channel 2 represents the sampling voltage value of the second sampling circuit 12 when the second switching circuit 15 is in the first conducting state; channel 15 represents the sampling voltage value of the first sampling circuit 11 when the first switching circuit 14 is in the second conducting state; and channel 25 represents the sampling voltage value of the second sampling circuit 12 when the second switching circuit 15 is in the second conducting state. K1 is the voltage conversion ratio of the first sampling circuit 11, and K2 is the voltage conversion ratio of the second sampling circuit 12.

[0091]

[0092] Table 1 Table 1 shows 4, 5, 8, and 11 as abnormalities in the first sampling circuit 11 and its internal components, and 6, 7, 9, and 12 as abnormalities in the second sampling circuit 12 and its internal components. When the first switching circuit 14 and the second switching circuit 15 are in the first conducting state, the controller 13 obtains the voltage values ​​in channels 1 and 2. When the controller 13 determines that an abnormality is detected based on the first sampling signal IN1 and the second sampling signal IN2, the controller 13 controls the first switching circuit 14 and the second switching circuit 15 to be in the second conducting state, and obtains the corresponding voltage values ​​in channels 15 and 25 at this time. The obtained voltage values ​​are then compared with the voltage thresholds in channels 1 and 2 to determine whether the specific fault is in the sampling circuit or the relay. If the current fault is located in the sampling circuit, the controller determines the specific faulty component or fault state in that sampling circuit.

[0093] For example, taking the open circuit of the third resistor R3 in the first sampling circuit 11 as an example, when the controller 13 receives a voltage value of 0V in channel 1 and channel 15, and the voltage value in channel 25 is also 0V, it indicates that the fault point is the third resistor R3 in the first sampling circuit 11, and the fault type is an open circuit of the third resistor R3. It is worth noting that the above are only examples of these fault types, and corresponding fault values ​​can be set based on other fault types. This application does not impose specific limitations on this.

[0094] In summary, when controller 13 determines that no abnormality exists based on the first sampling signal IN1 and the second sampling signal IN2, the first switching circuit 14 and the second switching circuit 15 are in the first conducting state. At this time, controller 13 performs real-time detection of the voltage of the high-voltage bus HV based on the first sampling signal IN1 and the second sampling signal IN2 to achieve the detection of the high-voltage bus HV. At this time, the detection system implements the voltage detection function of the high-voltage bus HV. When controller 13 determines that an abnormality exists based on the first sampling signal IN1 and the second sampling signal IN2, controller 13 will control the first switching circuit 14 and the second switching circuit 15 to the second conducting state. Controller 13 will receive the first detection signal and the second detection signal generated based on the reference voltage V0. Controller 13 can determine whether there is a fault in the sampling circuit and the branch based on the first detection signal and the second detection signal. At this time, the detection system implements the fault location function. If it is determined that there is no abnormality in the sampling circuit and the branch based on the detection signal, it means that there is an abnormality in the high-voltage bus HV. At this time, the system triggers protection actions (such as power failure, alarm, shutdown, etc.) to prevent the high-voltage bus HV abnormality from affecting the normal use of the vehicle. If the detection signal determines that one of the sampling circuits or branches is abnormal, the controller 13 can control the other sampling circuit or branch without abnormality to be in the first conducting state to continue monitoring the high-voltage bus HV and determine whether there is an abnormality in the high-voltage bus HV, thus ensuring the continuity of the high-voltage bus HV detection and avoiding detection interruption. If the detection signal determines that both sampling circuits or both branches are abnormal, the detection system cannot continue to detect the high-voltage bus HV and will report the issue for repair of the sampling circuit or branch. In this way, by controlling the conducting state of the first switching circuit 14 and the second switching circuit 15, this application can realize the detection of the high-voltage bus HV and accurately identify whether the abnormality is a high-voltage bus HV fault or a sampling circuit fault when an abnormality is detected. This avoids the problem of false voltage values ​​caused by sampling circuit faults, triggering unnecessary protection actions (such as power failure, alarms, etc.), affecting the normal use of the vehicle, thereby improving system availability to 100%, reducing the false alarm rate to >99%, and ensuring the detection reliability of the detection system and the reliability of vehicle use.

[0095] Through the above description of the embodiments, those skilled in the art will understand that, for the sake of convenience and brevity, only the division of the above functional modules is used as an example. In actual applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0096] In the embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative. For instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another device, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms.

[0097] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A detection system, characterized in that, The detection system includes: The first sampling circuit has its input terminal connected to the high-voltage bus and is used to output a first sampling signal. The second sampling circuit has its input terminal connected to the high-voltage bus and is used to output a second sampling signal. A first switching circuit, wherein a first terminal of the first switching circuit is connected to the output terminal of the first sampling circuit, and a second terminal of the first switching circuit is connected to a reference voltage. A second switching circuit, wherein a first terminal of the second switching circuit is connected to the output terminal of the second sampling circuit, and a second terminal of the second switching circuit is connected to the reference voltage; and... The controller is connected to the third terminal of the first switching circuit, the third terminal of the second switching circuit, the controlled terminal of the first switching circuit, and the controlled terminal of the second switching circuit. The controller receives the first sampling signal and the second sampling signal, and controls the conduction state of the first switching circuit and the second switching circuit based on the first sampling signal and the second sampling signal.

2. The detection system according to claim 1, characterized in that, The first switching circuit includes: A voltage source, wherein the voltage source is connected to the second terminal of the second switching circuit, and the voltage source is used to output the reference voltage; and, The first switching module has a first terminal serving as the first terminal of the first switching circuit and connected to the output terminal of the first sampling circuit. The second terminal of the first switching module serves as the second terminal of the first switching circuit and is connected to the voltage source. The third terminal of the first switching module serves as the third terminal of the first switching circuit and is connected to the controller. The controlled terminal of the first switching module serves as the controlled terminal of the first switching circuit and is connected to the controller.

3. The detection system according to claim 2, characterized in that, The first switch module includes a first relay, and the first relay includes: A first coil, one end of which is grounded, and the other end of which serves as the controlled terminal of the first switching module and is connected to the controller; and, The first single-pole double-throw switch has its common terminal serving as the third terminal of the first switch module and connected to the controller. The first switching terminal of the first single-pole double-throw switch serves as the first terminal of the first switch module and is connected to the output terminal of the first sampling circuit. The second switching terminal of the first single-pole double-throw switch serves as the second terminal of the first switch module and is connected to the voltage source.

4. The detection system according to claim 2, characterized in that, The second switching circuit includes: The second switch module has a first terminal that serves as the first terminal of the second switching circuit and is connected to the output terminal of the second sampling circuit. The second terminal of the second switch module serves as the second terminal of the second switching circuit and is connected to the voltage source. The third terminal of the second switch module serves as the third terminal of the second switching circuit and is connected to the controller. The controlled terminal of the second switch module serves as the controlled terminal of the second switching circuit and is connected to the controller.

5. The detection system according to claim 4, characterized in that, The second switch module includes a second relay, and the second relay includes: A second coil, one end of which is grounded, and the other end of which serves as the controlled terminal of the second switching module and is connected to the controller; and, The second single-pole double-throw switch has its common terminal serving as the third terminal of the second switch module and connected to the controller. The first switching terminal of the second single-pole double-throw switch serves as the first terminal of the second switch module and is connected to the output terminal of the second sampling circuit. The second switching terminal of the second single-pole double-throw switch serves as the second terminal of the second switch module and is connected to the voltage source.

6. The detection system according to claim 1, characterized in that, The controller is configured to generate an error signal based on the first sampling signal and the second sampling signal, and when the error signal is greater than or equal to an error threshold, control the second terminal of the first switching circuit to be connected to the third terminal of the first switching circuit, and control the second terminal of the second switching circuit to be connected to the third terminal of the second switching circuit.

7. The detection system according to claim 6, characterized in that, The controller is further configured to generate a first voltage value based on the first sampling signal and a second voltage value based on the second sampling signal, and select one of the first sampling circuit and the second sampling circuit as a main sampling circuit and the other as a sub-sampling circuit based on the first voltage value, the second voltage value and the reference voltage.

8. The detection system according to any one of claims 1-7, characterized in that, The detection system also includes: A first filtering circuit, wherein the first filtering circuit is connected in series between the third terminal of the first switching circuit and the controller; and, The second filter circuit is connected in series between the third terminal of the second switching circuit and the controller.

9. The detection system according to claim 8, characterized in that, The first sampling circuit includes: The first sampling module has its first end connected to the positive terminal of the high-voltage bus as the input terminal of the first sampling circuit. A first filter, wherein a first terminal of the first filter is connected to a second terminal of the first sampling module, and a second terminal of the first filter is connected to the negative terminal of the high-voltage bus; and... A first isolation operational amplifier has its non-inverting input connected to the first terminal of the first filter, its inverting input connected to the second terminal of the first filter, and its output terminal serving as the output terminal of the first sampling circuit, which is connected to the first terminal of the first switching circuit.

10. A vehicle, characterized in that, The vehicles include: The detection system according to any one of claims 1 to 9, wherein the detection system is connected to the high-voltage bus.

Images