An igbt current rate peak extraction circuit, system and method

Abstract

The application discloses an IGBT current rate peak extraction circuit, system and method, and the peak circuit comprises: a positive value translation circuit, which is used for shifting downward the detection waveform of the change rate of the power device switching transient current when the power device switching transient current drops; a negative value translation flip circuit, which is used for flipping and shifting downward the detection waveform of the change rate of the power device switching transient current when the power device switching transient current rises; a rectification amplification circuit, which is used for amplifying the voltage waveform at the peak after the treatment of the positive value translation circuit or the negative value translation flip circuit; a peak holding circuit, which is used for extracting and maintaining the maximum value of the voltage waveform; and an RC discharge equivalent circuit, which is used for equivalently discharging the extracted peak in the form of a capacitor-resistor discharge time. The application can extract the switching transient current change rate in real time, and is helpful to the online health analysis of the power module and the diode.

Description

Technical Field

[0001] The present invention belongs to the technical field of power electronics, and in particular relates to an IGBT current rate peak extraction circuit, system and method. Background Art

[0002] As the performance of high-power conversion systems continues to improve, the reliability requirements for core power semiconductor devices, IGBTs, are also increasing. This has led to the development of IGBT condition monitoring technologies. Extracting health-sensitive electrical parameter characteristics during IGBT switching transients is a relatively novel approach that can be used for online analysis of IGBT health status issues, including switching trajectory, operating junction temperature, aging, and EMI. The maximum current rate of change during switching transients has excellent correlation with health status. However, current research is limited to characteristic analysis, and further research is needed on circuits for extracting the peak value of the current rate of change waveform. Due to the small variation range of health-sensitive electrical parameters, the difference in the peak current rate of change between different health states accounts for a very small proportion of the entire waveform, making it difficult for extraction circuits to distinguish within their power supply range. During IGBT switching transients, the current rate of change needs to be extracted for both positive and negative directions, requiring separate extraction. This increases the complexity of the extraction circuitry. Furthermore, the extracted peak values ​​are often transmitted to digital chips via ADCs for identification, increasing circuit cost. Summary of the Invention

[0003] The purpose of the embodiments of the present invention is to provide an IGBT current rate peak extraction circuit, system and method to solve the above technical problems.

[0004] In a first aspect, the present invention discloses an IGBT current rate peak extraction circuit, the peak circuit comprising:

[0005] A positive shift circuit is used to shift downward the detection waveform of the rate of change of the transient current of the power device switch when it decreases;

[0006] A negative shift flip circuit is used to flip the detection waveform of the rate of change of the transient current of the power device switch when it rises, and shift it downward;

[0007] A rectifier amplifier circuit is used to extract and amplify the voltage waveform of the portion greater than zero after being processed by the positive shift circuit or the negative shift flip circuit;

[0008] Peak hold circuit, used to extract the peak value of the voltage waveform and maintain the maximum value;

[0009] The RC discharge equivalent circuit is used to convert the extracted peak value into the equivalent value of the capacitor and resistor discharge time.

[0010] In an embodiment, the positive value translation circuit comprises resistor R1, resistor R2, operational amplifier OP1, analog switch S W1 ; one end of the resistor R1 is connected with the resistor R2 and the negative input terminal of the operational amplifier OP1; the positive input terminal of the operational amplifier OP1 is connected with reference voltage V r1 ; the output terminal of the operational amplifier OP1 is connected with the other end of the resistor R2 and one end of the analog switch S W1 .

[0011] In an embodiment, the negative value translation inversion circuit comprises resistor R3, resistor R4, resistor R5, resistor R6, operational amplifier OP2, analog switch S W2 ; one end of the R3 is connected with the other end of the resistor R1 and the current change rate extraction voltage V DIDT ; the other end of the R3 is connected with one end of the R4 and the positive input terminal of the operational amplifier OP2; the other end of the R4 is grounded; one end of the R5 is connected with the reference voltage V r2 ; the other end of the R5 is connected with the negative input terminal of the operational amplifier OP2 and one end of the R6; the other end of the R6 is connected with the output terminal of the operational amplifier OP2 and one end of the analog switch S W2 ; the other end of the analog switch S W2 is connected with the other end of the analog switch S W1 , and outputs node voltage V1.

[0012] In an embodiment, the rectification amplification circuit comprises diode D1, diode D2, resistor R7, resistor R8 and operational amplifier OP3; the anode of the diode D1 receives node voltage V1; the cathode of the diode D1 is connected with the cathode of the diode D2 and the positive input terminal of the operational amplifier OP3; the anode of the diode D2 is grounded, one end of the resistor R7 is connected with one end of the resistor R8 and the negative input terminal of the operational amplifier OP3; the other end of the resistor R7 is grounded; the output terminal of the operational amplifier OP3 is connected with the other end of the resistor R8, and outputs node voltage V2.

[0013] In an embodiment, the peak value holding circuit comprises transconductance operational amplifier OT1, diode D3 and capacitor C1; the positive input terminal of the transconductance operational amplifier OT1 receives node voltage V2; the output terminal of the transconductance operational amplifier OT1 is connected with the anode of the diode D3; the negative input terminal of the transconductance operational amplifier OT1 is connected with the cathode of the diode D3 and one end of the capacitor C1, and outputs node voltage V3; the other end of the capacitor C1 is grounded.

[0014] In an embodiment, the RC discharge equivalent circuit comprises resistor R9, analog switch S W3 and comparator CP1; one end of the resistor R9 is connected with the negative input terminal of the comparator CP1 and receives node voltage V3; the other end of the resistor R9 is connected with the analog switch SW3 one end; the other end of the analog switch S W3 is grounded; the positive input end of the comparator CP1 is connected with a reference voltage V REF ; the output signal V PK of the comparator CP1 is connected with the other end of the analog switch S

[0015] The second invention discloses an IGBT current rate peak extraction system, which comprises:

[0016] The TGBT current rate peak extraction circuit is used for extracting the maximum change rate peak value of the IGBT current.

[0017] The digital control unit is used for controlling the maximum change rate peak value circuit of the IGBT current according to the received IGBT switching signal, and generating a regulation signal for controlling the turn-on and turn-off of the IGBT according to the received IGBT switching signal and the maximum change rate peak value of the IGBT.

[0018] The adjustable gate amplifier is used for adjusting the turn-on and turn-off rate of the IGBT according to the regulation signal output by the digital control unit.

[0019] In an embodiment, the rate peak value comprises an IGBT turn-on transient current rise rate peak value, an IGBT turn-off transient current drop rate peak value and an IGBT anti-parallel diode reverse recovery current change rate peak value.

[0020] In an embodiment, the digital control unit controls the maximum change rate peak value circuit of the IGBT current according to the received IGBT switching signal, specifically comprising:

[0021] When the digital control unit receives a PWM pulse of the turn-on signal, the adjustable gate amplifier turns on the IGBT, the V SW1 signal closes the S W1 , the V SW2 signal opens the S W2 , and the negative value translation inverting circuit converts the part of the voltage signal V DIDT close to the peak value into a positive value and the rest into a negative value, and outputs a signal V1 for extracting the IGBT turn-on transient current rise rate peak value.

[0022] When the digital control unit receives a PWM pulse of the turn-off signal, the adjustable gate amplifier turns off the IGBT, the V SW2 signal closes the S W2 , the V SW1 signal opens the S W1 , and the positive value translation circuit converts the part of the voltage signal V DIDTThe part close to the peak value keeps positive, and the rest part keeps negative, and the output signal V1 is used for extracting the peak value of the IGBT reverse recovery current change rate.

[0023] When the IGBT keeps in the off state, S W2 Keeps in the closed state, S W1 Keeps in the open state, when the current fluctuation occurs, the positive value translation circuit shifts the voltage signal V DIDT The part close to the peak value keeps positive, and the rest part keeps negative, and the output signal V1 is used for extracting the peak value of the IGBT reverse recovery current change rate.

[0024] In a third aspect, the application discloses an IGBT current rate peak value extraction method, and the method comprises the following steps:

[0025] The TGBT current rate peak value extraction circuit extracts the maximum change rate peak value of the IGBT current.

[0026] According to the received IGBT switching signal and the maximum change rate peak value of the IGBT current, the turn-on and turn-off rates of the IGBT are adjusted.

[0027] According to the received IGBT switching signal, the IGBT maximum change rate peak value circuit is controlled to work.

[0028] The application has the following beneficial effects:

[0029] The application can extract the maximum current rising rate and the maximum reverse recovery current falling rate in the power device turn-on transient state and the maximum current falling rate in the turn-off transient state, can amplify the difference between the current change rates of the IGBT and the anti-parallel diode in different working states, improve the diagnosis ability of the driving to the working state, and can extract the switching transient current change rate in real time, which is helpful for the online health analysis of the power module and the diode. DETAILED DESCRIPTION

[0030] The accompanying drawings, which are part of the present application, serve to provide a further understanding of the application, and the illustrative embodiments of the present application and their descriptions serve to explain the present application but do not constitute improper limitations on the present application. Obviously, the accompanying drawings in the following description are only some embodiments, and other drawings can be obtained from these drawings without creative labor for those skilled in the art.

[0031] Figure 1 The IGBT current rate peak value extraction circuit connection block diagram provided by an embodiment of the application;

[0032] Figure 2 The IGBT current rate peak value extraction circuit principle diagram provided by an embodiment of the application;

[0033] Figure 3 The IGBT current rate peak extraction system connection block diagram provided by an embodiment of the present application.

[0034] It should be noted that the drawings and the written description are not intended to limit the scope of the present application in any way, but are merely to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0035] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the drawings. The embodiments described below by referring to the drawings are exemplary and are used only to explain the present application, and cannot be interpreted as limiting the present application.

[0036] It should be clear that the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0037] The optional embodiments of the present disclosure are described in detail below with reference to the drawings.

[0038] Referring to Figure 1 , the present application provides an IGBT current rate peak extraction circuit based on, the peak circuit comprising: a positive value translation circuit, a negative value translation flip circuit, a rectification amplification circuit, a peak holding circuit and an RC discharge equivalent circuit,

[0039] The positive value translation circuit is used to shift the detection waveform of the change rate of the power device switching transient current downward when it decreases;

[0040] The negative value translation flip circuit is used to flip and shift the detection waveform of the change rate of the power device switching transient current downward when it rises;

[0041] The rectification amplification circuit is used to extract and amplify the voltage waveform greater than zero after being processed by the positive value translation circuit or the negative value translation flip circuit;

[0042] The peak holding circuit is used to extract and maintain the maximum value of the voltage waveform;

[0043] The RC discharge equivalent circuit is used to equivalently discharge the extracted peak value in the form of capacitor resistance discharge time.

[0044] Figure 2 A IGBT current rate peak extraction circuit schematic diagram provided by an embodiment of the present application is shown below, and the specific connection relationship of the components of the IGBT current rate peak extraction circuit is described in detail.

[0045] The positive value translation circuit is used to translate the detection waveform of the change rate of the power device switching transient current downward. Its purpose is to make the detection waveform close to the peak part greater than zero and the rest part less than zero. The positive value translation circuit comprises: a resistor R1, a resistor R2, an operational amplifier OP1, and an analog switch S W1 ; one end of the resistor R1 is connected with the resistor R2 and the negative input end of the operational amplifier OP1; the positive input end of the operational amplifier OP1 is connected with a reference voltage V r1 ; the output end of the operational amplifier OP1 is connected with the other end of the resistor R2 and one end of the analog switch S W1 .

[0046] The negative value translation and inversion circuit is used to invert and translate downward the detection waveform of the change rate of the power device switching transient current when rising. Its purpose is to make the detection waveform close to the peak part greater than zero and the rest part less than zero. The negative value translation and inversion circuit comprises: a resistor R3, a resistor R4, a resistor R5, a resistor R6, an operational amplifier OP2, and an analog switch S W2 ; one end of the resistor R3 is connected with the other end of the resistor R1 and a current change rate extraction voltage V DIDT ; the other end of the resistor R3 is connected with one end of the resistor R4 and the positive input end of the operational amplifier OP2; the other end of the resistor R4 is grounded; one end of the resistor R5 is connected with a reference voltage V r2 ; the other end of the resistor R5 is connected with the negative input end of the operational amplifier OP2 and one end of the resistor R6; the other end of the resistor R6 is connected with the output end of the operational amplifier OP2, one end of the analog switch S W2 , and the other end of the analog switch S W2 is connected with the other end of the analog switch S W1 , and outputs a node voltage V1.

[0047] The rectification and amplification circuit is used to extract a voltage waveform greater than zero and amplify the voltage waveform, so that when the peak value of the current change rate caused by the change of the IGBT working state changes, the extracted peak voltage difference is expanded, and comprises: a diode D1, a diode D2, a resistor R7, a resistor R8, and an operational amplifier OP3; the anode of the diode D1 receives a node voltage V1; the cathode of the diode D1 is connected with the cathode of the diode D2 and the positive input end of the operational amplifier OP3; the anode of the diode D2 is grounded, one end of the resistor R7 is connected with one end of the resistor R8 and the negative input end of the operational amplifier OP3; the other end of the resistor R7 is grounded; the output end of the operational amplifier OP3 is connected with the other end of the resistor R8, and outputs a node voltage V2.

[0048] The peak holding circuit is used for extracting and maintaining the peak value of the input voltage waveform, comprising a transconductance operational amplifier OT1, a diode D3, a capacitor C1, and the positive input end of the transconductance operational amplifier OT1 receiving a node voltage V2; the output end of the transconductance operational amplifier OT1 is connected with the anode of the diode D3; the negative input end of the transconductance operational amplifier OT1 is connected with the cathode of the diode D3 and one end of the capacitor C1, and outputs a node voltage V3; the other end of the capacitor C1 is grounded.

[0049] The RC discharge equivalent circuit is used for equivalently discharging the extracted peak value in the form of capacitor-resistor discharge time, comprising a resistor R9, an analog switch S W3 , and a comparator CP1; one end of the resistor R9 is connected with the negative input end of the comparator CP1 and receives the node voltage V3; the other end of the resistor R9 is connected with one end of the analog switch S W3 ; the other end of the analog switch S W3 is grounded; the positive input end of the comparator CP1 is connected with a reference voltage V REF ; and the comparator CP1 outputs a signal V PK .

[0050] In the RC discharge equivalent circuit, when the signal V3 rises to be higher than the reference voltage V REF , the signal V PK changes from high level to low level, the digital control unit recognizes that the IGBT current starts to change, after a waiting time ensuring that V3 reaches the peak value, the signal V SW3 closes the analog switch S W3 , and sets the time as t1, C1 discharges, V3 drops, and until V3 is lower than the reference voltage V REF , the signal V PK changes from low level to high level, and sets the time as t2, and the time period△t from t1 to t2 can be equivalent to the peak value.

[0051] It should be noted that the above embodiments are only exemplary embodiments for illustrating the principles of the present application, and the present application is not limited thereto.

[0052] Referring to Figure 3 , it shows a connection block diagram of an IGBT current rate peak extraction system provided by one exemplary embodiment of the present application. The IGBT current rate peak extraction system can be realized as all or part of a terminal by software, hardware or a combination of both. The system comprises:

[0053] The IGBT current rate peak extraction circuit is used for extracting the maximum change rate peak value of the IGBT current;

[0054] The digital control unit is used to control the operation of the maximum change rate peak circuit of the IGBT current according to the received IGBT switching signal, and to generate a regulating signal for controlling the on and off of the IGBT according to the received IGBT switching signal and the maximum change rate peak of the IGBT;

[0055] The adjustable gate amplifier is used to adjust the turn-on and turn-off rates of the IGBT according to the adjustment signal output by the digital control unit.

[0056] Furthermore, the rate peaks include the IGBT turn-on transient current rise rate peak, the IGBT turn-off transient current drop rate peak, and the IGBT anti-parallel diode reverse recovery current change rate peak.

[0057] Specifically, in different switching states of the IGBT, the IGBT current rate peak extraction circuit detects the peak value of the IGBT turn-on transient current rising rate, the peak value of the IGBT turn-off transient current falling rate and the peak value of the IGBT anti-parallel diode reverse recovery current change rate, where the IGBT turn-on transient current rises in the positive direction and the current change rate dI C / dt is positive, the voltage signal V induced by the parasitic inductance LS DIDT When the IGBT is turned off, the transient current drops and the reverse recovery current of the anti-parallel diode changes in the negative direction. The current change rate dI C / dt is negative, the voltage signal V induced by the parasitic inductance LS DIDT is a positive value, V DIDT With dI C The relationship between / dt is:

[0058]

[0059] In this application, the circuit operation of controlling the maximum rate of change of the IGBT current according to the received IGBT switching signal specifically includes:

[0060] When the digital control unit receives the PWM pulse of the turn-on signal, the adjustable gate amplifier turns on the IGBT, V SW1 The signal will S W1 Closed, V SW2 The signal will S W2 Disconnect, the negative shift flip circuit will turn the voltage signal V DIDT The part close to the peak value is converted to a positive value, and the rest is negative. The output signal V1 is used to extract the peak value of the transient current rise rate when the IGBT is turned on;

[0061] When the digital control unit receives the PWM pulse of the shutdown signal, the adjustable gate amplifier turns off the IGBT, V SW2 The signal will S W2 Closed, VSW1 signal S will be closed W1 signal S will be closed DIDT The part close to the peak value is kept as positive value, and the rest is negative value, and the output signal V1 is used for extracting the peak value of the IGBT turn-off transient current falling rate.

[0062] When the IGBT keeps in the turn-off state, signal S will be closed W2 signal S will be closed W1 signal S will be closed, and when the current fluctuation occurs, the positive value translation circuit will translate the voltage signal V DIDT The part close to the peak value is kept as positive value, and the rest is negative value, and the output signal V1 is used for extracting the peak value of the IGBT anti-parallel diode reverse recovery current change rate.

[0063] Specifically, when the digital control unit receives the PWM pulse of the turn-on signal, the adjustable gate amplifier turns on the IGBT, and signal S will be closed SW1 signal S will be closed W1 signal S will be closed SW2 signal S will be closed W2 signal S will be closed, and the negative value translation inverting circuit will translate the voltage signal V DIDT The part close to the peak value is converted to positive value, and the rest is negative value, and the output signal V1 is used for extracting the peak value of the IGBT turn-on transient current rising rate; the output voltage V1 is:

[0064]

[0065] When the digital control unit receives the PWM pulse of the turn-off signal, the adjustable gate amplifier turns off the IGBT, and signal S will be closed SW2 signal S will be closed W2 signal S will be closed SW1 signal S will be closed W1 signal S will be closed, and the positive value translation circuit will translate the voltage signal V DIDT The part close to the peak value is kept as positive value, and the rest is negative value, and the output signal V1 is used for extracting the peak value of the IGBT turn-off transient current falling rate; the output voltage V1 is:

[0066]

[0067] When the IGBT keeps in the turn-off state, signal S will be closed W2 signal S will be closed W1 signal S will be closed, and when the current fluctuation occurs, the positive value translation circuit will translate the voltage signal V DIDT The part close to the peak value is kept as positive value, and the rest is negative value, and the output signal V1 is used for extracting the peak value of the IGBT anti-parallel diode reverse recovery current change rate. The output voltage is formula (3).

[0068] The rectifier amplifier circuit in the peak circuit of the maximum change rate of the IGBT current filters out the negative value of the signal V1 and amplifies the positive part. The output signal V2 is calculated as:

[0069]

[0070] In the peak hold circuit, when the signal V2 is in the rising stage, the diode D3 is forward-conducted and charges C1, and the output signal V3 rises with V2. When the signal V2 is in the falling stage, the diode D3 is reverse-cut off and no longer charges C1, and the output signal V3 maintains the peak value.

[0071] In the RC discharge equivalent circuit, when the signal V3 rises above the reference voltage V REF When V PK From high level to low level, the digital control unit recognizes that the IGBT current begins to change. After a period of waiting to ensure that V3 reaches its peak, V SW3 The signal closes SW3, and the moment is t1. C1 discharges, and V3 drops until it is lower than the reference voltage V REF When V PK The time when the voltage changes from low level to high level is t2, and the time period △t from t1 to t2 can be equivalent to the peak value.

[0072]

[0073] Combining equations (1) to (5), the digital control unit can calculate the peak value of the collector current change rate dI according to Δt CMAX / dt is:

[0074]

[0075] The present invention also provides an IGBT current rate peak extraction method, the method comprising:

[0076] The maximum change rate peak value of the IGBT current is extracted by the above-mentioned TGBT current rate peak extraction circuit;

[0077] Adjust the turn-on and turn-off rates of the IGBT according to the received IGBT switching signal and the peak value of the maximum change rate of the IGBT current;

[0078] The IGBT maximum change rate peak circuit is controlled to operate according to the received IGBT switching signal.

[0079] It should be noted that the IGBT current rate peak extraction method provided in the above embodiment and the IGBT current rate peak extraction system embodiment belong to the same concept. The implementation process thereof is detailed in an IGBT half-bridge module overvoltage peak extraction system embodiment, which will not be repeated here.

[0080] In the description provided herein, numerous specific details are set forth. However, it is understood that embodiments of the application can be practiced without these specific details. In some instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description.

[0081] In addition, those skilled in the art will appreciate that the features described herein with respect to some embodiments can be combined in different embodiments, while still falling within the scope of the present application and forming different embodiments. For example, in the above embodiments, those skilled in the art can use the features in a combined manner according to the known technical solutions and the technical problems to be solved by the present application.

[0082] The above description is only the preferred embodiment of the present application, and is not intended to limit the present application in any form. Although the present application has been disclosed as above with the preferred embodiment, it is not intended to limit the present application, and any person skilled in the art can make some changes or modifications to the above-mentioned technical content with the prompt, as equivalent embodiments of equivalent changes, but as long as it does not deviate from the technical solution of the present application, any simple modification, equivalent change and modification of the above-mentioned embodiments according to the technical essence of the present application still belongs to the scope of the present application.

Claims

1. An IGBT current rate peak extraction circuit, characterized in that: The circuit comprises: A positive shift circuit is used to shift downward the detection waveform of the rate of change of the transient current of the power device switch when it decreases; A negative shift flip circuit is used to flip the detection waveform of the rate of change of the transient current of the power device switch when it rises, and shift it downward; A rectifier amplifier circuit is used to extract and amplify the voltage waveform of the portion greater than zero after being processed by the positive shift circuit or the negative shift flip circuit; Peak hold circuit, used to extract the peak value of the voltage waveform and maintain the maximum value; The RC discharge equivalent circuit is used to convert the extracted peak value into the equivalent value of the capacitor and resistor discharge time.

2. The IGBT current rate peak extraction circuit according to claim 1, characterized in that: The positive shift circuit includes a resistor R1, a resistor R2, an operational amplifier OP1, an analog switch S W1 One end of the resistor R1 is connected to the resistor R2 and the negative input terminal of the op amp OP1; the positive input terminal of the op amp OP1 is connected to the reference voltage V r1 The output end of the operational amplifier OP1 is connected to the other end of the resistor R2, and the analog switch S W1 One end is connected.

3. The IGBT current rate peak extraction circuit according to claim 1, characterized in that: The negative shift flip circuit includes a resistor R3, a resistor R4, a resistor R5, a resistor R6, an operational amplifier OP2, an analog switch S W2 One end of the resistor R3 and the other end of the resistor R1, the current change rate is extracted voltage V DIDT The other end of the resistor R3 is connected to one end of the resistor R4 and the positive input terminal of the operational amplifier OP2; the other end of the resistor R4 is grounded; one end of the resistor R5 is connected to the reference voltage V r2 The other end of the resistor R5 is connected to the negative input terminal of the op amp OP2 and one end of the resistor R6; the other end of the resistor R6 is connected to the output terminal of the op amp OP2, the analog switch S W2 One end of the analog switch S W2 The other end of the analog switch S W1 The other end of the MOSFET is connected to the output node voltage V1.

4. The IGBT current rate peak extraction circuit according to claim 1, characterized in that: The rectifier amplifier circuit includes: a diode D1, a diode D2, a resistor R7, a resistor R8 and an operational amplifier OP3; the anode of the diode D1 receives the node voltage V1; the cathode of the diode D1 is connected to the cathode of the diode D2 and the positive input terminal of the operational amplifier OP3; the anode of the diode D2 is grounded, one end of the resistor R7 is connected to one end of the resistor R8 and the negative input terminal of the operational amplifier OP3; the other end of the resistor R7 is grounded; the output end of the operational amplifier OP3 is connected to the other end of the resistor R8 and outputs the node voltage V2.

5. The IGBT current rate peak extraction circuit according to claim 1, characterized in that: The peak hold circuit includes: a transconductance amplifier OT1, a diode D3, and a capacitor C1. The positive input terminal of the transconductance amplifier OT1 receives a node voltage V2; the output terminal of the transconductance amplifier OT1 is connected to the anode of the diode D3; the negative input terminal of the transconductance amplifier OT1 is connected to the cathode of the diode D3 and one end of the capacitor C1, and outputs the node voltage V3; the other end of the capacitor C1 is grounded.

6. The IGBT current rate peak extraction circuit according to claim 1, characterized in that: The RC discharge equivalent circuit includes: a resistor R9, an analog switch S W3 , comparator CP1; one end of the resistor R9 is connected to the negative input terminal of the comparator CP1 and receives the node voltage V3; the other end of the resistor R9 is connected to the analog switch S W3 One end of the analog switch S W3 The other end of the comparator CP1 is connected to the reference voltage V REF ; Comparator CP1 output signal V PK .

7. An IGBT current rate peak extraction system, characterized in that: The system comprises: The IGBT current rate peak extraction circuit according to any one of claims 1 to 6, used to extract the maximum change rate peak of the IGBT current; The digital control unit is used to control the operation of the maximum change rate peak circuit of the IGBT current according to the received IGBT switching signal, and to generate a regulating signal for controlling the on and off of the IGBT according to the received IGBT switching signal and the maximum change rate peak of the IGBT; The adjustable gate amplifier is used to adjust the turn-on and turn-off rates of the IGBT according to the adjustment signal output by the digital control unit.

8. The IGBT current rate peak extraction system according to claim 7, characterized in that: The IGBT current rate peaks include the IGBT turn-on transient current rise rate peak, the IGBT turn-off transient current drop rate peak, and the IGBT anti-parallel diode reverse recovery current change rate peak.

9. The IGBT current rate peak extraction system according to claim 8, characterized in that: The circuit for controlling the maximum rate of change of the IGBT current according to the received IGBT switching signal specifically includes: When the digital control unit receives the PWM pulse of the turn-on signal, the adjustable gate amplifier turns on the IGBT, V SW1 The signal will S W1 Closed, V SW2 The signal will S W2 Disconnect, the negative shift flip circuit will turn the voltage signal V DIDT The part close to the peak value is converted to a positive value, and the rest is negative. The output signal V1 is used to extract the peak value of the transient current rise rate when the IGBT is turned on; When the digital control unit receives the PWM pulse of the shutdown signal, the adjustable gate amplifier turns off the IGBT, V SW2 The signal will S W2 Closed, V SW1 The signal will S W1 Disconnected, the positive shift circuit will shift the voltage signal V DIDT The part close to the peak value is kept as positive value, and the rest is negative value. The output signal V1 is used to extract the peak value of the transient current drop rate when the IGBT is turned off; When the IGBT remains in the off state, S W2 Keep it closed, S W1 Keep it in the disconnected state. When the current fluctuates, the positive shift circuit will shift the voltage signal V DIDT The part close to the peak value remains positive, and the rest is negative. The output signal V1 is used to extract the peak value of the reverse recovery current change rate of the IGBT anti-parallel diode.

10. A method for extracting the peak current rate of an IGBT, characterized in that: The method includes: Extracting the maximum change rate peak value of the IGBT current by using the IGBT current rate peak extraction circuit according to any one of claims 1 to 6; Adjust the turn-on and turn-off rates of the IGBT according to the received IGBT switching signal and the peak value of the maximum change rate of the IGBT current; The IGBT maximum change rate peak circuit is controlled to operate according to the received IGBT switching signal.

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