A multi-igbt parallel fault detection circuit

Abstract

The present disclosure relates to the technical field of semiconductor, and particularly relates to a multi-IGBT parallel fault detection circuit, comprising: a fault detection module, a first end of the fault detection module being connected with a positive direct current end of a plurality of parallelly connected IGBTs, and a second end of the fault detection module being connected with an input end of an IGBT driving circuit; the IGBT driving circuit is used for receiving a driving signal and controlling on-off states of the plurality of IGBTs according to the driving signal; the fault detection module is used for performing fault detection on the plurality of IGBTs according to a voltage of the positive direct current end and the driving signal, and obtaining a fault detection result. The present disclosure adopting the above scheme can realize fault detection of multi-IGBT parallel connection.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of semiconductor technology, and particularly relates to a multi-IGBT parallel fault detection circuit. BACKGROUND

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

[0003] The present disclosure provides a multi-IGBT parallel fault detection circuit, and the main purpose is to realize multi-IGBT parallel fault detection.

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

[0005] a fault detection module, a first end of the fault detection module being connected with a positive direct current end of multiple IGBTs connected in parallel, and a second end of the fault detection module being connected with an input end of an IGBT drive circuit;

[0006] the IGBT drive circuit, configured to receive a drive signal and control on-off states of the multiple IGBTs according to the drive signal;

[0007] the fault detection module, configured to perform fault detection on the multiple IGBTs according to a voltage of the positive direct current end and the drive signal, and obtain a fault detection result.

[0008] Optionally, in an embodiment of the present disclosure, the fault detection module comprises a fault detection unit and a result feedback unit, a first end of the fault detection unit being connected with a positive direct current end of multiple IGBTs connected in parallel, a second end of the fault detection unit being connected with 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 being connected with a third end of the result feedback unit; wherein,

[0009] the fault detection unit, configured to perform fault detection on the multiple IGBTs according to a voltage of the positive direct current end and the drive signal, and obtain a fault detection result;

[0010] the result feedback unit, configured to send a fault feedback signal corresponding to the fault detection result.

[0011] Optionally, in an embodiment of the present disclosure, the fault detection unit comprises a first resistor, a second resistor, a third resistor, a fourth resistor, a first capacitor, a second capacitor and a transient voltage suppressor; wherein,

[0012] a connection point between a first end of the first resistor, a first end of the first capacitor and a positive electrode of the transient voltage suppressor is connected with a third end of the result feedback unit, a connection point between a second end of the first resistor and a second end of the first capacitor is used for receiving a first negative DC power voltage, a negative electrode of the transient voltage suppressor is connected with a first end of the second resistor, a first end of the third resistor, a first end of the fourth resistor and a first end of the second capacitor respectively, a second end of the second resistor is connected with a second end of the result feedback unit and an input end of the IGBT drive circuit respectively, a connection point between a second end of the third resistor and a second end of the second capacitor is used for receiving a second negative DC power voltage, and a second end of the fourth resistor is connected with positive DC ends of the plurality of IGBTs connected in parallel;

[0013] When the plurality of IGBTs are in a fault state, a voltage corresponding to the connection point between the first end of the first resistor, the first end of the first capacitor and the positive electrode of the transient voltage suppressor is greater than a voltage threshold.

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

[0015] a first end of the first protection subunit is connected with a negative electrode of the transient voltage suppressor, and a second end of the first protection subunit is connected with 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 respectively;

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

[0017] a first end of the third protection subunit is connected with a second end of the third resistor, and a connection point between a second end of the third protection subunit and a second end of the second capacitor is used for receiving a second negative DC power voltage.

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

[0019] a negative electrode of the first diode is connected with a negative electrode of the transient suppression diode, and a positive electrode of the first diode is connected with a first end of the second resistor, a first end of the third resistor, a first end of the fourth resistor and a first end of the second capacitor respectively;

[0020] a negative electrode of the second diode is connected with a second end of the second resistor, and a positive electrode of the second diode is connected with a second end of the result feedback unit and an input end of the IGBT drive circuit respectively;

[0021] a negative electrode of the third diode is connected with a second end of the third resistor, and a connection point between a positive electrode of the third diode and a second end of the second capacitor is used for receiving a second negative DC power voltage.

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

[0023] a positive electrode of the fourth diode is connected with a second end of the fourth resistor, and a negative electrode of the fourth diode is connected with positive DC ends of a plurality of IGBTs connected in parallel.

[0024] Optionally, in an embodiment of the present disclosure, the result feedback unit comprises 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 a first end of the fifth resistor and a first end of the sixth resistor is used for receiving a first positive DC power voltage, a connection point between a second end of the fifth resistor and a collector of the first N-type switch tube is used for sending a fault feedback signal, an emitter of the first N-type switch tube is used for receiving a third negative DC power voltage, gates of the first N-type switch tube are connected with a first end of the seventh resistor, a first end of the third capacitor, a first end of the eighth resistor, a second end of the sixth resistor and a collector of the second N-type switch tube respectively, a gate of the second N-type switch tube is connected with a third end of the fault detection unit, an emitter of the second N-type switch tube is used for receiving a fourth negative DC power voltage, a connection point between a second end of the seventh resistor and a second end of the third capacitor is used for receiving a fifth negative DC power voltage, a connection point between a second end of the eighth resistor and a first end of the ninth resistor is used for receiving an initial drive signal, and a second end of the ninth resistor is connected with a second end of the fault detection unit and an input end of the IGBT drive circuit respectively.

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

[0027] The first end of the fourth protection sub-unit is connected with 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 respectively, and the second end of the fourth protection sub-unit is connected with the first end of the eighth resistor.

[0028] Optionally, in an embodiment of the present disclosure, the fourth protection sub-unit comprises a fifth diode; wherein,

[0029] The negative electrode of the fifth diode is connected with 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 respectively, and the positive electrode of the fifth diode is connected with the first end of the eighth resistor.

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

[0031] When the voltage corresponding to the gate of the second N-type switch tube is greater than the voltage threshold value, the second N-type switch tube is in the on state, the first N-type switch tube is in the off state, 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 value, the second N-type switch tube is in the off state, the first N-type switch tube is in the on state, 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 by the embodiment of the present disclosure can detect the faults of the plurality of IGBTs according to the voltage of the positive direct current end and the driving signal through the fault detection module, and obtain the fault detection result. Therefore, the fault detection of the multi-IGBT parallel can be realized, so that the feedback protection of the plurality of IGBTs can be performed according to the fault detection result, and the situation that the IGBT device is frequently burned out due to overvoltage can be reduced.

[0034] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present disclosure. BRIEF DESCRIPTION OF DRAWINGS

[0035] The drawings herein are incorporated into the specification and form a part of the specification, show embodiments consistent with the present disclosure, and together with the specification serve to explain the principles of the present disclosure.

[0036] Figure 1 A structure diagram of a multi-IGBT parallel fault detection circuit according to an embodiment of the present disclosure is shown in FIG. 1.

[0037] Figure 2 A structure diagram of a multi-IGBT parallel fault detection circuit according to another embodiment of the present disclosure is shown in FIG. 2. DETAILED DESCRIPTION

[0038] Some embodiments of the present disclosure will be described in detail with reference to the drawings, of which examples are shown. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. Various changes, modifications, and equivalents of the structures described herein will become apparent to those skilled in the art after understanding the present disclosure. For example, the connecting relationship of the structures described herein is merely an example, and is not limited to those described herein, but can be changed as long as the connection must be made in a specific connection relationship, as long as it becomes apparent after understanding the present disclosure. In addition, the description of features known in the art can be omitted for the sake of clarity and brevity.

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

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

[0041] Figure 1 A structure diagram of a multi-IGBT parallel fault detection circuit according to an embodiment of the present disclosure is shown in FIG. 1. Figure 1 As shown in FIG. 1, the multi-IGBT parallel fault detection circuit includes:

[0042] a fault detection module, a first end of the fault detection module is connected to a positive DC end of a 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.

[0043] According to some embodiments, the IGBT drive circuit is configured to receive a drive signal and control the on-off state of the plurality of IGBTs according to the drive signal.

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

[0045] According to some embodiments, the fault detection module is configured to perform fault detection on the plurality of IGBTs according to the voltage of the positive DC terminal and the driving signal, and obtain a fault detection result. Thus, fault detection on the plurality of IGBTs in parallel can be implemented, so that feedback protection can be performed on the plurality of IGBTs according to the fault detection result, thereby reducing the situation that the IGBT device is frequently burned out due to overvoltage.

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

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

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

[0049] Optionally, in an embodiment of the present disclosure, the fault detection module includes a fault detection unit and a result feedback unit. The first end of the fault detection unit is connected to the positive DC terminal of the plurality of IGBTs connected in parallel, the 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 driving circuit, and the 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 configured to perform fault detection on the plurality of IGBTs according to the voltage of the positive DC terminal and the driving signal, and obtain a fault detection result.

[0051] According to some embodiments, the result feedback unit is configured 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 the fault feedback signal corresponding to the fault detection result, feedback protection when multiple IGBTs are connected in parallel can be achieved, thereby reducing the situation of frequent burnout of IGBT devices due to overvoltage.

[0054] Optionally, in one embodiment of the present disclosure, as shown in Figure 2 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] 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 connected to the third end of the result feedback unit, the 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 voltage, the 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, the 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, the 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 voltage, and the second end of the fourth resistor R4 is connected to the positive DC end of the 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 positive electrode of the transient suppression diode DZ1 includes the following cases:

[0057] When the drive signal is low, under normal working conditions, the IGBT is in an off state, the input end of the IGBT drive 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 low voltage;

[0058] When the drive signal is high, under normal working conditions, the IGBT is in an on state, the input end of the IGBT drive circuit is high, and the level of the first end of the second resistor R2 and the first end of the third resistor R3 is raised from low to high. Under normal conduction of the IGBT, 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 low voltage.

[0059] When the driving signal is at a high level, the IGBT is in a short-circuit state, the conduction current of the IGBT instantaneously increases, which causes the conduction 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, so that the transient suppression diode DZ1 is turned on, and the voltage between the first end of the first resistor R1, the first end of the first capacitor C1, and the connection point of the positive electrode of the transient suppression diode DZ1 rises to a high voltage.

[0060] That is, when the plurality of 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 positive electrode of the transient suppression diode DZ1 is greater than the voltage threshold, that is, the fault detection result when the plurality of IGBTs are in a fault state. When the plurality of 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 positive electrode of the transient suppression diode DZ1 is not greater than the voltage threshold, that is, the fault detection result when the plurality of IGBTs are in a non-fault state.

[0061] In some embodiments, the voltage threshold is not a specific fixed threshold. The voltage threshold can be determined according to the actual application scenario.

[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 is not a specific 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, as shown in Figure 2

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

[0066] The first end of the first protection subunit is connected to the negative electrode of the transient suppression diode, and the second end of the first protection subunit is 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, respectively;

[0067] ​The first end of the second protection sub-unit is connected with the second end of the second resistor, and the second end of the second protection sub-unit is connected with the second end of the result feedback unit and the input end of the IGBT driving circuit respectively.

[0068] The first end of the third protection sub-unit is connected with the second end of the third resistor, and the connection point between the second end of the third protection sub-unit and the second end of the second capacitor is used for receiving the second negative DC power voltage.

[0069] According to some embodiments, by setting the first protection sub-unit, the second protection sub-unit and the third protection sub-unit to protect the circuit, the reliability of the circuit can be improved.

[0070] In some embodiments, as shown in Figure 2 The first protection sub-unit includes a first diode D1, the second protection sub-unit includes a second diode D2, and the third protection sub-unit includes a third diode D3; wherein,

[0071] The negative electrode of the first diode D1 is connected with the negative electrode of the transient suppression diode DZ1, and the positive electrode of the first diode D1 is connected with 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 respectively.

[0072] The negative electrode of the second diode D2 is connected with the second end of the second resistor R2, and the positive electrode of the second diode D2 is connected with the second end of the result feedback unit and the input end of the IGBT driving circuit respectively.

[0073] The negative electrode of the third diode D3 is connected with the second end of the third resistor R3, and the connection point between the positive electrode of the third diode D3 and the second end of the second capacitor C2 is used for receiving the second negative DC power voltage.

[0074] In some embodiments, the second negative DC power voltage is not specified to a certain fixed voltage. The second negative DC power voltage can be determined according to the actual application scenario. For example, the second negative DC power voltage can be -15V, as shown in Figure 2 .

[0075] In some embodiments, by setting the first diode D1, the second diode D2 and the third diode D3, the components in the multi-IGBT parallel fault detection circuit can be protected, overvoltage can be avoided, overvoltage energy in the circuit can be absorbed, and the reliability of the multi-IGBT parallel fault detection circuit can be improved.

[0076] Optionally, in an embodiment of the present disclosure, as shown in Figure 2 The fault detection unit further includes a fourth diode D4; wherein,

[0077] The positive electrode of the fourth diode D4 is connected with the second end of the fourth resistor R4, and the negative electrode of the fourth diode D4 is connected with the positive direct current end 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 value of the fourth diode D4, 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 also not greater than the voltage threshold value, so that the accuracy of fault detection can be improved.

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

[0080] Optionally, in an embodiment of the present disclosure, as shown in Figure 2 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] The 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 direct current source voltage, the 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, the emitter of the first N-type switch tube V01 is used to receive a third negative direct current source voltage, the gate of the first N-type switch tube V01 is connected with 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 respectively, the gate of the second N-type switch tube V02 is connected with the third end of the fault detection unit, the emitter of the second N-type switch tube V02 is used to receive a fourth negative direct current source voltage, the connection point between the second end of the seventh resistor R7 and the second end of the third capacitor C3 is used to receive a fifth negative direct current source voltage, the 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 driving signal, and the second end of the ninth resistor R9 is connected with the second end of the fault detection unit and the input end of the IGBT driving circuit respectively.

[0082] According to some embodiments, as shown in Figure 2As shown, for a high-power wind power converter, it includes a plurality of parallel IGBT devices, which are power semiconductor devices of the main circuit of the converter, responsible for power conversion. Due to the long distance between the core controller of the converter, the pulse width modulation (PWM) controller and the IGBT device, and the high voltage and large current environment, the driving signal needs to be transmitted by optical fiber. The PWM optical signal output by the PWM controller can be converted into an electrical signal output by an optoelectronic conversion module. The electrical signal after optoelectronic conversion is the initial driving signal.

[0083] In some embodiments, as shown in 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 with the first end of the optoelectronic 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 with the second end of the optoelectronic conversion module; the gate of the second N-type switch tube V02 is connected with 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 respectively; the second end of the ninth resistor R9 is connected with the anode of the second diode D2 and the input end of the IGBT driving circuit respectively.

[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 the gate voltage of the first N-type switch tube V01 is pulled low, so that the first N-type switch tube V01 is in the off state, thereby making the connection point between the second end of the fifth resistor R5 and the collector of the first N-type switch tube V01 high level. As a result, the fault feedback signal of high level is sent by the result feedback unit, and the fault feedback signal of high level 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 the off state, the gate voltage of the first N-type switch tube V01 remains high level, and the first N-type switch tube V01 is in the on state, thereby making the connection point between the second end of the fifth resistor R5 and the collector of the first N-type switch tube V01 low level. As a result, the fault feedback signal of low level is sent by the result feedback unit, and the fault feedback signal of low level is used to indicate that the IGBT is in a non-fault state.

[0086] According to some embodiments, the ninth resistor R9 can act 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 between 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 not normally on.

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

[0088] The first end of the fourth protection subunit is connected with 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 respectively, and the second end of the fourth protection subunit is connected with the first end of the eighth resistor.

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

[0090] According to some embodiments, as shown in Figure 2 The fourth protection subunit comprises a fifth diode D5; wherein,

[0091] The negative electrode of the fifth diode D5 is connected with 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 respectively, and the positive electrode of the fifth diode D5 is connected with the first end of the eighth resistor R8.

[0092] In some embodiments, by setting the fifth diode D5, the components in the multi-IGBT parallel fault detection circuit can be protected, overvoltage can be avoided, overvoltage energy in the circuit can be absorbed, and the reliability of the multi-IGBT parallel fault detection circuit can be improved.

[0093] Optionally, in one embodiment of the present disclosure, the components involved in the multi-IGBT parallel fault detection circuit can all adopt high-precision devices, so as to further improve the accuracy of IGBT fault detection.

[0094] In summary, the multi-IGBT parallel fault detection circuit provided by the embodiments of the present disclosure can monitor the state information in the multi-IGBT parallel operation process in real time, judge the health state of the IGBT device and the drive protection circuit, and provide feedback signals for the converter control protection device, so as to ensure the operation safety of the converter whole machine.

[0095] Furthermore, the word "exemplary" is used herein to mean serving as an example, instance, or illustration. Any aspect or design described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other aspects or designs. Rather, use of the word exemplary is intended to present concepts in a concrete manner. As used in this application, the term "or" is intended to mean an inclusive "or" rather than an exclusive "or". That is, unless specified otherwise, or clear from context, "X employs A or B" is intended to mean any of the natural inclusive permutations. That is, if X employs A; X employs B; or X employs both A and B, then "X employs A or B" is satisfied under any of the foregoing instances. In addition, the articles "a" and "an" as used in this application and the appended claims should generally be construed to mean "one or more" unless specified otherwise or clear from context to be directed to a singular form. Thus, use of the articles in this application and the following claims is not limiting.

[0096] Also, although the disclosure has been described and illustrated with respect to one or more implementations, the features can be used in various combinations of one or more features. It is not practical to illustrate all such combinations, but one of ordinary skill in the art will recognize that multiple features can be combined from different implementations. Such modifications and variations are considered to be within the scope of the present disclosure. The terms "comprise", "include", "have" and their conjugates, as used herein, have been used to enable the specification to fit a wide range of embodiments. The terms "comprise", "comprising", "include", "including", "have", "having" or variants thereof are used synonymously with each other in this disclosure and are intended to permit the inclusion of additional steps, features, components, elements, or steps without omitting or excluding other steps, features, components, elements, or steps described by the specification, claims or drawings. As used herein, the term "exemplary" is used in the sense of serving as an example, instance, or illustration. Any implementation described as "exemplary" is not necessarily to be construed as preferred or advantageous over other implementations.

[0097] Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the features disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the disclosure being indicated by the following claims.

[0098] It is to be understood that the disclosure is not limited to the precise construction described and as shown in the accompanying drawings, which will be subject to change based on factors such as manufacturing processes, material tolerances, and the like. The scope of the disclosure is limited only by the claims that follow.

Claims

1. A multi-IGBT parallel fault detection circuit, characterized by, The application relates to a fault detection module for an IGBT (Insulated Gate Bipolar Transistor) drive circuit. The fault detection module comprises a fault detection unit and a result feedback unit, the first end of the fault detection unit is connected with the positive direct current end of a plurality of IGBTs connected in parallel, the second end of the fault detection unit is connected with the second end of the result feedback unit and the input end of the IGBT drive circuit, and the third end of the fault detection unit is connected with the third end of the result feedback unit. The fault detection unit comprises a first resistor, a second resistor, a third resistor, a fourth resistor, a first capacitor, a second capacitor and a transient suppression diode. The 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 with the third end of the result feedback unit, the connection point between the second end of the first resistor and the second end of the first capacitor is used for receiving a first negative direct current power supply voltage, the negative electrode of the transient suppression diode is connected with 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 respectively, the second end of the second resistor is connected with the second end of the result feedback unit and the input end of the IGBT drive circuit respectively, the connection point between the second end of the third resistor and the second end of the second capacitor is used for receiving a second negative direct current power supply voltage, and the second end of the fourth resistor is connected with the positive direct current end of the plurality of IGBTs connected in parallel. When the plurality of IGBTs are in a fault state, the voltage corresponding to the 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 greater than a voltage threshold value. The IGBT drive circuit is used for receiving a driving signal and controlling the on-off state of the plurality of IGBTs according to the driving signal. The fault detection unit is used for detecting the fault of the plurality of IGBTs according to the voltage of the positive direct current end and the driving signal, and obtaining a fault detection result. The result feedback unit is used for sending a fault feedback signal corresponding to the fault detection result.

2. The multi-IGBT parallel fault detection circuit according to claim 1, characterized by, The fault detection unit further comprises a first protection subunit, a second protection subunit and a third protection subunit. The first end of the first protection subunit is connected with the negative electrode of the transient suppression diode, and the second end of the first protection subunit is connected with 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 respectively. The first end of the second protection subunit is connected with the second end of the second resistor, and the second end of the second protection subunit is connected with 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 with 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 for receiving a second negative direct current power supply voltage.

3. The multi-IGBT parallel fault detection circuit of claim 2, wherein, The first protection subunit comprises a first diode, the second protection subunit comprises a second diode, and the third protection subunit comprises a third diode. The negative electrode of the first diode is connected with the negative electrode of the transient suppression diode, and the positive electrode of the first diode is connected with 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 respectively; The negative electrode of the second diode is connected with the second end of the second resistor, and the positive electrode of the second diode is connected with the second end of the result feedback unit and the input end of the IGBT drive circuit respectively; The negative electrode of the third diode is connected with the second end of the third resistor, and the connection point between the positive electrode of the third diode and the second end of the second capacitor is used for receiving the second negative DC power voltage.

4. The multi-IGBT parallel fault detection circuit of claim 1, wherein, The fault detection unit further comprises a fourth diode; wherein The positive electrode of the fourth diode is connected with the second end of the fourth resistor, and the negative electrode of the fourth diode is connected with the positive DC end of the plurality of IGBTs connected in parallel.

5. The multi-IGBT parallel fault detection circuit of claim 1, wherein, The result feedback unit comprises 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 The connection point between the first end of the fifth resistor and the first end of the sixth resistor is used for receiving the first positive DC power voltage, the connection point between the second end of the fifth resistor and the collector of the first N-type switch tube is used for sending a fault feedback signal, the emitter of the first N-type switch tube is used for receiving a third negative DC power voltage, the gate of the first N-type switch tube is connected with 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 respectively, the gate of the second N-type switch tube is connected with the third end of the fault detection unit, the emitter of the second N-type switch tube is used for receiving a fourth negative DC power voltage, the connection point between the second end of the seventh resistor and the second end of the third capacitor is used for receiving a fifth negative DC power voltage, the connection point between the second end of the eighth resistor and the first end of the ninth resistor is used for receiving an initial drive signal, and the second end of the ninth resistor is connected with the second end of the fault detection unit and the input end of the IGBT drive circuit respectively.

6. The multi-IGBT parallel fault detection circuit of claim 5, wherein, The result feedback unit further comprises a fourth protection subunit; wherein The first end of the fourth protection subunit is connected with 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 respectively, and the second end of the fourth protection subunit is connected with the first end of the eighth resistor.

7. The multi-IGBT parallel fault detection circuit of claim 6, wherein, The fourth protection subunit comprises a fifth diode; wherein The negative electrode of the fifth diode is connected with 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 respectively, and the positive electrode of the fifth diode is connected with the first end of the eighth resistor.

8. The multi-IGBT parallel fault detection circuit of claim 5, wherein, The result feedback unit is configured to send a fault feedback signal corresponding to the fault detection result, and specifically configured to: When the voltage corresponding to the gate of the second N-type switch tube is greater than a voltage threshold, the second N-type switch tube is in a conducting state, the first N-type switch tube is in an off state, 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 a conducting state, 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.

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