Fault detection circuit, bridge inverter circuit and vehicle

Abstract

The present disclosure provides a fault detection circuit, a bridge inverter circuit, and a vehicle. The fault detection circuit is used for detecting a short-circuit fault in switching elements of a bridge inverter, with a detection point provided between the switching elements. The fault detection circuit is connected between a high-voltage end and a low-voltage end, and comprises: a detection voltage acquisition module configured to acquire a detection voltage, the detection voltage acquisition module comprising a first resistor, a second resistor, and a third resistor, the detection point being connected between the first resistor and the second resistor, wherein a voltage applied to the third resistor is the detection voltage; a reference voltage acquisition module configured to acquire a reference voltage associated with a 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, on the basis of a comparison result between the detection voltage and the reference voltage, whether a short-circuit fault has occurred in one of the switching elements.

Description

[0001] Description

[0002] FAULT DETECTION CIRCUIT, BRIDGE INVERTER CIRCUIT AND VEHICLE

[0003] Technical Field

[0004] The present invention relates to a fault detection circuit, a bridge inverter circuit, and a vehicle.

[0005] Background Art

[0006] Due to environmental and economic considerations, electric vehicles are increasingly being used. Electric vehicles typically use energy-efficient, low-cost AC electric motors as their drive motors and DC high-voltage batteries as their power batteries. To cause the drive motor to operate normally, DC high-voltage power from the power battery needs to be converted to AC power. The process of DC / AC conversion of electric energy can be completed using a bridge inverter. The bridge inverter mainly consists of switching elements. By controlling the switching elements to turn on and off, the direction of a current flowing into the drive motor can be controlled, thereby driving the electric vehicle.

[0007] However, short-circuit faults may occur in some switching elements in the bridge inverter. When a bridge inverter directly causing a short-circuit fault to occur in the switching elements converts DC power, the short-circuit fault may damage the vehicle's circuit components.

[0008] Therefore, a solution is desired that can detect a short-circuit fault in the switching elements before the bridge inverter causing the short-circuit fault to occur in the switching elements converts DC power.

[0009] Summary

[0010] According to one aspect of the embodiments of the present disclosure, there is provided a fault detection circuit, used for detecting a short-circuit fault in switching elements of a bridge arm of a bridge inverter, with a detection point provided ibetween the switching elements in the bridge arm, the fault detection circuit being connected between a high-voltage end and a low- voltage end of the bridge inverter, wherein the fault detection circuit comprises: a detection voltage acquisition module configured to acquire a detection voltage, the detection voltage acquisition module comprising a first resistor, a second resistor, and a third resistor connected in series between the high-voltage end and the low- voltage end, and the detection point being connected between the first resistor and the second resistor, wherein a 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 a 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, on the basis of a comparison result, whether a short-circuit fault has occurred in one of the switching elements.

[0011] For example, in the circuit according to an embodiment of the present disclosure, the reference voltage acquisition module comprises a fourth resistor, a fifth resistor, and a sixth resistor connected in series, and wherein the reference voltage is related to a voltage applied to at least one of the fifth resistor and the sixth resistor.

[0012] For example, in the circuit according to an embodiment of the present disclosure, the reference voltage comprises a first reference voltage and a second reference voltage, and wherein the processing module obtains the first reference voltage from between the fourth resistor and the fifth resistor as a voltage applied to the fifth resistor and the sixth resistor, and the processing module obtains the second reference voltage from between the fifth resistor and the sixth resistor as a voltage applied to the sixth resistor.

[0013] For example, in the circuit according to an embodiment of the present disclosure, the processing module is configured to: compare the detection voltage with the first reference voltage and the second reference voltage separately; inresponse to the detection voltage being between the first reference voltage and the second reference voltage, determine that no short-circuit fault has occurred in the switching elements; in response to the detection voltage being greater than the first reference voltage, determine that a short-circuit fault has occurred in a first switching element included in the switching elements; and in response to the detection voltage being less than the second reference voltage, determine that a short-circuit fault has occurred in a second switching element included in the switching elements.

[0014] For example, in the circuit according to an embodiment of the present disclosure, the reference voltage acquisition module comprises a fourth resistor and a fifth resistor connected in series, and wherein the reference voltage is related to a voltage applied to the fifth resistor.

[0015] For example, in the circuit according to an embodiment of the present disclosure, the processing module is configured to: obtain a reference voltage from between the fourth resistor and the fifth resistor as a voltage applied to the fifth resistor, calculate a power supply voltage on the basis of the reference voltage and resistance values of the fourth resistor and the fifth resistor, and calculate a first threshold voltage and a second threshold voltage on the basis of the power supply voltage, and the first threshold voltage and the second threshold voltage are calculated on the basis of the following: the power supply voltage is multiplied by a ratio of a resistance value of the third resistor to a sum of resistance values of the first resistor, the second resistor and the third resistor to obtain a normal voltage, the power supply voltage is multiplied by a ratio of the resistance value of the third resistor to a sum of the resistance values of the second resistor and the third resistor to obtain a first fault voltage, zero is used as a second fault voltage, half of a sum of the normal voltage and the first fault voltage is determined as the first threshold voltage, and half of a sum of the normal voltage and the second fault voltage is determined as the second threshold voltage.

[0016] For example, in the circuit according to an embodiment of the present disclosure, the processing module is configured to: compare the detection voltage with the first threshold voltage and the second threshold voltage separately; inresponse to the detection voltage being between the first threshold voltage and the second threshold voltage, determine that no short-circuit fault has occurred in the switching elements; in response to the detection voltage being greater than the first threshold voltage, determine that a short-circuit fault has occurred in a first switching element included in the switching elements; and in response to the detection voltage being less than the second threshold voltage, determine that a short-circuit fault has occurred in a second switching element included in the switching elements.

[0017] For example, in the circuit according to an embodiment of the present disclosure, the switching elements comprise 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.

[0018] According to one aspect of the present disclosure, there is provided a bridge inverter circuit, comprising: one or more bridge arms, and a fault detection circuit as described above, which will not be repeated here for the sake of brevity.

[0019] According to one aspect of the present disclosure, there is provided a vehicle, comprising 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.

[0020] The fault detection circuit, bridge inverter circuit, and vehicle according to the embodiments of the present disclosure provide a solution that can detect potential short-circuit faults in the switching elements before the bridge inverter converts DC power, thereby preventing more extensive damage to circuit components due to the short-circuit faults. The fault detection circuit according to the present disclosure is low in complexity, easy to implement, and has low hardware cost.

[0021] Brief Description of the Drawings

[0022] The above description of specific embodiments and other aspects, features and advantages of the present disclosure will become clearer from the following description in conjunction with the drawings, wherein:

[0023] Fig. 1 is a schematic diagram of a bridge inverter circuit according to an embodiment of the present disclosure.Fig. 2 is a schematic diagram of a fault detection circuit according to an embodiment of the present disclosure.

[0024] Fig. 3 is a schematic diagram of a fault detection circuit according to an embodiment of the present disclosure.

[0025] Fig. 4 is a schematic diagram of a fault detection circuit according to an embodiment of the present disclosure.

[0026] Fig. 5 is a schematic diagram of a vehicle according to an embodiment of the present disclosure.

[0027] Detailed Description of the Embodiments

[0028] It may be advantageous to set forth definitions of certain words and phrases used throughout the present disclosure before providing the detailed description below. The terms “comprise” and “include” and derivatives thereof mean including but not limited to. 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 only one item from the list may be required. For example, “at least one of A, B and C” includes any of the following combinations: A, B, C, A and B, A and C, B and C, or A and B and C.

[0029] Definitions for other specific words and phrases are provided throughout the present disclosure. A person skilled in the art will understand that, in many situations, if not most situations, these definitions also apply to past and future uses of the words and phrases so defined.

[0030] The various embodiments below that describe the principles of the present disclosure in this patent document in conjunction with the drawings merely serve as illustration, and should not be construed as limiting the scope of the present disclosure in any way. A person skilled in the art will understand that the principles of the present disclosure can be implemented in any suitably arranged system or device. In certain situations, actions described in the present disclosure can be executed in a different order, and the desired result can still be achieved. In addition, the processes depicted in the drawings do not necessarily need to follow the specific order or sequential order shown to achieve the desired result. In specificembodiments, multitask and parallel processing may be advantageous.

[0031] The present text and drawings are only provided for exemplary purposes, to help understand the present disclosure. They should not be construed as limiting the scope of the claims of the present disclosure in any way. Throughout the drawings, the same reference signs normally refer to the same elements. Although certain embodiments and examples have been provided, it is clear to a person skilled in the art that without departing from the scope of the present disclosure, on the basis of the content of the present disclosure, changes could be made to the shown embodiments and examples.

[0032] Fig. 1 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 and 132 and a power supply 140.

[0033] As shown in Fig. 1, the switching elements 111 and 112 may form a first bridge arm 110, the switching elements 121 and 122 may form a second bridge arm 120, and the switching elements 131 and 132 may form a third bridge arm 130. By controlling the switching elements 111 to 132 to turn on and off using control signals 1 to 6 respectively, DC power supplied by power supply 140 can be converted into three-phase AC power. According to an embodiment of the present disclosure, by controlling the switching elements 111 and 112 included in the first bridge arm 110 to turn on and off using control signals 1 and 2, a U-phase voltage can be supplied to a drive motor via a U-phase output terminal. By controlling the switching elements 121 and 122 included in the second bridge arm 120 to turn on and off using control signals 3 and 4, a V-phase voltage can be supplied to the drive motor via a V-phase output terminal. By controlling the switching elements 131 and 132 included in the third bridge arm 130 to turn on and off using control signals 5 and 6, a W-phase voltage can be supplied to the drive motor via a W-phase output terminal. By supplying AC power with a three-phase voltage including the U-phase voltage, the V-phase voltage, and the W-phase voltage to the drive motor, the drive motor can drive the electric vehicle.

[0034] Fig. 1 shows the switching elements 111 to 132 in the form of insulated gate bipolar transistors (IGBTs), but the switching elements 111 to 132 may furtherinclude one or more of a mechanical switch, a metal-oxide- semiconductor fieldeffect transistor (MOSFET), a silicon carbide (SiC) transistor, and a gallium nitride (GaN) transistor.

[0035] A short-circuit fault may occur in one of the switching elements 111 to 132 in Fig. 1 (e.g., a switching element in one of the first bridge arm 110, the second bridge arm 120, and the third bridge arm 130). If the bridge inverter circuit 100 in which a switching element has a short-circuit fault converts the DC power, more extensive damage to circuit components may be caused due to the short-circuit fault.

[0036] Fig. 2 is a schematic diagram of a fault detection circuit according to an embodiment of the present disclosure. Fig. 2 shows an example of using the fault detection circuit to detect a short-circuit fault in a switching element in the first bridge arm 110 of the bridge inverter circuit 100, but it can be understood by those skilled in the art that the fault detection circuit can be used to detect short-circuit faults in switching elements in one or more of the second bridge arm 120 and the third bridge arm 130 of the bridge inverter circuit 100.

[0037] As shown in Fig. 2, the fault detection circuit 200 may be connected between the high-voltage end and the low-voltage end 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.

[0038] A detection point 240 may be provided between the switching elements 111 and 112 in the bridge arm to detect short-circuit faults in the above switching elements.

[0039] The detection voltage acquisition module 210 may be configured to acquire a detection voltage. The detection voltage acquisition module 210 may include a first resistor Rl, a second resistor R2, and a third resistor R3 connected in series between the high-voltage end and the low-voltage end. As shown in Fig. 2, the detection point 240 may be connected between the first resistor Rl and the second resistor R2. A voltage applied to the third resistor R3 may be the detection voltage. The detection voltage acquisition module 210 may send the detection voltage to the processing module 230. For example, a detection voltage input end (not shown in Fig. 1) of the processing module 230 may be connected between the second resistor R2 and thethird resistor R3 in the detection voltage acquisition module 210. Although not shown, it can be understood by those skilled in the art that the detection voltage acquisition module 210 may 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 a faulty switching element.

[0040] The reference voltage acquisition module 220 may be connected between the high-voltage end and the low-voltage end, and the reference voltage acquisition module 220 may be configured to acquire a reference voltage associated with the power supply voltage of power supply 140. The reference voltage acquisition module 220 may send the reference voltage to the processing module 230. For example, the reference voltage input end of the processing module 230 (not shown in Fig. 1) may be connected to the reference voltage acquisition module 220. Although not shown, it can be understood by those skilled in the art that the reference voltage acquisition module 220 may be connected to the processing module 230 via an amplifier to amplify the reference voltage. The reference voltage output by the reference voltage acquisition module 220 may remain unchanged 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 a faulty switching element. By comparing the detection voltage with the reference voltage, the processing module 230 can determine, on the basis of the comparison result, whether a short-circuit fault has occurred in one of the switching elements 111 and 112. According to an embodiment of the present disclosure, it is possible to determine, on the basis of the relationship between the detection voltage and the reference voltage, whether a short-circuit fault has occurred in one of the switching elements 111 and 112, and which of the switching elements is a switching element with a short-circuit fault.

[0041] The processing module 230 may be configured to receive a detection voltage from the detection voltage acquisition module 210 and a reference voltage from the reference voltage acquisition module 220. Although not shown in Fig. 2, the faultdetection circuit may further include one or more memories having one or more computer program modules stored thereon. One or more computer program modules may be configured to be read and executed by the processing module 230. The one or more computer program modules include a method for comparing a reference voltage and a detection voltage to determine a short-circuit fault in a switching element according to at least one embodiment of the present disclosure. When the one or more computer program modules are executed by the processing module 230, the steps of the method for comparing the reference voltage and the detection voltage to determine the short-circuit fault in the switching element according to at least one embodiment of the present disclosure can be performed.

[0042] The memory and the processing module 230 may be interconnected via a bus system and / or other forms of connection mechanisms (not shown). For example, the bus may be a peripheral component interconnect standard (PCI) bus, an extended industry standard architecture (EISA) bus, or the like. The communication bus may be divided into an address bus, a data bus, a control bus, etc.

[0043] 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), other forms of processing units with data processing capabilities and / or program execution capabilities, such as a field-programmable gate array (FPGA), or the like. The processing module 230 may be a general-purpose processor or a special-purpose processor, which may control other components in the fault detection circuit 200 to perform desired functions.

[0044] Illustratively, 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. The volatile memory may include, for example, a random access memory (RAM) and / or a cache memory (cache), etc. The non-volatile memory may include, for example, a read-only memory (ROM), a hard disk, an erasable programmable read-only memory (EPROM), a portable compact disc read-only memory (CD-ROM), a USB storage, a flash memory, etc. One or more computer program modules may be stored on the computer-readable storage medium, and the processing module 230 may runone 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.

[0045] Fig. 3 is a schematic diagram of a fault detection circuit according to an embodiment of the present disclosure. Elements identical to those in Fig. 2 in Fig.

[0046] 3 will not be described again.

[0047] The fault detection circuit 300 may be connected between the high-voltage end and the low- voltage end 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.

[0048] As shown in Fig. 3, 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 a voltage applied to at least one of the fifth resistor R5 and the sixth resistor R6.

[0049] According to an embodiment of the present disclosure, the reference voltage may include a first reference voltage VREF_I and a second reference voltage VREF_2. The first reference voltage VREF_I may correspond to a high reference voltage, and the second reference voltage VREF_2 may correspond to a low reference voltage. The processing module 230 may obtain the first reference voltage VREF_I from between the fourth resistor R4 and the fifth resistor R5 as a voltage applied to the fifth resistor R5 and the sixth resistor R6, and the processing module 230 may obtain the second reference voltage VREF_2 from between the fifth resistor R5 and the sixth resistor R6 as a voltage applied to the sixth resistor R6. Specifically, the first reference voltage VREF_I may be obtained by the following equation (1):

[0050] "

[0051]

[0052] where VpoWer is the power supply voltage of power supply 140, and r4, r5 and r6 are the resistance values of the fourth resistor R4, the fifth resistor R5 and the sixth resistor R6, respectively.The second reference voltage VREF_2 may be obtained through the following equation (2):

[0053]

[0054] 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 a faulty switching element, the first reference voltage VREF_I and the second reference voltage VREF_2 output by the reference voltage acquisition module 220 may remain unchanged.

[0055] In the absence of short-circuit faults in the switching elements 111 and 112, the detection voltage obtained by the processing module 230 from between the second resistor R2 and the third resistor R3 included in the detection voltage acquisition module 210 may be obtained by the following equation (3):

[0056]

[0057] where rl, r2 and r3 are the resistance values of the first resistor Rl, the second resistor R2 and the third resistor R3, respectively.

[0058] In the case where a short-circuit fault has occurred in the switching element 111 of the switching elements 111 and 112 and no short-circuit fault has occurred in the switching element 112, the detection voltage obtained by the processing module 230 may be obtained by the following equation (4):

[0059]

[0060] In the case where a short-circuit fault has occurred in the switching element 112 of the switching elements 111 and 112 and no short-circuit fault has occurred in the switching element 111, the detection voltage obtained by the processing module 230 may be obtained by the following equation (5):

[0061] cs = 0 (5) According to the above equations (3)-(5), the magnitude relationships between a detection voltage Vcl for indicating that no short-circuit fault has occurred in each of two switching elements in a bridge arm, a detection voltage Vc2 for indicating that a short-circuit fault has occurred in the upper switching element (e.g., theswitching element 111 near the high-voltage end) of the two switching elements in the bridge arm and no short-circuit fault has occurred in the lower switching element (e.g., the switching element 112 near the low-voltage end), and a detection voltage Vc3 for indicating that a short-circuit fault has occurred in the lower switching element (e.g., the switching element 112 near the low- voltage end) of the two switching elements in the bridge arm and no short-circuit fault has occurred in the upper switching element (e.g., the switching element 111 near the high-voltage end) are derived. The magnitude relationships between Vcl, Vc2, and Vc3 are shown in the following equation (6):

[0062] Vc3< Vcl < Vc2(6) By reasonably 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 cause Vcl, Vc2, and Vc3 to have the magnitude relationships as shown in the following equations (7)-(9) with the first reference voltage VREF_I and the second reference voltage VREF_2:

[0063] VREF_2 < VC1< VREF_I (7) VC3 < VREF2 (8) Vc2> VREF.I (9) That is, the processing module 230 may be configured to compare the detection voltage detected by the detection voltage acquisition module 210 (e.g., in real time) with a first reference voltage VREF_I and a second reference voltage VREF_2 separately. In response to the detection 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 elements of the bridge arm. In response to the detection voltage being greater than the first reference voltage VREF_I, the processing module 230 can determine that a short-circuit fault has occurred in one switching element (e.g., the switching element 111 near the high-voltage end) included in the switching elements. In response to the detection voltage being less than the second reference voltage VREF_2, the processing module 230 can determine that a short-circuit fault has occurred in another switching element (e.g., theswitching element 112 near the low- voltage end) included in the switching elements. Fig. 4 is a schematic diagram of a fault detection circuit according to an embodiment of the present disclosure. Elements identical to those in Fig. 2 in Fig.

[0064] 3 will not be described again.

[0065] The fault detection circuit 400 may be connected between the high-voltage end and the low- voltage end 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.

[0066] As shown in Fig. 4, 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 a voltage applied to the eighth resistor R8.

[0067] The processing module 230 may be configured to obtain a reference voltage from between the seventh resistor R7 and the eighth resistor R8 as a voltage applied to the eighth resistor R8, and calculate the power supply voltage on the basis of the pre-configured resistance values of the seventh resistor R7 and the eighth resistor R8 and the reference voltage. Specifically, the processing module 230 may calculate the power supply voltage on the basis of the following equation (10):

[0068]

[0069] where VpOwer is the calculated power supply voltage, VREF is the reference voltage obtained by the processing module 230 from between the seventh resistor R7 and the eighth resistor R8, and 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 the processing module 230 can be reduced. For example, the processing module 230 obtains the divided voltage of the eighth resistor R8 as the reference voltage instead of directly obtaining the power supply voltage, thereby protecting the processing module 230 from high voltage damage.

[0070] On the basis of the power supply voltage VpoWer and the pre-configured resistance values of the first resistor R1 to the third resistor R3, the processingmodule 230 can calculate, as shown in equations (3)-(5), a detection voltage Vcl for indicating that no short-circuit fault has occurred in each of two switching elements in a bridge arm, a detection voltage Vc2 for indicating that a short-circuit fault has occurred in the upper switching element (e.g., the switching element 111 near the high-voltage end) of the two switching elements in the bridge arm and no short-circuit fault has occurred in the lower switching element (e.g., the switching element 112 near the low-voltage end), and a detection voltage Vc3 for indicating that a short-circuit fault has occurred in the lower switching element (e.g., the switching element 112 near the low- voltage end) of the two switching elements in the bridge arm and no short-circuit fault has occurred in the upper switching element (e.g., the switching element 111 near the high-voltage end).

[0071] According to an embodiment of the present disclosure, the processing module 230 may compare the detection voltage detected by the detection voltage acquisition module 210 (e.g., in real time) with the detection voltages Vcl, Vc2, and Vc3 to determine whether a short-circuit fault has occurred in the switching elements of the bridge arm and which of the switching elements has experienced the short-circuit fault.

[0072] According to another embodiment of the present disclosure, the processing module 230 may be further configured to calculate a first threshold voltage and a second threshold voltage.

[0073] The processing module 230 can determine the first threshold voltage according to the following equation (11):

[0074]

[0075] The processing module 230 can determine the second threshold voltage according to the following equation (12):

[0076] V„fL = Vcl+ / 2 (12) That is, the processing module 230 can determine, as the first threshold voltage, half of the sum of the detection voltage Vcl for indicating that no short-circuit fault has occurred in the switching elements in the bridge arm, and the detection voltage Vc2 for indicating that the switching element 111 near the high-voltage end in the bridge arm has experienced a short-circuit fault, and determine, as the secondthreshold voltage, half of the sum of the detection voltage Vol, which is a normal voltage, and the detection voltage Vc3 for indicating that the switching element 112 near the low- voltage end in the bridge arm has experienced a short-circuit fault.

[0077] The processing module 230 can compare the detection voltage detected by the detection voltage acquisition module 210 (e.g., in real time) with the first threshold voltage and the second threshold voltage, respectively. In response to the detection voltage being between the first threshold voltage and the second threshold voltage, the processing module 230 can determine that no short-circuit fault has occurred in each of the switching elements included in the bridge arm. In response to the detection 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 switching elements included in the bridge arm. In response to the detection 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 switching elements included in the bridge arm. In this hysteresis manner, the robustness of the fault detection circuit's detection results can be improved, avoiding false alarms.

[0078] The fault detection circuit shown in Figs. 3 and 4 has the advantage of obtaining a more accurate reference voltage compared with the processing module 230 directly determining the reference voltage on the basis of the rated power supply voltage of the power supply. Since the output voltage of a power supply (e.g., a battery) may fluctuate greatly under different states (high current discharge, low current discharge, different states of charge, etc.), the reference voltage obtained in real time by the reference voltage acquisition module 220 can be more accurate.

[0079] Although each of the resistors R1-R8 is shown as a single resistor in Figs. 2-4, it can be understood by those skilled in the art that one or more of the resistors Rl-R8 can be formed by connecting multiple resistors in series for purposes such as voltage division.

[0080] According to one aspect of the embodiments of the present disclosure, a bridge inverter circuit as shown in Fig. 1 can be provided. The bridge inverter circuit includes one or more bridge arms, and at least one of the one or more bridge armsis configured with the fault detection circuit as shown in Figs. 2-4, which will not be described in detail here for the sake of brevity.

[0081] Fig. 5 is a schematic diagram of a vehicle according to an embodiment of the present disclosure.

[0082] The vehicle 500 may include, but is not limited to, a sedan, a tractor unit (with or without a trailer), a bus, a recreational vehicle, a minivan or a sport utility vehicle (SUV), etc.

[0083] As shown in Fig. 5, the vehicle 500 may include a device 510, which may be the fault detection circuit 200-400 described above or the bridge inverter circuit described above.

[0084] The fault detection circuit, bridge inverter circuit, and vehicle according to the embodiments of the present disclosure provide a solution that can detect potential short-circuit faults in the switching elements before the bridge inverter converts DC power, thereby preventing more extensive damage to circuit components due to the short-circuit faults. The fault detection circuit according to the present disclosure is low in complexity, easy to implement, and has low hardware cost.

[0085] Although the present disclosure has been described using exemplary embodiments, various changes and modifications could be suggested to a person skilled in the art. The present disclosure is intended to encompass such changes and modifications that fall within the scope of the attached claims.

[0086] Nothing described in the present invention should be construed as implying that any specified element, step or function is an essential element that must be included in the scope of the claims. The scope of the patent subject matter is only defined by the claims.

Claims

Claims1. A fault detection circuit, used for detecting a short-circuit fault in switching elements of a bridge arm of a bridge inverter, with a detection point provided between the switching elements in the bridge arm, the fault detection circuit being connected between a high-voltage end and a low- voltage end of the bridge inverter, wherein the fault detection circuit comprises:a detection voltage acquisition module configured to acquire a detection voltage, the detection voltage acquisition module comprising a first resistor, a second resistor, and a third resistor connected in series between the high-voltage end and the low-voltage end, and the detection point being connected between the first resistor and the second resistor, wherein a 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 a power supply voltage; anda 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, on the basis of a comparison result, whether a short-circuit fault has occurred in one of the switching elements.

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

3. The fault detection circuit according to claim 2, wherein the referencevoltage comprises a first reference voltage and a second reference voltage, and whereinthe processing module obtains the first reference voltage from between the fourth resistor and the fifth resistor as a voltage applied to the fifth resistor and the sixth resistor, andthe processing module obtains the second reference voltage from between the fifth resistor and the sixth resistor as a voltage applied to the sixth resistor.

4. The fault detection circuit according to claim 3, wherein the processing module is configured to:compare the detection voltage with the first reference voltage and the second reference voltage separately;in response to the detection voltage being between the first reference voltage and the second reference voltage, determine that no short-circuit fault has occurred in the switching elements;in response to the detection voltage being greater than the first reference voltage, determine that a short-circuit fault has occurred in a first switching element comprised in the switching elements; andin response to the detection voltage being less than the second reference voltage, determine that a short-circuit fault has occurred in a second switching element comprised in the switching elements.

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

6. The fault detection circuit according to claim 5, wherein the processing module is configured to:obtain a reference voltage from between the fourth resistor and the fifth resistor as a voltage applied to the fifth resistor,calculate a power supply voltage on the basis of the reference voltage and resistance values of the fourth resistor and the fifth resistor, andcalculate a first threshold voltage and a second threshold voltage on the basisof the power supply voltage, andthe first threshold voltage and the second threshold voltage are calculated on the basis of the following:the power supply voltage is multiplied by a ratio of a resistance value of the third resistor to a sum of resistance values of the first resistor, the second resistor and the third resistor to obtain a normal voltage,the power supply voltage is multiplied by a ratio of the resistance value of the third resistor to a sum of resistance values of the second resistor and the third resistor to obtain a first fault voltage,zero is used as a second fault voltage,half of a sum of the normal voltage and the first fault voltage is determined as the first threshold voltage, andhalf of a sum of the normal voltage and the second fault voltage is determined as the second threshold voltage.

7. The fault detection circuit according to claim 6, wherein the processing module is configured to:compare the detection voltage with the first threshold voltage and the second threshold voltage separately;in response to the detection voltage being between the first threshold voltage and the second threshold voltage, determine that no short-circuit fault has occurred in the switching elements;in response to the detection voltage being greater than the first threshold voltage, determine that a short-circuit fault has occurred in a first switching element comprised in the switching elements; andin response to the detection voltage being less than the second threshold voltage, determine that a short-circuit fault has occurred in a second switching element comprised in the switching elements.

8. The fault detection circuit according to claim 1, wherein the switching elements comprise 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.

9. Abridge inverter circuit, comprising:one or more bridge arms, andthe fault detection circuit according to any one of claims 1-8.

10. A vehicle, comprising the fault detection circuit according to any one of claims 1-8 or the bridge inverter circuit according to claim 9.

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