Multi-IGBT parallel fault detection circuit

Abstract

The invention relates to the technical field of semiconductors, in particular to a multi-IGBT parallel fault detection circuit which comprises a fault detection module, the first end of the fault detection module is connected with the positive direct current ends of a plurality of IGBTs connected in parallel, and the second end of the fault detection module is connected with the input end of an IGBT driving circuit; the IGBT driving circuit is used for receiving the driving signal and controlling the on-off states of the plurality of IGBTs according to the driving signal; and the fault detection module is used for carrying out fault detection on the plurality of IGBTs according to the voltage of the positive direct current end and the driving signal to obtain a fault detection result. By the adoption of the scheme, fault detection of multiple IGBTs connected in parallel can be achieved.

Description

Technical Field

[0001] The present disclosure relates to the field of semiconductor technology, and in particular to a multi-IGBT parallel fault detection circuit. Background Art

[0002] Insulate-Gate Bipolar Transistor (IGBT) combines the advantages of Giant Transistor (GTR) and Power MOSFET, has good characteristics, and is widely used. However, in the prior art, when driving multiple IGBTs connected in parallel, the fault detection and feedback protection of multiple IGBTs in parallel are not considered, resulting in frequent burnout of IGBT devices due to overvoltage. Summary of the invention

[0003] The present disclosure provides a multi-IGBT parallel fault detection circuit, the main purpose of which is to realize fault detection of multiple IGBTs in parallel.

[0004] According to one aspect of the present disclosure, a multi-IGBT parallel fault detection circuit is provided, comprising:

[0005] A fault detection module, wherein a first end of the fault detection module is connected to the positive DC ends of the plurality of IGBTs connected in parallel, and a second end of the fault detection module is connected to an input end of an IGBT drive circuit;

[0006] The IGBT driving circuit is used to receive a driving signal and control the on / off states of the multiple IGBTs according to the driving signal;

[0007] The fault detection module is used to perform fault detection on the multiple IGBTs according to the voltage of the positive DC terminal and the driving signal to obtain a fault detection result.

[0008] Optionally, in an embodiment of the present disclosure, the fault detection module includes a fault detection unit and a result feedback unit, wherein a first end of the fault detection unit is connected to the positive DC ends of a plurality of IGBTs connected in parallel, a second end of the fault detection unit is connected to the second end of the result feedback unit and the input end of the IGBT drive circuit, and a third end of the fault detection unit is connected to the third end of the result feedback unit; wherein,

[0009] The fault detection unit is used to perform fault detection on the multiple IGBTs according to the voltage of the positive DC terminal and the driving signal to obtain a fault detection result;

[0010] The result feedback unit is used to send a fault feedback signal corresponding to the fault detection result.

[0011] Optionally, in one embodiment of the present disclosure, the fault detection unit includes a first resistor, a second resistor, a third resistor, a fourth resistor, a first capacitor, a second capacitor and a transient suppression diode; wherein,

[0012] A connection point between the first end of the first resistor, the first end of the first capacitor, and the positive electrode of the transient suppression diode is connected to the third end of the result feedback unit, a connection point between the second end of the first resistor and the second end of the first capacitor is used to receive a first negative DC power supply voltage, a negative electrode of the transient suppression diode is respectively connected to the first end of the second resistor, the first end of the third resistor, the first end of the fourth resistor, and the first end of the second capacitor, a second end of the second resistor is respectively connected to the second end of the result feedback unit and the input end of the IGBT drive circuit, a connection point between the second end of the third resistor and the second end of the second capacitor is used to receive a second negative DC power supply voltage, and a second end of the fourth resistor is connected to positive DC ends of a plurality of IGBTs connected in parallel;

[0013] When the multiple IGBTs are in a fault state, a voltage corresponding to a connection point between the first end of the first resistor, the first end of the first capacitor, and the anode of the transient suppression diode is greater than a voltage threshold.

[0014] Optionally, in an embodiment of the present disclosure, the fault detection unit further includes a first protection subunit, a second protection subunit and a third protection subunit; wherein,

[0015] The first end of the first protection subunit is connected to the cathode of the transient suppression diode, and the second end of the first protection subunit is respectively connected to the first end of the second resistor, the first end of the third resistor, the first end of the fourth resistor and the first end of the second capacitor;

[0016] The first end of the second protection subunit is connected to the second end of the second resistor, and the second end of the second protection subunit is connected to the second end of the result feedback unit and the input end of the IGBT drive circuit respectively;

[0017] The first end of the third protection subunit is connected to the second end of the third resistor, and the connection point between the second end of the third protection subunit and the second end of the second capacitor is used to receive a second negative DC power supply voltage.

[0018] Optionally, in an embodiment of the present disclosure, the first protection subunit includes a first diode, the second protection subunit includes a second diode, and the third protection subunit includes a third diode; wherein,

[0019] The cathode of the first diode is connected to the cathode of the transient voltage suppression diode, and the anode of the first diode is respectively connected to the first end of the second resistor, the first end of the third resistor, the first end of the fourth resistor, and the first end of the second capacitor;

[0020] The cathode of the second diode is connected to the second end of the second resistor, and the anode of the second diode is connected to the second end of the result feedback unit and the input end of the IGBT driving circuit respectively;

[0021] The cathode of the third diode is connected to the second end of the third resistor, and the connection point between the anode of the third diode and the second end of the second capacitor is used to receive a second negative DC power supply voltage.

[0022] Optionally, in one embodiment of the present disclosure, the fault detection unit further includes a fourth diode; wherein,

[0023] An anode of the fourth diode is connected to the second end of the fourth resistor, and a cathode of the fourth diode is connected to positive DC terminals of a plurality of IGBTs connected in parallel.

[0024] Optionally, in an embodiment of the present disclosure, the result feedback unit includes a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a third capacitor, a first N-type switch tube and a second N-type switch tube; wherein,

[0025] A connection point between the first end of the fifth resistor and the first end of the sixth resistor is used to receive a first positive DC power supply voltage, a connection point between the second end of the fifth resistor and the collector of the first N-type switch tube is used to send a fault feedback signal, an emitter of the first N-type switch tube is used to receive a third negative DC power supply voltage, a gate of the first N-type switch tube is respectively connected to the first end of the seventh resistor, the first end of the third capacitor, the first end of the eighth resistor, the second end of the sixth resistor and the collector of the second N-type switch tube, a gate of the second N-type switch tube is connected to the third end of the fault detection unit, an emitter of the second N-type switch tube is used to receive a fourth negative DC power supply voltage, a connection point between the second end of the seventh resistor and the second end of the third capacitor is used to receive a fifth negative DC power supply voltage, a connection point between the second end of the eighth resistor and the first end of the ninth resistor is used to receive an initial drive signal, and a second end of the ninth resistor is respectively connected to the second end of the fault detection unit and the input end of the IGBT drive circuit.

[0026] Optionally, in an embodiment of the present disclosure, the result feedback unit further includes a fourth protection subunit; wherein,

[0027] The first end of the fourth protection subunit is respectively connected to the gate of the first N-type switch tube, the first end of the seventh resistor, the first end of the third capacitor, the second end of the sixth resistor and the collector of the second N-type switch tube, and the second end of the fourth protection subunit is connected to the first end of the eighth resistor.

[0028] Optionally, in one embodiment of the present disclosure, the fourth protection subunit includes a fifth diode; wherein,

[0029] The cathode of the fifth diode is respectively connected to the gate of the first N-type switch tube, the first end of the seventh resistor, the first end of the third capacitor, the second end of the sixth resistor and the collector of the second N-type switch tube, and the anode of the fifth diode is connected to the first end of the eighth resistor.

[0030] Optionally, in an embodiment of the present disclosure, when the result feedback unit is used to send a fault feedback signal corresponding to the fault detection result, it is specifically used to:

[0031] When the voltage corresponding to the gate of the second N-type switch tube is greater than the voltage threshold, the second N-type switch tube is in the on state, the first N-type switch tube is in the off state, and the result feedback unit sends a high-level fault feedback signal, and the high-level fault feedback signal is used to indicate that the IGBT is in a fault state;

[0032] When the voltage corresponding to the gate of the second N-type switch tube is not greater than the voltage threshold, the second N-type switch tube is in an off state, the first N-type switch tube is in an on state, and the result feedback unit sends a low-level fault feedback signal, and the low-level fault feedback signal is used to indicate that the IGBT is in a non-fault state.

[0033] In summary, the multi-IGBT parallel fault detection circuit provided in the embodiment of the present disclosure performs fault detection on multiple IGBTs according to the voltage at the positive DC terminal and the driving signal through the fault detection module to obtain a fault detection result. Therefore, fault detection of multiple IGBTs in parallel can be implemented, so that feedback protection can be performed on the multiple IGBTs according to the fault detection results, thereby reducing the frequent burning of IGBT devices due to overvoltage.

[0034] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0036] Figure 1 A schematic diagram of a multi-IGBT parallel fault detection circuit provided by an embodiment of the present disclosure;

[0037] Figure 2 A schematic structural diagram of a multi-IGBT parallel fault detection circuit provided by another embodiment of the present disclosure. DETAILED DESCRIPTION

[0038] Some embodiments of the present disclosure will be described in detail here, and examples thereof are shown in the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. Various changes, modifications and equivalents of the structures described herein will become apparent after understanding the present disclosure. For example, the connection relationships of the structures described herein are merely examples and are not limited to those connection relationships set forth herein, but can be changed as becomes apparent after understanding the present disclosure, except for connections that must be made with specific connection relationships. In addition, for clarity and brevity, descriptions of features known in the art may be omitted.

[0039] The embodiments described in some embodiments of the present disclosure below do not represent all embodiments consistent with the present disclosure. Instead, they are merely examples of structures consistent with some aspects of the present disclosure as detailed in the appended claims.

[0040] The present disclosure is described in detail below with reference to specific embodiments.

[0041] Figure 1 This is a schematic diagram of a multi-IGBT parallel fault detection circuit provided by an embodiment of the present disclosure. Figure 1 As shown, the multi-IGBT parallel fault detection circuit includes:

[0042] A fault detection module, wherein a first end of the fault detection module is connected to the positive DC ends of a plurality of IGBTs connected in parallel, and a second end of the fault detection module is connected to the input end of the IGBT drive circuit.

[0043] According to some embodiments, an IGBT driving circuit is used to receive a driving signal and control the on and off states of a plurality of IGBTs according to the driving signal.

[0044] In some embodiments, when an IGBT among the multiple IGBTs is an N-type IGBT, the positive DC terminal of the IGBT is the collector and the negative DC terminal is the emitter; when an IGBT among the multiple IGBTs is a P-type IGBT, the positive DC terminal of the IGBT is the emitter and the negative DC terminal is the collector.

[0045] According to some embodiments, the fault detection module is used to perform fault detection on multiple IGBTs according to the voltage at the positive DC terminal and the drive signal to obtain a fault detection result. Therefore, fault detection of multiple IGBTs in parallel can be realized, so that feedback protection can be performed on the multiple IGBTs according to the fault detection result, thereby reducing the frequent burning of IGBT devices due to overvoltage.

[0046] Optionally, in one embodiment of the present disclosure, Figure 2 This is a schematic diagram of a multi-IGBT parallel fault detection circuit provided by an embodiment of the present disclosure. Figure 2 As shown, the multi-IGBT parallel fault detection circuit includes N N-type IGBTs, IGBT1 to IGBTN, where N is a positive integer greater than 1. The collectors of the N N-type IGBTs are all connected to a positive DC power supply DC+, and the emitters of the N N-type IGBTs are all connected to a negative DC power supply DC-, thereby realizing parallel connection of the N N-type IGBTs.

[0047] According to some embodiments, the gate of the IGBT is used to receive the target drive signal sent by the IGBT drive circuit. The target drive signals received by different IGBTs may be the same or different, which may be determined according to the actual application scenario. The IGBT may be turned on and off according to the received target drive signal.

[0048] In some embodiments, if the multiple IGBTs connected in parallel are P-type IGBTs, the emitters of the P-type IGBTs are all connected to the positive DC power supply DC+, and the collectors of the P-type IGBTs are all connected to the negative DC power supply DC-.

[0049] Optionally, in one embodiment of the present disclosure, the fault detection module includes a fault detection unit and a result feedback unit, a first end of the fault detection unit is connected to the positive DC ends of multiple IGBTs connected in parallel, a second end of the fault detection unit is connected to the second end of the result feedback unit and the input end of the IGBT drive circuit, and a third end of the fault detection unit is connected to the third end of the result feedback unit.

[0050] In some embodiments, the fault detection unit is used to perform fault detection on the plurality of IGBTs according to the voltage at the positive DC terminal and the driving signal to obtain a fault detection result;

[0051] According to some embodiments, the result feedback unit is used to send a fault feedback signal corresponding to the fault detection result.

[0052] In some embodiments, when the fault detection result indicates that the IGBT is in a fault state, the fault feedback signal also indicates that the IGBT is in a fault state; when the fault detection result indicates that the IGBT is in a non-fault state, the fault feedback signal also indicates that the IGBT is in a non-fault state.

[0053] It should be noted that, by sending a fault feedback signal corresponding to the fault detection result, feedback protection can be implemented when multiple IGBTs are connected in parallel, thereby reducing the frequent burning of IGBT devices due to overvoltage.

[0054] Optionally, in one embodiment of the present disclosure, Figure 2 As shown, the fault detection unit includes a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a first capacitor C1, a second capacitor C2 and a transient suppression diode DZ1; wherein,

[0055] A connection point between the first end of the first resistor R1, the first end of the first capacitor C1, and the positive electrode of the transient suppression diode DZ1 is connected to the third end of the result feedback unit, a connection point between the second end of the first resistor R1 and the second end of the first capacitor C1 is used to receive a first negative DC power supply voltage, a negative electrode of the transient suppression diode DZ1 is respectively connected to the first end of the second resistor R2, the first end of the third resistor R3, the first end of the fourth resistor R4, and the first end of the second capacitor C2, a second end of the second resistor R2 is respectively connected to the second end of the result feedback unit and the input end of the IGBT drive circuit, a connection point between the second end of the third resistor R3 and the second end of the second capacitor C2 is used to receive a second negative DC power supply voltage, and a second end of the fourth resistor R4 is connected to the positive DC ends of a plurality of IGBTs connected in parallel.

[0056] According to some embodiments, the voltage at the connection point between the first end of the first resistor R1, the first end of the first capacitor C1, and the anode of the transient suppression diode DZ1 includes the following situations:

[0057] When the driving signal is at a low level, under normal working conditions, the IGBT is in an off state, and the input end of the IGBT driving circuit, the first end of the first resistor R1, the first end of the second resistor R2, and the first end of the first capacitor C1 are all at low voltage;

[0058] When the driving signal is at a high level, under normal working conditions, the IGBT is in an on state, the input end of the IGBT driving circuit is at a high level, and the levels of the first end of the second resistor R2 and the first end of the third resistor R3 are increased from a low level to a high level. When the IGBT is normally turned on, the voltage across the second resistor R2 and the third resistor R3 does not exceed the withstand voltage of the transient suppression diode DZ1, and the voltage at the connection point between the first end of the first resistor R1, the first end of the first capacitor C1, and the positive electrode of the transient suppression diode DZ1 is still a low voltage;

[0059] When the driving signal is at a high level, the IGBT is in a short-circuit state, and the on-current of the IGBT increases instantaneously, which will cause the on-voltage drop of the parallel IGBT to increase, thereby causing the voltage across the second resistor R2 and the third resistor R3 to rise until it is higher than the withstand voltage of the transient suppression diode DZ1, causing the transient suppression diode DZ1 to be turned on, thereby causing the voltage at the connection point between the first end of the first resistor R1, the first end of the first capacitor C1, and the positive electrode of the transient suppression diode DZ1 to rise to a high voltage.

[0060] That is to say, when the multiple IGBTs are in a fault state, the voltage corresponding to the connection point between the first end of the first resistor R1, the first end of the first capacitor C1, and the anode of the transient suppression diode DZ1 is greater than the voltage threshold, that is, the fault detection result when the multiple IGBTs are in a fault state. When the multiple IGBTs are in a non-fault state, the voltage corresponding to the connection point between the first end of the first resistor R1, the first end of the first capacitor C1, and the anode of the transient suppression diode DZ1 is not greater than the voltage threshold, that is, the fault detection result when the multiple IGBTs are in a non-fault state.

[0061] In some embodiments, the voltage threshold does not specifically refer to a fixed threshold, and the voltage threshold can be determined according to actual application scenarios.

[0062] According to some embodiments, the resistance values ​​of the second resistor R2, the third resistor R3, and the fourth resistor R4 can be adjusted according to the actual application scenario, as long as the voltage across the second resistor R2 and the third resistor R3 is higher than the withstand voltage of the transient suppression diode DZ1 when the IGBT is abnormally turned on.

[0063] In some embodiments, the resistance value of the first resistor R1 can be adjusted according to the actual application scenario, as long as the voltage corresponding to the first end of the first resistor R1 is greater than the voltage threshold when the IGBT is abnormally turned on.

[0064] According to some embodiments, the first negative DC power supply voltage does not specifically refer to a fixed voltage. The first negative DC power supply voltage can be determined according to the actual application scenario. For example, the first negative DC power supply voltage can be -15V, such as Figure 2 shown.

[0065] Optionally, in an embodiment of the present disclosure, the fault detection unit further includes a first protection subunit, a second protection subunit and a third protection subunit; wherein,

[0066] A first end of the first protection subunit is connected to the cathode of the transient suppression diode, and a second end of the first protection subunit is respectively connected to the first end of the second resistor, the first end of the third resistor, the first end of the fourth resistor, and the first end of the second capacitor;

[0067] A first end of the second protection subunit is connected to a second end of the second resistor, and a second end of the second protection subunit is connected to a second end of the result feedback unit and an input end of the IGBT drive circuit respectively;

[0068] The first end of the third protection subunit is connected to the second end of the third resistor, and the connection point between the second end of the third protection subunit and the second end of the second capacitor is used to receive the second negative DC power supply voltage.

[0069] According to some embodiments, by providing a first protection subunit, a second protection subunit, and a third protection subunit to protect the circuit, the reliability of the circuit can be improved.

[0070] In some embodiments, Figure 2 As shown, the first protection subunit includes a first diode D1, the second protection subunit includes a second diode D2, and the third protection subunit includes a third diode D3; wherein,

[0071] The cathode of the first diode D1 is connected to the cathode of the transient suppression diode DZ1, and the anode of the first diode D1 is respectively connected to the first end of the second resistor R2, the first end of the third resistor R3, the first end of the fourth resistor R4, and the first end of the second capacitor C2;

[0072] The cathode of the second diode D2 is connected to the second end of the second resistor R2, and the anode of the second diode D2 is connected to the second end of the result feedback unit and the input end of the IGBT driving circuit respectively;

[0073] The cathode of the third diode D3 is connected to the second end of the third resistor R3 , and the connection point between the anode of the third diode D3 and the second end of the second capacitor C2 is used to receive the second negative DC power supply voltage.

[0074] In some embodiments, the second negative DC power supply voltage does not specifically refer to a fixed voltage. The second negative DC power supply voltage can be determined according to the actual application scenario. For example, the second negative DC power supply voltage can be -15V, such as Figure 2 shown.

[0075] In some embodiments, by providing a first diode D1, a second diode D2 and a third diode D3, components in a multi-IGBT parallel fault detection circuit can be protected to avoid overvoltage and absorb overvoltage energy in the circuit, thereby improving the reliability of the multi-IGBT parallel fault detection circuit.

[0076] Optionally, in one embodiment of the present disclosure, Figure 2 As shown, the fault detection unit also includes a fourth diode D4; wherein,

[0077] An anode of the fourth diode D4 is connected to the second end of the fourth resistor R4 , and a cathode of the fourth diode D4 is connected to the positive DC terminals of the plurality of IGBTs connected in parallel.

[0078] According to some embodiments, when the turn-off overvoltage of the IGBT exceeds the withstand voltage of the fourth diode D4, it will also cause the voltage corresponding to the connection point between the first end of the first resistor R1, the first end of the first capacitor C1 and the positive electrode of the transient suppression diode DZ1 to be no greater than the voltage threshold, thereby improving the accuracy of fault detection.

[0079] In some embodiments, the fourth diode D4 may be, for example, a fast recovery diode.

[0080] Optionally, in one embodiment of the present disclosure, Figure 2 As shown, the result feedback unit includes a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a third capacitor C3, a first N-type switch tube V01 and a second N-type switch tube V02; wherein,

[0081] A connection point between the first end of the fifth resistor R5 and the first end of the sixth resistor R6 is used to receive the first positive DC power supply voltage, a connection point between the second end of the fifth resistor R5 and the collector of the first N-type switch tube V01 is used to send a fault feedback signal, an emitter of the first N-type switch tube V01 is used to receive a third negative DC power supply voltage, a gate of the first N-type switch tube V01 is respectively connected to the first end of the seventh resistor R7, the first end of the third capacitor C3, the first end of the eighth resistor R8, the second end of the sixth resistor R6 and the collector of the second N-type switch tube V02, a gate of the second N-type switch tube V02 is connected to the third end of the fault detection unit, an emitter of the second N-type switch tube V02 is used to receive a fourth negative DC power supply voltage, a connection point between the second end of the seventh resistor R7 and the second end of the third capacitor C3 is used to receive the fifth negative DC power supply voltage, a connection point between the second end of the eighth resistor R8 and the first end of the ninth resistor R9 is used to receive an initial drive signal, and a second end of the ninth resistor R9 is respectively connected to the second end of the fault detection unit and the input end of the IGBT drive circuit.

[0082] According to some embodiments, Figure 2As shown, for a high-power wind power converter, it includes multiple stages of parallel-connected IGBT devices. The IGBT device is a power semiconductor device in the converter main circuit and is responsible for power conversion. Since the converter core controller, pulse width modulation (PWM) controller and IGBT device are far apart and there is a high voltage and high current environment, the drive signal needs to be transmitted using optical fiber. The PWM optical signal output by the PWM controller can be converted into an electrical signal output through a photoelectric conversion module. The electrical signal after photoelectric conversion is the initial drive signal.

[0083] In some embodiments, Figure 2 As shown, the connection point between the second end of the fifth resistor R5 and the collector of the first N-type switch tube V01 is connected to the first end of the photoelectric conversion module, and the connection point between the second end of the eighth resistor R8 and the first end of the ninth resistor R9 is connected to the second end of the photoelectric conversion module; the gate of the second N-type switch tube V02 is respectively connected to the first end of the first resistor R1, the first end of the first capacitor C1 and the positive electrode of the transient suppression diode DZ1; the second end of the ninth resistor R9 is respectively connected to the positive electrode of the second diode D2 and the input end of the IGBT drive circuit.

[0084] According to some embodiments, the voltage threshold is the on-voltage of the second N-type switch tube V02. When the voltage corresponding to the gate of the second N-type switch tube V02 is greater than the voltage threshold, the second N-type switch tube V02 is in the on state, and then the gate voltage of the first N-type switch tube V01 is pulled down, and the first N-type switch tube V01 is in the off state, so that the connection point between the second end of the fifth resistor R5 and the collector of the first N-type switch tube V01 is at a high level, and as a result, the feedback unit sends a high-level fault feedback signal, and the high-level fault feedback signal is used to indicate that the IGBT is in a fault state.

[0085] In some embodiments, when the voltage corresponding to the gate of the second N-type switch tube V02 is not greater than the voltage threshold, the second N-type switch tube V02 is in an off state, the gate voltage of the first N-type switch tube V01 remains at a high level, and the first N-type switch tube V01 is in an on state, so that the connection point between the second end of the fifth resistor R5 and the collector of the first N-type switch tube V01 is at a low level, and as a result, the feedback unit sends a low-level fault feedback signal, and the low-level fault feedback signal is used to indicate that the IGBT is in a non-fault state.

[0086] According to some embodiments, the ninth resistor R9 can be used as a current limiting resistor to play a protective role. The resistance value of the ninth resistor R9 can be adjusted according to the actual application scenario, as long as the voltage across the second resistor R2 and the third resistor R3 is higher than the withstand voltage of the transient suppression diode DZ1 when the IGBT is abnormally turned on.

[0087] Optionally, in one embodiment of the present disclosure, the result feedback unit further includes a fourth protection subunit; wherein,

[0088] The first end of the fourth protection subunit is respectively connected to the gate of the first N-type switch tube, the first end of the seventh resistor, the first end of the third capacitor, the second end of the sixth resistor and the collector of the second N-type switch tube, and the second end of the fourth protection subunit is connected to the first end of the eighth resistor.

[0089] In some embodiments, the reliability of the circuit can be improved by providing a fourth protection subunit to protect the circuit.

[0090] According to some embodiments, Figure 2 As shown, the fourth protection subunit includes a fifth diode D5; wherein,

[0091] The cathode of the fifth diode D5 is respectively connected to the gate of the first N-type switch tube V01, the first end of the seventh resistor R7, the first end of the third capacitor C3, the second end of the sixth resistor R6 and the collector of the second N-type switch tube V02, and the anode of the fifth diode D5 is connected to the first end of the eighth resistor R8.

[0092] In some embodiments, by providing a fifth diode D5, components in the multi-IGBT parallel fault detection circuit can be protected to avoid overvoltage and absorb overvoltage energy in the circuit, thereby improving the reliability of the multi-IGBT parallel fault detection circuit.

[0093] Optionally, in an embodiment of the present disclosure, all components involved in the multi-IGBT parallel fault detection circuit may be high-precision devices, thereby further improving the accuracy of IGBT parallel fault detection.

[0094] In summary, the multi-IGBT parallel fault detection circuit provided in the embodiment of the present disclosure can monitor the status information of multiple IGBTs in parallel operation in real time, judge the health status of IGBT devices and driving protection circuits, and provide feedback signals for the converter control protection device, thereby ensuring the safe operation of the entire converter.

[0095] In addition, the word "exemplary" is used herein to indicate serving as an example, instance, or diagram. Any aspect or design described as "exemplary" in this article is not necessarily understood to be advantageous compared to other aspects or designs. On the contrary, the use of the word exemplary is intended to present concepts in a specific way. As used herein, the term "or" is intended to represent an inclusive "or" rather than an exclusive "or". That is, unless otherwise specified or clear from the context, "X applies A or B" is intended to represent any one of the natural inclusive arrangements. That is, if X applies A; X applies B; or X applies both A and B, "X applies A or B" is satisfied under any of the aforementioned examples. In addition, unless otherwise specified or clearly pointed to a singular form from the context, the articles "one" and "an" as used in this application and the appended claims are generally understood to mean "one or more".

[0096] Likewise, although the present disclosure has been shown and described with respect to one or more implementations, equivalent variations and modifications will occur to those skilled in the art after reading and understanding the specification and drawings. The present disclosure includes all such modifications and variations and is limited only by the scope of the claims. In particular, with respect to the various functions performed by the components (e.g., elements, resources, etc.) described above, unless otherwise noted, the terms used to describe such components are intended to correspond to any component (functionally equivalent) that performs the specific functions of the described components, even if the structure is not equivalent to the disclosed structure. In addition, although the specific features of the present disclosure may have been disclosed with respect to only one of several implementations, such features may be combined with one or more other features of other implementations as may be desired and conducive to any given or specific application. In addition, with respect to "including", "having", "having", "having", or variations thereof used in the specific embodiments or claims, such terms are intended to be inclusive in a manner similar to the term "comprising".

[0097] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the disclosure disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or customary techniques in the art that are not disclosed in the present disclosure. The description and examples are intended to be exemplary only, and the true scope and spirit of the present disclosure are indicated by the following claims.

[0098] It should be understood that the present disclosure is not limited to the exact structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims

1. A multi-IGBT parallel fault detection circuit, characterized in that: include: A fault detection module, wherein a first end of the fault detection module is connected to the positive DC ends of the plurality of IGBTs connected in parallel, and a second end of the fault detection module is connected to an input end of an IGBT drive circuit; The IGBT driving circuit is used to receive a driving signal and control the on / off states of the multiple IGBTs according to the driving signal; The fault detection module is used to perform fault detection on the multiple IGBTs according to the voltage of the positive DC terminal and the driving signal to obtain a fault detection result.

2. The multi-IGBT parallel fault detection circuit according to claim 1, characterized in that: The fault detection module includes a fault detection unit and a result feedback unit, wherein a first end of the fault detection unit is connected to the positive DC ends of a plurality of IGBTs connected in parallel, a second end of the fault detection unit is connected to a second end of the result feedback unit and an input end of the IGBT drive circuit, and a third end of the fault detection unit is connected to a third end of the result feedback unit; wherein, The fault detection unit is used to perform fault detection on the multiple IGBTs according to the voltage of the positive DC terminal and the driving signal to obtain a fault detection result; The result feedback unit is used to send a fault feedback signal corresponding to the fault detection result.

3. The multi-IGBT parallel fault detection circuit according to claim 2, characterized in that: The fault detection unit includes a first resistor, a second resistor, a third resistor, a fourth resistor, a first capacitor, a second capacitor and a transient suppression diode; wherein, A connection point between the first end of the first resistor, the first end of the first capacitor, and the positive electrode of the transient suppression diode is connected to the third end of the result feedback unit, a connection point between the second end of the first resistor and the second end of the first capacitor is used to receive a first negative DC power supply voltage, a negative electrode of the transient suppression diode is respectively connected to the first end of the second resistor, the first end of the third resistor, the first end of the fourth resistor, and the first end of the second capacitor, a second end of the second resistor is respectively connected to the second end of the result feedback unit and the input end of the IGBT drive circuit, a connection point between the second end of the third resistor and the second end of the second capacitor is used to receive a second negative DC power supply voltage, and a second end of the fourth resistor is connected to positive DC ends of a plurality of IGBTs connected in parallel; When the multiple IGBTs are in a fault state, a voltage corresponding to a connection point between the first end of the first resistor, the first end of the first capacitor, and the anode of the transient suppression diode is greater than a voltage threshold.

4. The multi-IGBT parallel fault detection circuit according to claim 3, characterized in that: The fault detection unit further includes a first protection subunit, a second protection subunit and a third protection subunit; wherein, The first end of the first protection subunit is connected to the cathode of the transient suppression diode, and the second end of the first protection subunit is respectively connected to the first end of the second resistor, the first end of the third resistor, the first end of the fourth resistor and the first end of the second capacitor; The first end of the second protection subunit is connected to the second end of the second resistor, and the second end of the second protection subunit is connected to the second end of the result feedback unit and the input end of the IGBT drive circuit respectively; The first end of the third protection subunit is connected to the second end of the third resistor, and the connection point between the second end of the third protection subunit and the second end of the second capacitor is used to receive a second negative DC power supply voltage.

5. The multi-IGBT parallel fault detection circuit according to claim 4, characterized in that: The first protection subunit includes a first diode, the second protection subunit includes a second diode, and the third protection subunit includes a third diode; wherein, The cathode of the first diode is connected to the cathode of the transient voltage suppression diode, and the anode of the first diode is respectively connected to the first end of the second resistor, the first end of the third resistor, the first end of the fourth resistor, and the first end of the second capacitor; The cathode of the second diode is connected to the second end of the second resistor, and the anode of the second diode is connected to the second end of the result feedback unit and the input end of the IGBT driving circuit respectively; The cathode of the third diode is connected to the second end of the third resistor, and the connection point between the anode of the third diode and the second end of the second capacitor is used to receive a second negative DC power supply voltage.

6. The multi-IGBT parallel fault detection circuit according to claim 3, characterized in that: The fault detection unit further includes a fourth diode; wherein, An anode of the fourth diode is connected to the second end of the fourth resistor, and a cathode of the fourth diode is connected to positive DC terminals of a plurality of IGBTs connected in parallel.

7. The multi-IGBT parallel fault detection circuit according to claim 2, characterized in that: The result feedback unit includes a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a third capacitor, a first N-type switch tube and a second N-type switch tube; wherein, A connection point between the first end of the fifth resistor and the first end of the sixth resistor is used to receive a first positive DC power supply voltage, a connection point between the second end of the fifth resistor and the collector of the first N-type switch tube is used to send a fault feedback signal, an emitter of the first N-type switch tube is used to receive a third negative DC power supply voltage, a gate of the first N-type switch tube is respectively connected to the first end of the seventh resistor, the first end of the third capacitor, the first end of the eighth resistor, the second end of the sixth resistor and the collector of the second N-type switch tube, a gate of the second N-type switch tube is connected to the third end of the fault detection unit, an emitter of the second N-type switch tube is used to receive a fourth negative DC power supply voltage, a connection point between the second end of the seventh resistor and the second end of the third capacitor is used to receive a fifth negative DC power supply voltage, a connection point between the second end of the eighth resistor and the first end of the ninth resistor is used to receive an initial drive signal, and a second end of the ninth resistor is respectively connected to the second end of the fault detection unit and the input end of the IGBT drive circuit.

8. The multi-IGBT parallel fault detection circuit according to claim 7, characterized in that: The result feedback unit also includes a fourth protection subunit; wherein, The first end of the fourth protection subunit is respectively connected to the gate of the first N-type switch tube, the first end of the seventh resistor, the first end of the third capacitor, the second end of the sixth resistor and the collector of the second N-type switch tube, and the second end of the fourth protection subunit is connected to the first end of the eighth resistor.

9. The multi-IGBT parallel fault detection circuit according to claim 8, characterized in that: The fourth protection subunit includes a fifth diode; wherein, The cathode of the fifth diode is respectively connected to the gate of the first N-type switch tube, the first end of the seventh resistor, the first end of the third capacitor, the second end of the sixth resistor and the collector of the second N-type switch tube, and the anode of the fifth diode is connected to the first end of the eighth resistor.

10. The multi-IGBT parallel fault detection circuit according to claim 7, characterized in that: When the result feedback unit is used to send a fault feedback signal corresponding to the fault detection result, it is specifically used to: When the voltage corresponding to the gate of the second N-type switch tube is greater than the voltage threshold, the second N-type switch tube is in the on state, the first N-type switch tube is in the off state, and the result feedback unit sends a high-level fault feedback signal, and the high-level fault feedback signal is used to indicate that the IGBT is in a fault state; When the voltage corresponding to the gate of the second N-type switch tube is not greater than the voltage threshold, the second N-type switch tube is in an off state, the first N-type switch tube is in an on state, and the result feedback unit sends a low-level fault feedback signal, and the low-level fault feedback signal is used to indicate that the IGBT is in a non-fault state.

Images