An IGBT overcurrent protection circuit with fault latching function

Abstract

This invention discloses an IGBT overcurrent protection circuit with fault latching function, including an IGBT module, an IGBT driver module, a central control module, an overcurrent detection module, and an overcurrent latch module. The signal output terminal of the IGBT module is connected to the signal input terminal of the overcurrent detection module, the enable output terminal of the overcurrent detection module is connected to the enable input terminal of the IGBT driver module, the signal output terminal of the overcurrent detection module is connected to the signal input terminal of the overcurrent latch module, the signal output terminal of the overcurrent latch module is connected to the first data port of the central control module, the second data port of the central control module is connected to the signal input terminal of the IGBT driver module, and the signal output terminal of the IGBT driver module is connected to the signal input terminal of the IGBT module. This invention directly controls the IGBT driver module to turn off the IGBT module by the overcurrent detection module, and the overcurrent latch module connected to the overcurrent detection module sends a fault signal to the central control module, promptly notifying the central control module to disable the IGBT driver module and keep the IGBT module continuously on.

Description

Technical Field

[0001] This application relates to the field of overcurrent protection circuit technology, and in particular to an IGBT overcurrent protection circuit with fault self-locking function. Background Technology

[0002] In power control applications such as servo drives, frequency converters, and inverters, the inverter module, as the core carrier of power conversion, is of paramount importance in controlling failure rates and strengthening protection schemes. In practical applications, IGBT overcurrent due to overload or short circuit in three-phase UVW motors is the most common application failure. IGBT overcurrent protection design is indispensable. There are two main types of overcurrent technologies: one is the Vce saturation voltage drop detection method, which indirectly determines whether there is an overcurrent by detecting the IGBT conduction voltage drop; the other is the direct current detection method, which determines whether there is an overcurrent by detecting the actual current of the IGBT. Direct current detection is usually divided into two technical solutions: distributed current detection and concentrated current detection. Distributed current detection detects the three-phase current of UVW and uses hardware overcurrent threshold detection protection to shut down the IGBT in time. Concentrated current detection detects the bus current, and when the bus current exceeds the set value, all IGBTs are shut down simultaneously.

[0003] The existing centralized overcurrent detection circuit sends the overcurrent protection signal detected by the overcurrent detection module to the central control module, and then the central control module controls the IGBT drive module to turn off the IGBT control module. The disadvantage of this method is that the signal loop is large, and after an anomaly, the overcurrent signal needs to be sent back to the main control. It is difficult to realize the IGBT from overcurrent to turn-off in the microsecond time, resulting in a high failure rate of IGBT after overcurrent. Summary of the Invention

[0004] This invention proposes an IGBT overcurrent protection circuit with fault self-locking function. By having the overcurrent detection module directly control the IGBT drive module to shut down the IGBT control module, and the overcurrent latching module connected to the overcurrent detection module sends a fault signal to the central control module, the central control module is promptly notified to shut down the IGBT drive module and keep the IGBT control module on. This solves the problem of high IGBT fault rates after overcurrent due to large signal loops in existing centralized overcurrent detection circuits.

[0005] To achieve the above objectives, the present invention provides the following technical solution: an IGBT overcurrent protection circuit with fault self-locking function, comprising a power supply module, wherein the power output terminal of the power supply module outputs power to the protection circuit, the protection circuit comprising an IGBT control module, an IGBT drive module, a central control module, an overcurrent detection module, and an overcurrent latch module, wherein the signal input terminal of the overcurrent detection module is connected to the signal output terminal of the IGBT control module, the enable output terminal of the overcurrent detection module is connected to the enable input terminal of the IGBT drive module, the signal output terminal of the overcurrent detection module is connected to the signal input terminal of the overcurrent latch module, the signal output terminal of the overcurrent latch module is connected to the first data port of the central control module, the second data port of the central control module is connected to the signal input terminal of the IGBT drive module, and the signal output terminal of the IGBT drive module is connected to the signal input terminal of the IGBT control module.

[0006] As described above, an IGBT overcurrent protection circuit with fault self-locking function is provided. The IGBT control module includes a sampling module located on the bus of the IGBT control module. The sampling module includes a sampling resistor R13. The signal input terminal of the overcurrent detection module is connected to the sampling resistor R13 and samples the voltage across the sampling resistor R13.

[0007] As described above, an IGBT overcurrent protection circuit with fault-locking function includes an overcurrent detection module comprising a first amplifier circuit, an optocoupler OP3, resistors R17, R28, and R21, and a transistor Q1. The signal input terminal of the first amplifier circuit is connected to the signal output terminal of the sampling module, and the signal output terminal of the first amplifier circuit is connected to the signal input terminal of the optocoupler OP3. The enable output terminal of the optocoupler OP3 is connected to the first terminal of resistor R28, and the second terminal of resistor R28 is connected to the base of transistor Q1. The first terminal of resistor R17 is connected to the first power output terminal of the power module, and the second terminal of resistor R17 is connected to the first terminal of resistor R28. The first terminal of resistor R21 is connected to the first power output terminal of the power module, and the second terminal of resistor R21 is connected to the collector of transistor Q1. The emitter of transistor Q1 is grounded, and the second terminal of resistor R21 is the enable output terminal of the overcurrent detection module.

[0008] As described above, an IGBT overcurrent protection circuit with fault latching function includes an operational amplifier U3A, an operational amplifier U3B, resistors R22, R29, R30, R23, R27, R20, R19, diode D3, and Zener diode D4. The first terminal of resistor R22 is connected to the first terminal of sampling resistor R13, the first terminal of resistor R29 is connected to the second terminal of sampling resistor R13, the second terminal of resistor R22 is connected to the inverting input terminal of operational amplifier U3B, and the second terminal of resistor R29 is connected to the non-inverting input terminal of operational amplifier U3B. Resistor R30 is connected between the non-inverting input terminal of operational amplifier U3B and ground. The output terminal of operational amplifier U3B is connected to the first terminal of resistor R27, the second terminal of resistor R27 is connected to the inverting input terminal of operational amplifier U3A, the non-inverting input terminal of operational amplifier U3A is connected to the first terminal of resistor R23, the second power output terminal of the power module is connected to the second terminal of resistor R23, the first terminal of resistor R23 is connected to the positive terminal of diode D3, the negative terminal of diode D3 is connected to the first terminal of resistor R20, the second terminal of resistor R20 is connected to the negative terminal of Zener diode D4, the positive terminal of Zener diode D4 is connected to the first input terminal of optocoupler OP3, and the output terminal of operational amplifier U3A is connected to the second input terminal of optocoupler OP3.

[0009] As described above, an IGBT overcurrent protection circuit with fault latching function includes an overcurrent latching module comprising a second amplifier circuit, resistors R41, R42, and R46, and a transistor Q3. The signal input terminal of the second amplifier circuit is connected to the signal output terminal of the overcurrent detection module. The enable output terminal of the second amplifier circuit is connected to the first terminal of resistor R46. The second terminal of resistor R46 is connected to the base of transistor Q3. The first terminal of resistor R41 is connected to the first power output terminal of the power module. The second terminal of resistor R41 is connected to the first terminal of resistor R46. The first terminal of resistor R42 is connected to the first power output terminal of the power module. The second terminal of resistor R42 is connected to the collector of transistor Q3. The emitter of transistor Q3 is grounded. The second terminal of resistor R42 is the signal output terminal of the overcurrent latching module.

[0010] As described above, an IGBT overcurrent protection circuit with fault latching function includes a second amplification circuit comprising resistors R43, R38, R50, R45, R47, R48, R40, and R44, operational amplifiers U5A and U5B, and transistor Q2. The first end of resistor R43 is connected to the signal output terminal of the overcurrent detection module. Resistor R45 is connected between the second end of resistor R43 and the non-inverting input terminal of operational amplifier U5A. The inverting input terminal of operational amplifier U5A is connected between the common node of resistors R38 and R50. The other end of resistor R38 is connected to the power supply module... The first power output terminal is connected, the other end of the resistor R50 is grounded, the output terminal of the operational amplifier U5A is connected to the base of the transistor Q2, the first end of the resistor R40 is connected to the first power output terminal of the power module, the second end of the resistor R40 is connected to the emitter of the transistor Q2, the collector of the transistor Q2 is connected to the first end of the resistor R44, the second end of the resistor R44 is connected to the non-inverting input terminal of the operational amplifier U5B, the inverting input terminal of the operational amplifier U5B is connected to the second power output terminal of the power module, and the output terminal of the operational amplifier U5B is the enable output terminal of the second amplification circuit.

[0011] As described above, an IGBT overcurrent protection circuit with fault self-locking function includes an IGBT drive module comprising an isolation drive module and a level conversion module. The signal input terminal of the level conversion module is connected to the signal output terminal of the central control module, the signal output terminal of the level conversion module is connected to the signal input terminal of the isolation drive module, the enable output terminal of the isolation drive module is connected to the enable input terminal of the IGBT control module, and the signal output terminal of the isolation drive module is connected to the signal input terminal of the overcurrent detection module.

[0012] As described above, an IGBT overcurrent protection circuit with fault latching function includes an isolation drive module comprising resistors R35 and R36, diodes D6A and D6B, and an optocoupler OP5. The power input terminal of the optocoupler OP5 is connected to the first power output terminal of the power module. The power input terminal of the optocoupler OP5 is connected to the negative terminal of diode D6A. The positive terminal of diode D6A is the signal output terminal of the isolation drive module. The output terminal of the optocoupler OP5 is connected to the first terminal of resistor R36. The second terminal of resistor R36 is the signal output terminal of the isolation drive module. The second terminal of resistor R36 is connected to the positive terminal of diode D6B. The negative terminal of diode D6B is connected to the first terminal of resistor R35. The second terminal of resistor R35 is connected to the first terminal of resistor R36.

[0013] As described above, an IGBT overcurrent protection circuit with fault self-locking function includes a level conversion module comprising resistor R12, resistor R4, and level conversion chip U2. The first end of resistor R12 is connected to the data port of level conversion chip U2, and the second end of resistor R12 is connected to the second input terminal of optocoupler OP5. The first end of resistor R4 is connected to the data port of level conversion chip U2, and the second end of resistor R4 is connected to the first input terminal of optocoupler OP5. The enable input terminal of level conversion chip U2 is connected to the enable output terminal of the overcurrent detection module.

[0014] Compared with the prior art, this application has the following advantages:

[0015] This invention addresses the problem of high IGBT failure rates after overcurrent by having the overcurrent detection module directly control the IGBT drive module to shut down the IGBT control module, and the overcurrent latch module connected to the overcurrent detection module sends a fault signal to the central control module, thus promptly notifying the central control module to shut down the IGBT drive module and keep the IGBT control module on. This solves the problem of high IGBT failure rates after overcurrent caused by large signal loops in the centralized overcurrent detection circuits of the prior art. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below.

[0017] Figure 1 This is a circuit block diagram of the present invention;

[0018] Figure 2 This is the circuit diagram for the overcurrent detection module.

[0019] Figure 3 This is the circuit diagram of the overcurrent latch module.

[0020] Figure 4 This is the circuit diagram of the IGBT control module.

[0021] Figure 5 This is the circuit diagram for the level conversion module.

[0022] Figure 6 This is the circuit diagram of the isolated driver module.

[0023] Figure 7 It's the circuit of the central control module. Figure 1 ;

[0024] Figure 8 It's the circuit of the central control module. Figure 2 ;

[0025] Figure 9 It's the circuit of the central control module. Figure 3 ;

[0026] Figure 10 It's the circuit of the central control module. Figure 4 . Detailed Implementation

[0027] To make the technical problems solved, the technical solutions, and the beneficial effects of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0028] When ordinal numbers such as "first" and "second" are mentioned in the embodiments of the present invention, unless they actually express the meaning of order according to the context, they should be understood as being used only for differentiation.

[0029] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0030] like Figure 1-6 As shown, an IGBT overcurrent protection circuit with fault latching function includes a power supply module. The power output terminal of the power supply module outputs power to the protection circuit. The protection circuit includes an IGBT control module, an IGBT driver module, a central control module, an overcurrent detection module, and an overcurrent latch module. The signal input terminal of the overcurrent detection module is connected to the signal output terminal of the IGBT control module. The enable output terminal of the overcurrent detection module is connected to the enable input terminal of the IGBT driver module. The signal output terminal of the overcurrent detection module is connected to the signal input terminal of the overcurrent latch module. The signal output terminal of the overcurrent latch module is connected to the first data port of the central control module. The second data port of the central control module is connected to the signal input terminal of the IGBT driver module. The signal output terminal of the IGBT driver module is connected to the signal input terminal of the IGBT control module.

[0031] The power output terminals of the power module include a first power output terminal (i.e., +5V) and a second power output terminal (i.e., +2.5V).

[0032] In this embodiment, the present invention solves the problem of high IGBT failure rate after overcurrent due to large signal loop in the centralized overcurrent detection circuit of the prior art. This is achieved by having the overcurrent detection module directly control the IGBT drive module to turn off the IGBT control module, and the overcurrent latch module connected to the overcurrent detection module to send a fault signal to the central control module, so as to promptly notify the central control module to turn off the signal of the IGBT drive module and keep the IGBT control module on.

[0033] In this embodiment, the power supply module is also connected to a step-down module, which can reduce the power supply voltage to the 2.5V voltage required by the circuit chips. The IGBT control module is equipped with multiple IGBTs, which operate according to a certain pattern based on the circuit design.

[0034] Furthermore, the IGBT control module includes a sampling module located on the bus of the IGBT control module. The sampling module includes a sampling resistor R13. The signal input terminal of the overcurrent detection module is connected to the sampling resistor R13 and samples the voltage across the sampling resistor R13.

[0035] In this embodiment, the solution uses a sampling resistor R13 connected in series on the bus to calculate the current based on the voltage across the sampling resistor R13. The overcurrent triggering protection mechanism is implemented through hardware circuitry. The sampling resistor R13 is located at the end of the neutral line of the IGBT control module.

[0036] Furthermore, the overcurrent detection module includes a first amplifier circuit, an optocoupler OP3, resistors R17, R28, and R21, and a transistor Q1. The signal input terminal of the first amplifier circuit is connected to the signal output terminal of the sampling module, and the signal output terminal of the first amplifier circuit is connected to the signal input terminal of the optocoupler OP3. The enable output terminal of the optocoupler OP3 is connected to the first terminal of resistor R28, and the second terminal of resistor R28 is connected to the base of transistor Q1. The first terminal of resistor R17 is connected to the first power output terminal of the power module, and the second terminal of resistor R17 is connected to the first terminal of resistor R28. The first terminal of resistor R21 is connected to the first power output terminal of the power module, and the second terminal of resistor R21 is connected to the collector of transistor Q1. The emitter of transistor Q1 is grounded, and the second terminal of resistor R21 is the enable output terminal of the overcurrent detection module.

[0037] In this embodiment, the first amplifier circuit amplifies the voltage signal across the sampling resistor R13 to the required amplitude value, and then transmits the amplified voltage signal through the optocoupler OP3. The optocoupler OP3 acts as an isolation device, so that the signal interference caused by the first amplifier circuit does not affect the circuit after the optocoupler. The transistor Q1 acts as a switch. When the circuit experiences an overcurrent, the optocoupler OP3 turns on, thereby causing the base voltage of the transistor Q1 to reach the corresponding threshold, turning on the transistor Q1. The IGBT driver module receives the overcurrent signal and then turns off the IGBT control module.

[0038] Further, the first amplification circuit includes operational amplifier U3A, operational amplifier U3B, resistors R22, R29, R30, R23, R27, R20, R19, diode D3, and Zener diode D4. The first terminal of resistor R22 is connected to the first terminal of sampling resistor R13, the first terminal of resistor R29 is connected to the second terminal of sampling resistor R13, the second terminal of resistor R22 is connected to the inverting input terminal of operational amplifier U3B, and the second terminal of resistor R29 is connected to the non-inverting input terminal of operational amplifier U3B. Resistor R30 is connected between the non-inverting input terminal of operational amplifier U3B and ground. The output of operational amplifier U3B... The first terminal of the power supply module is connected to the first terminal of the resistor R27, the second terminal of the resistor R27 is connected to the inverting input terminal of the operational amplifier U3A, the non-inverting input terminal of the operational amplifier U3A is connected to the first terminal of the resistor R23, the second power output terminal of the power supply module is connected to the second terminal of the resistor R23, the first terminal of the resistor R23 is connected to the positive terminal of the diode D3, the negative terminal of the diode D3 is connected to the first terminal of the resistor R20, the second terminal of the resistor R20 is connected to the negative terminal of the Zener diode D4, the positive terminal of the Zener diode D4 is connected to the first input terminal of the optocoupler OP3, and the output terminal of the operational amplifier U3A is connected to the second input terminal of the optocoupler OP3.

[0039] In this embodiment, resistors R22 and R29 are balancing resistors in operational amplifier U3B, and resistors R23 and R27 are balancing resistors in operational amplifier U3A. They are used to balance the offset current of the two input terminals of the operational amplifier, so that the voltage of the two terminals is balanced. Resistor R30 is a pull-down resistor, and resistor R19 is a pull-up resistor. The high potential flows from diode D3 to resistor R20, then to Zener diode D4, and finally to the positive terminal of the LED of optocoupler OP3. At the same time, this line will also form a self-loop circuit with operational amplifier U3A, making the switching of operational amplifier U3A more stable. At this time, if an overcurrent signal is generated, after being amplified by operational amplifier U3B, operational amplifier U3A receives the amplified signal and flips the output terminal of operational amplifier U3A to a low potential, which flows to the negative terminal of the LED of optocoupler OP3, forming a potential difference that turns on the LED.

[0040] Furthermore, the overcurrent latch module includes a second amplifier circuit, resistors R41, R42, and R46, and a transistor Q3. The signal input terminal of the second amplifier circuit is connected to the signal output terminal of the overcurrent detection module. The enable output terminal of the second amplifier circuit is connected to the first terminal of resistor R46. The second terminal of resistor R46 is connected to the base of transistor Q3. The first terminal of resistor R41 is connected to the first power output terminal of the power module. The second terminal of resistor R41 is connected to the first terminal of resistor R46. The first terminal of resistor R42 is connected to the first power output terminal of the power module. The second terminal of resistor R42 is connected to the collector of transistor Q3. The emitter of transistor Q3 is grounded. The second terminal of resistor R42 is the signal output terminal of the overcurrent latch module.

[0041] In this embodiment, the second amplification circuit amplifies the fault notification signal output by the overcurrent detection module to the required amplitude value, so that the base voltage of transistor Q1 reaches the corresponding threshold, causing transistor Q1 to conduct. The central control module receives the fault notification signal and then turns off the IGBT drive module and turns on the drive signal of the IGBT control module. Resistor R46 acts as a voltage divider, resistor R42 acts as a current limiter, and resistor R41 is a pull-up resistor.

[0042] Further, the second amplification circuit includes resistors R43, R38, R50, R45, R47, R48, R40, and R44, operational amplifiers U5A and U5B, and transistor Q2. The first end of resistor R43 is connected to the signal output terminal of the overcurrent detection module. Resistor R45 is connected between the second end of resistor R43 and the non-inverting input terminal of operational amplifier U5A. The inverting input terminal of operational amplifier U5A is connected between the common node of resistors R38 and R50. The other end of resistor R38 is connected to the first power output terminal of the power supply module. The other end of resistor R50 is grounded. Resistor R48 is connected between the output terminal of operational amplifier U5A and the base of transistor Q2. The first end of resistor R40 is connected to the first power output terminal of the power module. The second end of resistor R40 is connected to the emitter of transistor Q2. The collector of transistor Q2 is connected to the first end of resistor R44. The second end of resistor R44 is connected to the non-inverting input terminal of operational amplifier U5B. The inverting input terminal of operational amplifier U5B is connected to the second power output terminal of the power module. The output terminal of operational amplifier U5B is the enable output terminal of the second amplification circuit.

[0043] In this embodiment, resistors R38 and R50 form a voltage sampling network, ensuring that the inverting input of operational amplifier U5A reaches the corresponding voltage amplitude, i.e., 2.5V. Resistors R45 and R47 are the balancing resistors for operational amplifier U5A, and resistor R48 acts as a voltage divider, ensuring that the base voltage of transistor Q2 reaches the set threshold, causing the output of operational amplifier U5B to also output a corresponding voltage signal. This, in turn, causes the base voltage of transistor Q3 to reach the threshold and conduct, allowing the central control module to receive the fault notification signal.

[0044] Furthermore, the IGBT drive module includes an isolation drive module and a level conversion module. The signal input terminal of the level conversion module is connected to the signal output terminal of the central control module, the signal output terminal of the level conversion module is connected to the signal input terminal of the isolation drive module, the enable output terminal of the isolation drive module is connected to the enable input terminal of the IGBT control module, and the signal output terminal of the isolation drive module is connected to the signal input terminal of the overcurrent detection module.

[0045] In this embodiment, the isolation driver module is unaffected by signal interference generated by the level conversion module.

[0046] Furthermore, the isolation drive module includes resistors R35 and R36, diodes D6A and D6B, and optocoupler OP5. The power input terminal of optocoupler OP5 is connected to the first power output terminal of the power module. The power input terminal of optocoupler OP5 is connected to the negative terminal of diode D6A. The positive terminal of diode D6A is the signal output terminal of the isolation drive module. The output terminal of optocoupler OP5 is connected to the first terminal of resistor R36. The second terminal of resistor R36 is the signal output terminal of the isolation drive module. The second terminal of resistor R36 is connected to the positive terminal of diode D6B. The negative terminal of diode D6B is connected to the first terminal of resistor R35. The second terminal of resistor R35 is connected to the first terminal of resistor R36.

[0047] In this embodiment, the function of diode D6A is to prevent the drive level from being too high and to clamp the voltage at 15V. Diode D6B is used to make the impedance different when it is turned off and turned on. When it is turned on, only the impedance of resistor R36 is needed, while when it is turned off, the impedance of resistors R36 and R35 is needed to consume the impedance. When the drive level is too high when it is turned off, it can consume the drive level and make it slowly decrease until it disappears.

[0048] Furthermore, the level conversion module includes resistor R12, resistor R4, and level conversion chip U2. The first end of resistor R12 is connected to the data port of level conversion chip U2, and the second end of resistor R12 is connected to the second input terminal of optocoupler OP5. The first end of resistor R4 is connected to the data port of level conversion chip U2, and the second end of resistor R4 is connected to the first input terminal of optocoupler OP5. The enable input terminal of level conversion chip U2 is connected to the enable output terminal of overcurrent detection module.

[0049] In this embodiment, resistors R12 and R4 serve to limit current.

[0050] More preferably, such as Figure 7-10 As shown, the central control module is divided into two parts: the first control board and the second control board. The first control board sends out 6 control signals to control the IGBT drive module. The overcurrent latch module feeds back the fault notification to the second control board. The second control board processes the data and then controls the first control board.

[0051] The working principle of this invention is as follows:

[0052] This invention detects the level signal of the sampling module through an overcurrent detection module. Then, the overcurrent detection module directly controls the IGBT driver module to shut down the IGBT control module. Furthermore, an overcurrent latch module connected to the overcurrent detection module sends a fault signal to the central control module, promptly notifying the central control module to turn off the IGBT driver module and keep the IGBT control module on. The overcurrent detection module includes a first amplifier circuit and a transistor. The first amplifier circuit amplifies the voltage signal across the sampling module to the required amplitude, turning on transistor Q1, and then sending an enable signal to the IGBT driver module to turn off the IGBT control module. The overcurrent latch module includes a second amplifier circuit and a transistor Q3. It then amplifies the level signal generated by the overcurrent detection module, turning on transistor Q3, and then sending a signal to the central control module to turn off the IGBT driver module and keep the IGBT control module on.

[0053] The above description is one implementation method provided in conjunction with specific content, and does not imply that the specific implementation of this application is limited to these descriptions. Any methods or structures that are similar to or identical to those of this application, or any technical deductions or substitutions made based on the concept of this application, should be considered within the scope of protection of this application.

Claims

1. An IGBT overcurrent protection circuit with fault self-locking function, comprising a power supply module, wherein the power supply module outputs power to the protection circuit, characterized in that, The protection circuit includes an IGBT control module, an IGBT driver module, a central control module, an overcurrent detection module, and an overcurrent latch module. The signal input terminal of the overcurrent detection module is connected to the signal output terminal of the IGBT control module, the enable output terminal of the overcurrent detection module is connected to the enable input terminal of the IGBT driver module, the signal output terminal of the overcurrent detection module is connected to the signal input terminal of the overcurrent latch module, the signal output terminal of the overcurrent latch module is connected to the first data port of the central control module, the second data port of the central control module is connected to the signal input terminal of the IGBT driver module, and the signal output terminal of the IGBT driver module is connected to the signal input terminal of the IGBT control module. The IGBT control module includes a sampling module located on the bus of the IGBT control module. The sampling module includes a sampling resistor R13. The signal input terminal of the overcurrent detection module is connected to the sampling resistor R13 and samples the voltage across the sampling resistor R13. The overcurrent detection module includes a first amplifier circuit, an optocoupler OP3, resistors R17, R28, and R21, and a transistor Q1. The signal input terminal of the first amplifier circuit is connected to the signal output terminal of the sampling module, and the signal output terminal of the first amplifier circuit is connected to the signal input terminal of the optocoupler OP3. The enable output terminal of the optocoupler OP3 is connected to the first terminal of resistor R28, and the second terminal of resistor R28 is connected to the base of transistor Q1. The first terminal of resistor R17 is connected to the first power output terminal of the power module, and the second terminal of resistor R17 is connected to the first terminal of resistor R28. The first terminal of resistor R21 is connected to the first power output terminal of the power module, and the second terminal of resistor R21 is connected to the collector of transistor Q1. The emitter of transistor Q1 is grounded, and the second terminal of resistor R21 is the enable output terminal of the overcurrent detection module. The first amplification circuit includes operational amplifier U3A, operational amplifier U3B, resistors R22, R29, R30, R23, R27, R20, R19, diode D3, and Zener diode D4. The first terminal of resistor R22 is connected to the first terminal of sampling resistor R13, the first terminal of resistor R29 is connected to the second terminal of sampling resistor R13, the second terminal of resistor R22 is connected to the inverting input terminal of operational amplifier U3B, and the second terminal of resistor R29 is connected to the non-inverting input terminal of operational amplifier U3B. Resistor R30 is connected between the non-inverting input terminal of operational amplifier U3B and ground. The output terminal of operational amplifier U3B is connected to... The first end of resistor R27 is connected to the first terminal of the second terminal of the first terminal of the second terminal of the first terminal of the second terminal of the first terminal of the second terminal of the second terminal of the first terminal of the second terminal of the second terminal of the second terminal of the first terminal of the second terminal of the second terminal of the first terminal of the second terminal of the second terminal of the second terminal of the first terminal of the second terminal of the second terminal of the first terminal of the second terminal of the second terminal of the first terminal of the second terminal of the second terminal of the first terminal of the second terminal of the first terminal of the second terminal of the first terminal of the second terminal of the first terminal of the second terminal of the second terminal of the first terminal of the second terminal of the second terminal of the first terminal of the second terminal of the second terminal of the second terminal of the first terminal of the second terminal of the second terminal of the second terminal of the second terminal of the second terminal of the second terminal of the second terminal of the second terminal of the second terminal of the second terminal of the second terminal of the second terminal of the second terminal of the second terminal of the second terminal of the second terminal of the second terminal of the third ... The overcurrent latch module includes a second amplifier circuit, resistors R41, R42, and R46, and a transistor Q3. The signal input terminal of the second amplifier circuit is connected to the signal output terminal of the overcurrent detection module. The enable output terminal of the second amplifier circuit is connected to the first terminal of resistor R46. The second terminal of resistor R46 is connected to the base of transistor Q3. The first terminal of resistor R41 is connected to the first power output terminal of the power module. The second terminal of resistor R41 is connected to the first terminal of resistor R46. The first terminal of resistor R42 is connected to the first power output terminal of the power module. The second terminal of resistor R42 is connected to the emitter of transistor Q3. The collector of transistor Q3 is grounded. The second terminal of resistor R42 is the signal output terminal of the overcurrent latch module. The second amplification circuit includes resistors R43, R38, R50, R45, R47, R48, R40, and R44, operational amplifiers U5A and U5B, and transistor Q2. The first end of resistor R43 is connected to the signal output terminal of the overcurrent detection module. Resistor R45 is connected between the second end of resistor R43 and the non-inverting input terminal of operational amplifier U5A. The inverting input terminal of operational amplifier U5A is connected between the common node of resistors R38 and R50. The other end of resistor R38 is connected to the first power output terminal of the power supply module. The other end of resistor R50 is grounded. Resistor R48 is connected between the output terminal of operational amplifier U5A and the base of transistor Q2. The first end of resistor R40 is connected to the first power output terminal of the power module. The second end of resistor R40 is connected to the emitter of transistor Q2. The collector of transistor Q2 is connected to the first end of resistor R44. The second end of resistor R44 is connected to the non-inverting input terminal of operational amplifier U5B. The inverting input terminal of operational amplifier U5B is connected to the second power output terminal of the power module. The output terminal of operational amplifier U5B is the enable output terminal of the second amplification circuit.

2. The IGBT overcurrent protection circuit with fault self-locking function according to claim 1, characterized in that, The IGBT drive module includes an isolation drive module and a level conversion module. The signal input terminal of the level conversion module is connected to the signal output terminal of the central control module, the signal output terminal of the level conversion module is connected to the signal input terminal of the isolation drive module, the enable output terminal of the isolation drive module is connected to the enable input terminal of the IGBT control module, and the signal output terminal of the isolation drive module is connected to the signal input terminal of the overcurrent detection module.

3. The IGBT overcurrent protection circuit with fault self-locking function according to claim 2, characterized in that, The isolation drive module includes resistors R35 and R36, diodes D6A and D6B, and optocoupler OP5. The power input terminal of optocoupler OP5 is connected to the first power output terminal of the power module. The power input terminal of optocoupler OP5 is connected to the negative terminal of diode D6A. The positive terminal of diode D6A is the signal output terminal of the isolation drive module. The output terminal of optocoupler OP5 is connected to the first terminal of resistor R36. The second terminal of resistor R36 is the signal output terminal of the isolation drive module. The second terminal of resistor R36 is connected to the positive terminal of diode D6B. The negative terminal of diode D6B is connected to the first terminal of resistor R35. The second terminal of resistor R35 is connected to the first terminal of resistor R36.

4. The IGBT overcurrent protection circuit with fault self-locking function according to claim 3, characterized in that, The level conversion module includes resistors R12 and R4 and a level conversion chip U2. The first end of resistor R12 is connected to the data port of the level conversion chip U2, and the second end of resistor R12 is connected to the second input terminal of the optocoupler OP5. The first end of resistor R4 is connected to the data port of the level conversion chip U2, and the second end of resistor R4 is connected to the first input terminal of the optocoupler OP5. The enable input terminal of the level conversion chip U2 is connected to the enable output terminal of the overcurrent detection module.

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