Fault detection circuit, bridge inverter circuit, and vehicle

Abstract

This disclosure provides a fault detection circuit, a bridge inverter circuit, and a vehicle. The fault detection circuit includes a detection point for detecting short-circuit faults in the switching elements of the bridge inverter, with detection points disposed between the switching elements. The fault detection circuit is connected between a high-voltage end and a low-voltage end, and includes: a detection voltage acquisition module configured to acquire a detection voltage, the detection voltage acquisition module including a first resistor, a second resistor, and a third resistor, the detection point being connected between the first resistor and the second resistor, wherein the voltage applied to the third resistor is the detection voltage; a reference voltage acquisition module configured to acquire a reference voltage associated with the power supply voltage; and a processing module configured to: receive the detection voltage from the detection voltage acquisition module, receive the reference voltage from the reference voltage acquisition module, and determine whether a short-circuit fault has occurred in one of the switching elements based on a comparison result between the detection voltage and the reference voltage.

Description

Technical Field

[0001] This invention relates to a fault detection circuit, a bridge inverter circuit, and a vehicle. Background Technology

[0002] Driven by environmental and economic considerations, electric vehicles are increasingly being used. Electric vehicles typically use energy-efficient, low-cost AC motors as their drive motors and DC high-voltage batteries as their power batteries. For the drive motor to operate normally, the DC high-voltage electricity from the power battery needs to be converted to AC power. A bridge inverter can be used to perform this DC-AC conversion process. A bridge inverter mainly consists of switching elements. By controlling the on and off states of these switching elements, the direction of the current flowing into the drive motor can be controlled, thereby driving the electric vehicle.

[0003] However, some switching elements in a bridge inverter may experience short-circuit faults. When a bridge inverter, which directly causes short-circuit faults in its switching elements, converts DC power, the short-circuit faults may damage the vehicle's electrical components.

[0004] Therefore, a solution is desired that can detect short-circuit faults in the switching elements before the bridge inverter converts DC power, even if a short-circuit fault occurs in the switching elements. Summary of the Invention

[0005] According to one aspect of the present disclosure, a fault detection circuit is provided for detecting short-circuit faults in switching elements of a bridge arm of a bridge inverter, wherein detection points are provided between the switching elements in the bridge arm, and the fault detection circuit is connected between the high-voltage end and the low-voltage end of the bridge inverter. The fault detection circuit includes: a detection voltage acquisition module configured to acquire a detection voltage, the detection voltage acquisition module including a first resistor, a second resistor, and a third resistor connected in series between the high-voltage end and the low-voltage end, the detection point being connected between the first resistor and the second resistor, wherein the voltage applied to the third resistor is the detection voltage; a reference voltage acquisition module connected between the high-voltage end and the low-voltage end, the reference voltage acquisition module being configured to acquire a reference voltage associated with the power supply voltage; and a processing module configured to: receive the detection voltage from the detection voltage acquisition module, receive the reference voltage from the reference voltage acquisition module, compare the detection voltage with the reference voltage, and determine, based on the comparison result, whether a short-circuit fault has occurred in one of the switching elements.

[0006] For example, in a circuit according to an embodiment of the present disclosure, the reference voltage acquisition module includes a fourth resistor, a fifth resistor, and a sixth resistor connected in series, and wherein the reference voltage is related to the voltage applied to at least one of the fifth resistor and the sixth resistor.

[0007] For example, in a circuit according to an embodiment of the present disclosure, the reference voltage includes a first reference voltage and a second reference voltage, and wherein the processing module obtains a first reference voltage as a voltage applied to a fifth resistor and a sixth resistor from between the fourth resistor and the fifth resistor, and the processing module obtains a second reference voltage as a voltage applied to a sixth resistor from between the fifth resistor and the sixth resistor.

[0008] For example, according to the circuit of an embodiment of the present disclosure, the processing module is configured to: compare the detected voltage with a first reference voltage and a second reference voltage respectively; determine that the switching element has not experienced a short circuit fault in response to the detected voltage being between the first reference voltage and the second reference voltage; determine that a first switching element included in the switching element has experienced a short circuit fault in response to the detected voltage being greater than the first reference voltage; and determine that a second switching element included in the switching element has experienced a short circuit fault in response to the detected voltage being less than the second reference voltage.

[0009] For example, in a circuit according to an embodiment of the present disclosure, the reference voltage acquisition module includes a fourth resistor and a fifth resistor connected in series, and the reference voltage is related to the voltage applied to the fifth resistor.

[0010] For example, according to an embodiment of the present disclosure, the processing module is configured to: obtain a reference voltage as a voltage applied to the fifth resistor from between the fourth and fifth resistors; calculate a power supply voltage based on the reference voltage and the resistance values ​​of the fourth and fifth resistors; and calculate a first voltage threshold and a second voltage threshold based on the power supply voltage, the first and second voltage thresholds being calculated based on: multiplying the power supply voltage by the ratio of the resistance value of the third resistor to the sum of the resistance values ​​of the first, second, and third resistors to obtain a normal voltage; multiplying the power supply voltage by the ratio of the resistance value of the third resistor to the sum of the resistance values ​​of the second and third resistors to obtain a first fault voltage; taking zero as the second fault voltage; determining half of the sum of the normal voltage and the first fault voltage as the first threshold voltage; and determining half of the sum of the normal voltage and the second fault voltage as the second threshold voltage.

[0011] For example, according to the circuit of an embodiment of the present disclosure, the processing module is configured to: compare the detected voltage with a first threshold voltage and a second threshold voltage, respectively; determine that the switching element has not experienced a short circuit fault in response to the detected voltage being between the first threshold voltage and the second threshold voltage; determine that a first switching element included in the switching element has experienced a short circuit fault in response to the detected voltage being greater than the first threshold voltage; and determine that a second switching element included in the switching element has experienced a short circuit fault in response to the detected voltage being less than the second threshold voltage.

[0012] For example, in a method according to an embodiment of the present disclosure, the switching element includes one or more of a mechanical switch, an insulated gate bipolar transistor, a metal-oxide-semiconductor field-effect transistor, a silicon carbide transistor, and a gallium nitride transistor.

[0013] According to one aspect of the present disclosure, a bridge inverter circuit is provided, including: one or more bridge arms, and a fault detection circuit as described above, which will not be repeated here for the sake of brevity.

[0014] According to one aspect of the present disclosure, a vehicle is provided, including the fault detection circuit as described above or the bridge inverter circuit as described above, which will not be repeated here for the sake of brevity.

[0015] The fault detection circuit, bridge inverter circuit, and vehicle according to embodiments of the present disclosure provide a scheme to detect potential short-circuit faults in switching elements before the bridge inverter converts DC power, thereby preventing wider damage to circuit components due to short-circuit faults. The fault detection circuit according to the present disclosure is low in complexity, easy to implement, and has low hardware cost. Attached Figure Description

[0016] The above and other aspects, features, and advantages of specific embodiments of the present disclosure will become clearer from the following description taken in conjunction with the accompanying drawings, in which:

[0017] Figure 1 This is a schematic diagram of a bridge inverter circuit according to an embodiment of the present disclosure.

[0018] Figure 2 This is a schematic diagram of a fault detection circuit according to an embodiment of the present disclosure.

[0019] Figure 3 This is a schematic diagram of a fault detection circuit according to an embodiment of the present disclosure.

[0020] Figure 4 This is a schematic diagram of a fault detection circuit according to an embodiment of the present disclosure.

[0021] Figure 5This is a schematic diagram of a vehicle according to an embodiment of the present disclosure. Detailed Implementation

[0022] Before proceeding with the detailed description below, it may be advantageous to define certain words and phrases used throughout this disclosure. The terms “comprising” and “including” and their derivatives mean, but are not limited to, “including”. The phrase “at least one”, when used with a list of items, means that different combinations of one or more of the listed items may be used, and that only one item in the list may be required. For example, “at least one of A, B, and C” includes any one of the following combinations: A, B, C, A and B, A and C, B and C, A and B and C.

[0023] Definitions of other specific words and phrases are provided throughout this disclosure. Those skilled in the art will understand that, in many, if not most, cases, such definitions apply to the prior and future use of the words and phrases thus defined.

[0024] The various embodiments of the principles of this disclosure described below in conjunction with the accompanying drawings are for illustrative purposes only and should not be construed as limiting the scope of this disclosure in any way. Those skilled in the art will understand that the principles of this disclosure can be implemented in any suitably arranged system or device. In some cases, the actions described in this disclosure may be performed in a different order and still achieve the desired result. Furthermore, the processes depicted in the drawings do not necessarily require a specific order or sequential sequence to achieve the desired result. In certain embodiments, multitasking and parallel processing may be advantageous.

[0025] The text and accompanying drawings are provided by way of example only to aid in understanding this disclosure. They should not be construed as limiting the scope of the claims appended to this disclosure in any way. Throughout the drawings, the same reference numerals generally indicate the same elements. Although certain embodiments and examples have been provided, it will be apparent to those skilled in the art, based on the content of this disclosure, that changes may be made to the illustrated embodiments and examples without departing from the scope of this disclosure.

[0026] Figure 1 This is a schematic diagram of a bridge inverter circuit according to an embodiment of the present disclosure. The bridge inverter circuit 100 may include switching elements 111, 112, 121, 122, 131, 132 and a power supply 140.

[0027] like Figure 1As shown, switching elements 111 and 112 can form the first bridge arm 110, switching elements 121 and 122 can form the second bridge arm 120, and switching elements 131 and 132 can form the third bridge arm 130. By controlling the switching elements 111 to 132 to be turned on and off using control signals 1-6 respectively, the DC power supplied by the power supply 140 can be converted into three-phase AC power. According to an embodiment of this disclosure, by controlling the switching elements 111 and 112 included in the first bridge arm 110 to be turned on and off using control signals 1-2, U-phase voltage can be provided to the drive motor via the U-phase output terminal. By controlling the switching elements 121 and 122 included in the second bridge arm 120 to be turned on and off using control signals 3-4, V-phase voltage can be provided to the drive motor via the V-phase output terminal. By controlling the switching elements 131 and 132 included in the third bridge arm 130 to be turned on and off using control signals 5-6, W-phase voltage can be provided to the drive motor via the W-phase output terminal. By supplying the drive motor with three-phase AC voltage, including U-phase voltage, V-phase voltage, and W-phase voltage, the drive motor can drive the electric vehicle.

[0028] Figure 1 Switching elements 111-132 are shown in the form of insulated gate bipolar transistors (IGBTs), but switching elements 111-132 may also include one or more of mechanical switches, metal-oxide-semiconductor field-effect transistors (MOSFETs), silicon carbide (SiC) transistors, and gallium nitride (GaN) transistors.

[0029] Figure 1 One of the switching elements 111-132 in the bridge (e.g., a switching element in one of the first bridge arm 110, the second bridge arm 120, and the third bridge arm 130) may experience a short-circuit fault. If the bridge inverter circuit 100 with the short-circuited switching element is switched to DC power, a wider range of circuit elements may be damaged due to the short-circuit fault.

[0030] Figure 2 This is a schematic diagram of a fault detection circuit according to an embodiment of the present disclosure. Figure 2 An example of using a fault detection circuit to detect a short-circuit fault in a switching element in the first arm 110 of a bridge inverter circuit 100 is shown, but those skilled in the art will understand that a fault detection circuit can be used to detect short-circuit faults in switching elements in one or more of the second arm 120 and the third arm 130 of the bridge inverter circuit 100.

[0031] like Figure 2As shown, the fault detection circuit 200 can be connected between the high-voltage and low-voltage ends of the bridge inverter. The fault detection circuit 200 may include a detection voltage acquisition module 210, a reference voltage acquisition module 220, and a processing module 230.

[0032] A detection point 240 can be provided between the switching elements 111 and 112 in the bridge arm to detect short-circuit faults of the aforementioned switching elements.

[0033] The detection voltage acquisition module 210 can be configured to acquire a detection voltage. The detection voltage acquisition module 210 may include a first resistor R1, a second resistor R2, and a third resistor R3 connected in series between the high-voltage end and the low-voltage end. Figure 2 As shown, detection point 240 can be connected between the first resistor R1 and the second resistor R2. The voltage applied to the third resistor R3 can be the detection voltage. The detection voltage acquisition module 210 can send the detection voltage to the processing module 230, for example, through the detection voltage input terminal of the processing module 230. Figure 1 (Not shown) can be connected between the second resistor R2 and the third resistor R3 in the detection voltage acquisition module 210. Although not shown, those skilled in the art will understand that the detection voltage acquisition module 210 can be connected to the processing module 230 via an amplifier to amplify the detection voltage. The detection voltage output by the detection voltage acquisition module 210 may vary depending on whether one of the switching elements 111 and 112 in the detected bridge arm is faulty and which of the switching elements 111 and 112 is faulty.

[0034] The reference voltage acquisition module 220 can be connected between the high-voltage end and the low-voltage end. The reference voltage acquisition module 220 can be configured to acquire a reference voltage associated with the power supply voltage of the power supply 140. The reference voltage acquisition module 220 can send the reference voltage to the processing module 230, for example, through the reference voltage input terminal of the processing module 230. Figure 1(Not shown) can be connected to the reference voltage acquisition module 220. Although not shown, those skilled in the art will understand that the reference voltage acquisition module 220 can be connected to the processing module 230 via an amplifier to amplify the reference voltage. Regardless of whether one of the switching elements 111 and 112 in the detected bridge arm is faulty, and which of the switching elements 111 and 112 is faulty, the reference voltage output by the reference voltage acquisition module 220 can remain unchanged. By comparing the detected voltage with the reference voltage, the processing module 230 can determine whether one of the switching elements 111 and 112 has a short-circuit fault based on the comparison result. According to one embodiment of this disclosure, whether one of the switching elements 111 and 112 has a short-circuit fault, and which switching element has a short-circuit fault, can be determined based on the magnitude relationship between the detected voltage and the reference voltage.

[0035] Processing module 230 can be configured to receive a detected voltage from detection voltage acquisition module 210 and a reference voltage from reference voltage acquisition module 220. Although Figure 2 Although not shown, the fault detection circuit may further include one or more memories storing one or more computer program modules. One or more computer program modules may be configured to be read and executed by the processing module 230. These computer program modules include methods for performing a method according to at least one embodiment of the present disclosure for comparing a reference voltage and a detection voltage to determine a short-circuit fault in a switching element. When executed by the processing module 230, these methods can perform the steps of the method according to at least one embodiment of the present disclosure for comparing a reference voltage and a detection voltage to determine a short-circuit fault in a switching element.

[0036] The memory and processing module 230 can be interconnected via a bus system and / or other forms of connection mechanism (not shown). For example, the bus can be a Peripheral Component Interconnect Standard (PCI) bus or an Extended Industry Standard Architecture (EISA) bus. The communication bus can be divided into an address bus, a data bus, a control bus, etc.

[0037] For example, the processing module 230 may be a microcontroller unit (MCU), a central processing unit (CPU), a digital signal processor (DSP), a graphics processing unit (GPU), or other forms of processing unit with data processing capabilities and / or program execution capabilities, such as a field-programmable gate array (FPGA). The processing module 230 may be a general-purpose processor or a special-purpose processor, and may control other components in the fault detection circuit 200 to perform the desired functions.

[0038] Exemplarily, the memory may include any combination of one or more computer program products, which may include various forms of computer-readable storage media, such as volatile memory and / or non-volatile memory. Volatile memory may include, for example, random access memory (RAM) and / or cache. Non-volatile memory may include, for example, read-only memory (ROM), hard disk, erasable programmable read-only memory (EPROM), portable compact disc read-only memory (CD-ROM), USB storage, flash memory, etc. One or more computer program modules may be stored on the computer-readable storage medium, and the processing module 230 may run one or more computer program modules to implement the various functions described above. Various applications and various data, as well as various data used and / or generated by the applications, may also be stored in the computer-readable storage medium.

[0039] Figure 3 This is a schematic diagram of a fault detection circuit according to an embodiment of the present disclosure. Figure 3 Zhongyu Figure 2 The same components will not be described again.

[0040] The fault detection circuit 300 can be connected between the high-voltage and low-voltage sides of the bridge inverter. The fault detection circuit 200 may include a detection voltage acquisition module 210, a reference voltage acquisition module 220, and a processing module 230.

[0041] like Figure 3 As shown, the reference voltage acquisition module 220 may include a fourth resistor R4, a fifth resistor R5, and a sixth resistor R6 connected in series between the high-voltage end and the low-voltage end. The reference voltage may be related to the voltage applied to at least one of the fifth resistor R5 and the sixth resistor R6.

[0042] According to one embodiment of this disclosure, the reference voltage may include a first reference voltage V. REF_1 Second reference voltage V REF_2 First reference voltage V REF_1 This can correspond to the high reference voltage, the second reference voltage V. REF_2 This can correspond to a low reference voltage. Processing module 230 can obtain a first reference voltage V, which serves as the voltage applied to the fifth resistor R5 and the sixth resistor R6, from between the fourth resistor R4 and the fifth resistor R5. REF_1 The processing module 230 can obtain a second reference voltage V, which serves as the voltage applied to the sixth resistor R6, from between the fifth resistor R5 and the sixth resistor R6. REF_2 Specifically, the first reference voltage V can be obtained through the following equation (1). REF_1 :

[0043] (1)

[0044] Among them, V power R1 is the power supply voltage of power supply 140V, and R4, R5, and R6 are the resistance values ​​of the fourth resistor R4, the fifth resistor R5, and the sixth resistor R6, respectively.

[0045] The second reference voltage V can be obtained through the following equation (2). REF_2 :

[0046] (2)

[0047] As described above, regardless of whether one of the switching elements 111 and 112 in the detected bridge arm is faulty, and which of the switching elements 111 and 112 is faulty, the first reference voltage V output by the reference voltage acquisition module 220... REF_1 and the second reference voltage V REF_2 It can remain unchanged.

[0048] If neither switching element 111 nor switching element 112 experiences a short circuit fault, the detection voltage obtained by processing module 230 from the second resistor R2 and the third resistor R3 included in detection voltage acquisition module 210 can be obtained by the following equation (3):

[0049] (3)

[0050] Where r1, r2, and r3 are the resistance values ​​of the first resistor R1, the second resistor R2, and the third resistor R3, respectively.

[0051] In the case where a short circuit fault occurs in switching element 111 and a short circuit fault does not occur in switching element 112, the detection voltage obtained by processing module 230 can be obtained by the following equation (4):

[0052] (4)

[0053] In the case where a short circuit fault occurs in switching element 112 and no short circuit fault occurs in switching element 111, the detection voltage obtained by processing module 230 can be obtained by the following equation (5):

[0054] (5)

[0055] Based on the above equations (3)-(5), the magnitude relationships between the detection voltage Vc1 indicating that neither of the two switching elements in a bridge arm has a short-circuit fault, the detection voltage Vc2 indicating that the upper switching element (e.g., the switching element 111 near the high-voltage end) and the lower switching element (e.g., the switching element 112 near the low-voltage end) in the bridge arm have a short-circuit fault, and the detection voltage Vc3 indicating that the lower switching element (e.g., the switching element 112 near the low-voltage end) and the upper switching element (e.g., the switching element 111 near the high-voltage end) in the bridge arm have a short-circuit fault, are as follows: The magnitude relationships between Vc1, Vc2, and Vc3 are shown in the following equation (6):

[0056] (6)

[0057] By properly configuring the resistance values ​​of the fourth resistor R4, the fifth resistor R5, and the sixth resistor R6 included in the reference voltage acquisition module 220, it is possible to make Vc1, Vc2, and Vc3 correlate with the first reference voltage Vc1. REF_1 and the second reference voltage V REF_2 The following equations (7)-(9) can exist to show the size relationship:

[0058] (7)

[0059] (8)

[0060] (9)

[0061] In other words, the processing module 230 can be configured to: compare the detected voltage detected by the detection voltage acquisition module 210 (e.g., in real time) with the first reference voltage V. REF_1 and the second reference voltage V REF_2 A comparison is made. In response to the detected voltage being between the first reference voltage and the second reference voltage, the processing module 230 can determine that no short-circuit fault has occurred in the switching element of that bridge arm. In response to the detected voltage being greater than the first reference voltage V... REF_1 The processing module 230 can determine that a short-circuit fault has occurred in one of the switching elements (e.g., switching element 111 near the high-voltage end). This is in response to a detection voltage less than the second reference voltage V. REF_2 The processing module 230 can handle a short-circuit fault in another switching element included in the switching elements (e.g., switching element 112 near the low-voltage end).

[0062] Figure 4 This is a schematic diagram of a fault detection circuit according to an embodiment of the present disclosure. Figure 3 Zhongyu Figure 2 The same components will not be described again.

[0063] The fault detection circuit 400 can be connected between the high-voltage and low-voltage sides of the bridge inverter. The fault detection circuit 200 may include a detection voltage acquisition module 210, a reference voltage acquisition module 220, and a processing module 230.

[0064] like Figure 4 As shown, the reference voltage acquisition module 220 may include a seventh resistor R7 and an eighth resistor R8 connected in series between the high-voltage end and the low-voltage end. The reference voltage may be related to the voltage applied to the eighth resistor R8.

[0065] Processing module 230 can be configured to obtain a reference voltage between the seventh resistor R7 and the eighth resistor R8 as the voltage applied to the eighth resistor R8, and calculate the power supply voltage based on the pre-configured resistance values ​​of the seventh resistor R7 and the eighth resistor R8 and the reference voltage. Specifically, processing module 230 can calculate the power supply voltage based on the following equation (10):

[0066] (10)

[0067] Among them, V power It is the calculated power supply voltage, V REF This is the reference voltage obtained by processing module 230 from between the seventh resistor R7 and the eighth resistor R8, where r7 and r8 are the resistance values ​​of the seventh resistor R7 and the eighth resistor R8, respectively. By connecting the seventh resistor R7 and the eighth resistor R8 in series, the reference voltage obtained by processing module 230 can be reduced. For example, processing module 230 obtains the voltage division of the eighth resistor R8 as the reference voltage instead of directly obtaining the power supply voltage, thereby protecting processing module 230 from high voltage damage.

[0068] Based on power supply voltage V power In addition to the pre-configured resistance values ​​of the first resistor R1 and the third resistor R3, the processing module 230 can calculate, as shown in equations (3) to (5), the detection voltage Vc1 indicating that neither of the two switching elements in a bridge arm has a short circuit fault, the detection voltage Vc2 indicating that the upper switching element (e.g., the switching element 111 near the high voltage end) and the lower switching element (e.g., the switching element 112 near the low voltage end) in the two switching elements in the bridge arm have a short circuit fault, and the detection voltage Vc3 indicating that the lower switching element (e.g., the switching element 112 near the low voltage end) and the upper switching element (e.g., the switching element 111 near the high voltage end) in the two switching elements in the bridge arm have a short circuit fault, and the upper switching element (e.g., the switching element 111 near the high voltage end) has a short circuit fault.

[0069] According to one embodiment of this disclosure, the processing module 230 can compare the detection voltage detected by the detection voltage acquisition module 210 (e.g., in real time) with the detection voltages Vc1, Vc2, and Vc3 to determine whether a short-circuit fault has occurred in a switching element in the bridge arm and which switching element has experienced a short-circuit fault.

[0070] According to another embodiment of this disclosure, the processing module 230 may be further configured to calculate a first voltage threshold and a second voltage threshold.

[0071] Processing module 230 can determine the first voltage threshold according to the following equation (11):

[0072] (11)

[0073] Processing module 230 can determine the second voltage threshold according to the following equation (12):

[0074] (12)

[0075] In other words, the processing module 230 can determine half of the sum of the detection voltage Vc1, which indicates that the switching element in the indicator bridge arm has not experienced a short circuit fault, and the detection voltage Vc2, which indicates that the switching element 111 near the high-voltage end in the indicator bridge arm has experienced a short circuit fault, as the first threshold voltage, and determine half of the sum of the detection voltage Vc1, which is the normal voltage, and the detection voltage Vc3, which indicates that the switching element 112 near the low-voltage end in the indicator bridge arm has experienced a short circuit fault, as the second threshold voltage.

[0076] The processing module 230 can compare the detected voltage detected by the detection voltage acquisition module 210 (e.g., in real time) with a first threshold voltage and a second threshold voltage, respectively. In response to the detected voltage being between the first and second threshold voltages, the processing module 230 can determine that none of the switching elements included in the bridge arm have experienced a short-circuit fault. In response to the detected voltage being greater than the first threshold voltage, the processing module 230 can determine that a short-circuit fault has occurred in the switching element near the high-voltage end of the bridge arm. In response to the detected voltage being less than the second threshold voltage, the processing module 230 can determine that a short-circuit fault has occurred in the switching element near the low-voltage end of the bridge arm. This hysteretic approach improves the robustness of the fault detection circuit's detection results and avoids false alarms.

[0077] Figure 3 and Figure 4The fault detection circuit shown has the advantage of obtaining a more accurate reference voltage compared to the processing module 230, which directly determines the reference voltage based on the rated power supply voltage. This is because the output voltage of a power supply (e.g., a battery) may fluctuate greatly under different conditions (high current discharge, low current discharge, different states of charge, etc.), so the reference voltage obtained in real time by the reference voltage acquisition module 220 can be more accurate.

[0078] although Figures 2-4 Each of resistors R1-R8 is shown as a single resistor, but those skilled in the art will understand that one or more of resistors R1-R8 can be formed by connecting multiple resistors in series for purposes such as voltage division.

[0079] According to one aspect of the embodiments of this disclosure, a method such as Figure 1 The bridge inverter circuit shown includes one or more bridge arms, and at least one of the bridge arms is configured as follows: Figures 2-4 The fault detection circuit shown here will not be described in detail for the sake of simplicity.

[0080] Figure 5 This is a schematic diagram of a vehicle according to an embodiment of the present disclosure.

[0081] Vehicle 500 may include, but is not limited to, cars, tractor-trailers (with or without trailers), buses, recreational vehicles, minivans, or sport utility vehicles (SUVs).

[0082] like Figure 5 As shown, vehicle 500 may include device 510, which may be the fault detection circuit 200-400 described above or the bridge inverter circuit described above.

[0083] The fault detection circuit, bridge inverter circuit, and vehicle according to embodiments of the present disclosure provide a scheme to detect potential short-circuit faults in switching elements before the bridge inverter converts DC power, thereby preventing wider damage to circuit components due to short-circuit faults. The fault detection circuit according to the present disclosure is low in complexity, easy to implement, and has low hardware cost.

[0084] Although this disclosure has been described with reference to exemplary embodiments, various changes and modifications may be suggested to those skilled in the art. This disclosure is intended to cover such changes and modifications that fall within the scope of the appended claims.

[0085] Any description in this invention should not be construed as implying that any particular element, step, or function is an essential element that must be included within the scope of the claims. The scope of the patent subject matter is defined only by the claims.

Claims

1. A fault detection circuit for detecting a short-circuit fault of a switching element in a bridge arm of a bridge inverter, detection points being provided between the switching elements in the bridge arm, the fault detection circuit being connected between a high voltage terminal and a low voltage terminal of the bridge inverter, wherein, The fault detection circuit includes: A detection voltage acquisition module is configured to acquire a detection voltage. The detection voltage acquisition module includes a first resistor, a second resistor, and a third resistor connected in series between the high voltage end and the low voltage end. The detection point is connected between the first resistor and the second resistor, wherein the voltage applied to the third resistor is the detection voltage. A reference voltage acquisition module, connected between the high-voltage terminal and the low-voltage terminal, configured to acquire a reference voltage associated with the power supply voltage; and The processing module is configured to: Receive the detection voltage from the detection voltage acquisition module. Receive the reference voltage from the reference voltage acquisition module. The detected voltage is compared with the reference voltage, and Based on the comparison results, determine whether a short-circuit fault has occurred in one of the switching elements.

2. The circuit according to claim 1, wherein, The reference voltage acquisition module includes a fourth resistor, a fifth resistor, and a sixth resistor connected in series. The reference voltage is related to the voltage applied to at least one of the fifth and sixth resistors.

3. The circuit according to claim 2, wherein, The reference voltage includes a first reference voltage and a second reference voltage, and wherein, The processing module obtains a first reference voltage from between the fourth and fifth resistors as the voltage applied to the fifth and sixth resistors. The processing module obtains a second reference voltage between the fifth and sixth resistors as the voltage applied to the sixth resistor.

4. The circuit according to claim 3, wherein the processing module is configured as follows: The detected voltage is compared with the first reference voltage and the second reference voltage, respectively; In response to the detected voltage being between the first reference voltage and the second reference voltage, it is determined that the switching element has not experienced a short-circuit fault. In response to the detection voltage being greater than the first reference voltage, a short-circuit fault occurs in the first switching element included in the switching element; as well as In response to the detection voltage being less than the second reference voltage, a short-circuit fault occurs in the second switching element included in the switching element.

5. The circuit according to claim 1, wherein, The reference voltage acquisition module includes a fourth resistor and a fifth resistor connected in series, and The reference voltage is related to the voltage applied to the fifth resistor.

6. The circuit according to claim 5, wherein, The processing module is configured as follows: A reference voltage is obtained between the fourth and fifth resistors as the voltage applied to the fifth resistor. The power supply voltage is calculated based on the reference voltage and the resistance values ​​of the fourth and fifth resistors. The first voltage threshold and the second voltage threshold are calculated based on the power supply voltage. The first voltage threshold and the second voltage threshold are calculated based on the following: Multiply the power supply voltage by the ratio of the resistance value of the third resistor to the sum of the resistance values ​​of the first, second, and third resistors to obtain the normal voltage. The first fault voltage is obtained by multiplying the power supply voltage by the ratio of the resistance value of the third resistor to the sum of the resistance values ​​of the second and third resistors. Use zero as the second fault voltage. Half of the sum of the normal voltage and the first fault voltage is defined as the first threshold voltage. Half of the sum of the normal voltage and the second fault voltage is determined as the second threshold voltage.

7. The circuit according to claim 6, wherein the processing module is configured as follows: The detected voltage is compared with the first threshold voltage and the second threshold voltage, respectively; In response to the detected voltage being between the first threshold voltage and the second threshold voltage, it is determined that the switching element has not experienced a short-circuit fault. In response to the detection voltage being greater than the first threshold voltage, a short-circuit fault occurs in the first switching element included in the switching element; as well as In response to the detection voltage being less than the second threshold voltage, a short-circuit fault occurs in the second switching element included in the switching element.

8. The method according to claim 1, wherein, The switching element includes one or more of the following: mechanical switch, insulated gate bipolar transistor, metal-oxide-semiconductor field-effect transistor, silicon carbide transistor, and gallium nitride transistor.

9. A bridge inverter circuit, comprising: One or more bridge arms, The fault detection circuit as described in any one of claims 1-8.

10. A vehicle comprising a fault detection circuit as described in any one of 1-8 or a bridge inverter circuit as described in claim 9.

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