IGBT (Insulated Gate Bipolar Translator) driving circuit

Abstract

The utility model discloses an IGBT (Insulated Gate Bipolar Translator) driving circuit, which relates to the technical field of IGBT driving and comprises a main control unit, an upper bridge driving unit and a lower bridge driving unit, the upper bridge driving unit comprises a first driving chip and a first push-pull output unit, and the lower bridge driving unit comprises a second driving chip and a second push-pull output unit; the main control unit is connected with the first driving chip, the first driving chip is connected with the first push-pull output unit, and the first push-pull output unit is connected with a control end of an upper bridge of the IGBT module; the main control unit is connected with the second driving chip, the second driving chip is connected with the second push-pull output unit, and the second push-pull output unit is connected with the control end of the lower bridge of the IGBT module. A driving signal of an upper bridge of the IGBT module can be amplified through the first driving chip and the first push-pull output unit, and a driving signal of a lower bridge of the IGBT module can be amplified through the second driving chip and the second push-pull output unit, so that the driving capability can be improved, and driving of a high-power IGBT is realized.

Description

Technical Field

[0001] The utility model relates to the technical field of IGBT driving, in particular to an IGBT driving circuit. Background Art

[0002] The design of the insulated gate bipolar transistor (IGBT) drive circuit is the key to ensure the safe and reliable operation of the system. At present, major companies at home and abroad have a large number of related research and designs on IGBT and its drive circuit. In order to achieve the correct on and off of IGBT and the safe and stable operation of the power circuit, the correct and reasonable design of the drive circuit is essential.

[0003] At present, the driving of IGBT mainly relies on the driver chip. However, the driving capability of the driver chip is limited and it is difficult to meet the driving requirements of high-power IGBT. Utility Model Content

[0004] The technical problem to be solved by the embodiment of the utility model is

[0005] In order to solve the above problems, an embodiment of the utility model proposes an IGBT drive circuit for driving an IGBT module, wherein the IGBT drive circuit includes a main control unit, an upper bridge drive unit and a lower bridge drive unit, wherein the upper bridge drive unit includes a first drive chip and a first push-pull output unit, and the lower bridge drive unit includes a second drive chip and a second push-pull output unit; the main control unit is connected to the first drive chip, which is connected to the first push-pull output unit, which is connected to the control end of the upper bridge of the IGBT module; the main control unit is connected to the second drive chip, which is connected to the second push-pull output unit, which is connected to the control end of the lower bridge of the IGBT module.

[0006] A further technical solution is that the first push-pull output unit includes a first switch tube, a second switch tube, a first resistor, a second resistor and a first capacitor;

[0007] The control end of the first switch tube is connected to the first driving chip, the input end of the first switch tube is connected to the output end of the first positive driving power supply, and the output end of the first switch tube is connected to the control end of the upper bridge of the IGBT module through the first resistor;

[0008] The control end of the second switch tube is connected to the first driving chip, and the input end of the second switch tube is connected to the control end of the upper bridge of the IGBT module through the second resistor; the output end of the second switch tube is connected to the output end of the first negative driving power supply;

[0009] Two ends of the first capacitor are respectively connected to the control end and the output end of the upper bridge of the IGBT module.

[0010] A further technical solution is that the second push-pull output unit includes a third switch tube, a fourth switch tube, a third resistor, a fourth resistor and a second capacitor;

[0011] The control end of the third switch tube is connected to the second driving chip, the input end of the third switch tube is connected to the output end of the second positive driving power supply, and the output end of the third switch tube is connected to the control end of the lower bridge of the IGBT module through the third resistor;

[0012] The control end of the fourth switch tube is connected to the second driving chip, and the input end of the fourth switch tube is connected to the control end of the lower bridge of the IGBT module through the fourth resistor; the output end of the fourth switch tube is connected to the output end of the second negative driving power supply;

[0013] Two ends of the second capacitor are respectively connected to the control end and the output end of the lower bridge of the IGBT module.

[0014] A further technical solution is that the first push-pull output unit also includes a fifth resistor and a first bidirectional TVS tube, the fifth resistor is connected in parallel with the first capacitor, and the first bidirectional TVS tube is connected in parallel with the first capacitor.

[0015] A further technical solution is that the second push-pull output unit also includes a sixth resistor and a second bidirectional TVS tube, the sixth resistor is connected in parallel with the second capacitor, and the second bidirectional TVS tube is connected in parallel with the second capacitor.

[0016] A further technical solution is that the IGBT driving circuit further includes a first fault detection unit and a second fault detection unit;

[0017] The first fault detection unit is connected to the first driver chip and the input end of the upper bridge of the IGBT module respectively;

[0018] The second fault detection unit is connected to the second driving chip and the input end of the lower bridge of the IGBT module respectively.

[0019] Its further technical solution is that the first fault detection unit includes a third capacitor, a first diode, a seventh resistor and a ninth resistor, the first driving chip is connected to the positive electrode of the first diode, the negative electrode of the first diode is connected to the input end of the upper bridge of the IGBT module through the seventh resistor; the positive electrode of the first diode is grounded through the third capacitor; the positive electrode of the first diode is connected to the output end of the first positive driving power supply through the ninth resistor;

[0020] The second fault detection unit includes a fourth capacitor, a second diode, an eighth resistor and a tenth resistor, the second driving chip is connected to the anode of the second diode, the cathode of the second diode is connected to the input end of the lower bridge of the IGBT module through the eighth resistor; the anode of the second diode is grounded through the fourth capacitor; the anode of the second diode is connected to the output end of the second positive driving power supply through the tenth resistor;

[0021] A further technical solution is that the first fault detection unit further includes a first voltage regulator tube and a third diode, the cathode of the first voltage regulator tube is connected to the anode of the first diode, and the anode of the first voltage regulator tube is grounded; the cathode of the third diode is connected to the anode of the first diode, and the anode of the third diode is grounded;

[0022] The second fault detection unit also includes a second voltage regulator and a fourth diode, wherein the cathode of the second voltage regulator is connected to the anode of the second diode, and the anode of the second voltage regulator is grounded; the cathode of the fourth diode is connected to the anode of the second diode, and the anode of the fourth diode is grounded.

[0023] A further technical solution is that the IGBT drive circuit also includes an isolated drive power supply, the isolated drive power supply includes a transformer, the transformer includes a primary side, a first secondary side and a second secondary side, the first secondary side includes the first positive drive power supply output terminal and the first negative drive power supply output terminal; the second secondary side includes the second positive drive power supply output terminal and the second negative drive power supply output terminal.

[0024] A further technical solution is that the IGBT driving circuit further includes a buffer, and the main control unit is connected to the first driving chip and the second driving chip via the buffer.

[0025] Compared with the prior art, the technical effects achieved by the embodiments of the present invention include:

[0026] In the embodiment of the utility model, the driving signal of the upper bridge of the IGBT module can be amplified by the first driving chip and the first push-pull output unit, and the driving signal of the lower bridge of the IGBT module can be amplified by the second driving chip and the second push-pull output unit, thereby greatly improving the driving capability and realizing reliable driving of high-power IGBTs. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings herein are incorporated in and constitute a part of the specification, illustrate embodiments consistent with the present utility model, and together with the description, are used to explain the principles of the present utility model.

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the utility model or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0029] One or more embodiments are exemplarily described by pictures in the corresponding drawings, and these exemplified descriptions do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings represent similar elements, and unless otherwise stated, the figures in the drawings do not constitute proportional limitations.

[0030] Figure 1 A principle block diagram of an IGBT driving circuit provided by an embodiment of the present invention;

[0031] Figure 2 A circuit diagram of an IGBT driving circuit provided by an embodiment of the present invention;

[0032] Figure 3 Another principle block diagram of an IGBT driving circuit provided by an embodiment of the present invention;

[0033] Figure 4 A circuit diagram of an isolated driving power supply for an IGBT driving circuit provided by an embodiment of the present invention.

[0034] Reference numerals

[0035] The main control unit 100, the upper bridge driving unit 200, the lower bridge driving unit 300, the first driving chip U2, the first push-pull output unit 210, the second driving chip U3, the second push-pull output unit 310, the upper bridge 400, the lower bridge 500, the isolation driving power supply 600, the first switch tube Q1, the second switch tube Q2, the first resistor Ron_T, the second resistor Roff_T, the first capacitor C7, the fifth resistor R5, the first bidirectional TVS tube D7, the third switch tube Q3, the fourth switch tube Q4, the third resistor Ron_B, the fourth resistor Roff_B, the second capacitor C8, the sixth resistor R6, the second bidirectional TVS tube D8, The third capacitor C2, the first diode D4, the seventh resistor R8, the first voltage regulator D2, the third diode D3, the fourth capacitor C3, the second diode D9, the eighth resistor R9, the second voltage regulator D5, the fourth diode D6, the transformer T1, the primary side T11, the first secondary side T12, the second secondary side T13, the third secondary side T14, the first positive driving power output terminal VCC_T, the first negative driving power output terminal VEE_T, the second positive driving power output terminal VCC_B, the second negative driving power output terminal VEE_B, the power supply output terminal VCCO, the MOS tube Q5, the buffer U1, the ninth resistor R10, and the tenth resistor R11. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments. Similar component numbers in the drawings represent similar components. Obviously, the embodiments to be described below are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the utility model.

[0037] It should be understood that when used in this specification and the appended claims, the terms "include" and "comprises" indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0038] It should also be understood that the terms used in this utility model embodiment specification are only for the purpose of describing specific embodiments and are not intended to limit the utility model embodiments. As used in the utility model embodiment specification and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0039] See also Figure 1-4 The embodiment of the utility model provides an IGBT driving circuit, which is used to drive an IGBT module, and the IGBT module includes an upper bridge 400 and a lower bridge 500. The IGBT driving circuit includes a main control unit 100, an upper bridge driving unit 200 and a lower bridge driving unit 300, the upper bridge driving unit 200 includes a first driving chip U2 and a first push-pull output unit 210, and the lower bridge driving unit 300 includes a second driving chip U3 and a second push-pull output unit 310.

[0040] The main control unit 100 can be specifically an FPGA (Field Programmable Gate Array) chip. The first driver chip U2 and the second driver chip U3 can be specifically an optocoupler driver chip, and its model can be ACPL-352J. The optocoupler driver chip can be used to drive a high-power IGBT module, and has functions such as desaturation detection, undervoltage blocking, and drive signal fault detection. When the IGBT module is detected to be desaturated, the driver chip blocks the wave for protection and outputs a fault signal to the main control chip to achieve reliable shutdown of the IGBT module. The use of optocoupler driver chips has reliable performance, high stability, low switching loss, and more reasonable design, and is particularly suitable for the field of high-power IGBT driving.

[0041] The main control unit 100 is connected to the first driver chip U2, the first driver chip U2 is connected to the first push-pull output unit 210, the first push-pull output unit 210 is connected to the control end of the upper bridge 400 of the IGBT module; the main control unit 100 is connected to the second driver chip U3, the second driver chip U3 is connected to the second push-pull output unit 310, the second push-pull output unit 310 is connected to the control end of the lower bridge 500 of the IGBT module.

[0042] In the embodiment of the utility model, the driving signal of the upper bridge 400 of the IGBT module can be amplified by the first driving chip U2 and the first push-pull output unit 210, and the driving signal of the lower bridge 500 of the IGBT module can be amplified by the second driving chip U3 and the second push-pull output unit 310, thereby greatly improving the driving capability and realizing reliable driving of high-power IGBTs.

[0043] Furthermore, in one embodiment, the first push-pull output unit 210 includes a first switch tube Q1, a second switch tube Q2, a first resistor Ron_T, a second resistor Roff_T, a first capacitor C7, a fifth resistor R5 and a first bidirectional TVS tube D7.

[0044] The control end of the first switch tube Q1 is connected to the first driving chip U2, the input end of the first switch tube Q1 is connected to the first positive driving power output end VCC_T, and the output end of the first switch tube Q1 is connected to the control end of the upper bridge 400 of the IGBT module through the first resistor Ron_T.

[0045] The control end of the second switch tube Q2 is connected to the first driving chip U2, and the input end of the second switch tube Q2 is connected to the control end of the upper bridge 400 of the IGBT module through the second resistor Roff_T; the output end of the second switch tube Q2 is connected to the first negative driving power supply output end VEE_T.

[0046] The two ends of the first capacitor C7 are respectively connected to the control end and the output end IGBT_T of the upper bridge 400 of the IGBT module. The fifth resistor R5 is connected in parallel with the first capacitor C7, and the first bidirectional TVS tube D7 is connected in parallel with the first capacitor C7.

[0047] It should be noted that the first switch tube Q1 and the second switch tube Q2 have one end where current flows in as their input end and one end where current flows out as their output end. The first switch tube Q1 may be an NPN transistor, and the second switch tube Q2 may be a PNP transistor.

[0048] Furthermore, the second push-pull output unit 310 includes a third switch tube Q3, a fourth switch tube Q4, a third resistor Ron_B, a fourth resistor Roff_B, a second capacitor C8, a sixth resistor R6 and a second bidirectional TVS tube D8.

[0049] The control end of the third switch tube Q3 is connected to the second driving chip U3, the input end of the third switch tube Q3 is connected to the second positive driving power output end VCC_B, and the output end of the third switch tube Q3 is connected to the control end of the lower bridge 500 of the IGBT module through the third resistor Ron_B.

[0050] The control end of the fourth switch tube Q4 is connected to the second driving chip U3, and the input end of the fourth switch tube Q4 is connected to the control end of the lower bridge 500 of the IGBT module through the fourth resistor Roff_B; the output end of the fourth switch tube Q4 is connected to the second negative driving power output end VEE_B.

[0051] The two ends of the second capacitor C8 are respectively connected to the control end and the output end IGBT_B of the lower bridge 500 of the IGBT module. The sixth resistor R6 is connected in parallel with the second capacitor C8, and the second bidirectional TVS tube D8 is connected in parallel with the second capacitor C8.

[0052] It should be noted that the third switch tube Q3 and the fourth switch tube Q4 have one end where current flows in as their input end and one end where current flows out as their output end. The third switch tube Q3 may be an NPN transistor, and the fourth switch tube Q4 may be a PNP transistor.

[0053] Furthermore, the IGBT driving circuit also includes a first fault detection unit and a second fault detection unit.

[0054] The first fault detection unit is connected to the first driver chip U2 and the input end of the upper bridge 400 of the IGBT module respectively. The second fault detection unit is connected to the second driver chip U3 and the input end of the lower bridge 500 of the IGBT module respectively.

[0055] Further, the first fault detection unit includes a third capacitor C2, a first diode D4, a seventh resistor R8, a first voltage regulator D2, a ninth resistor R10, and a third diode D3; the first driver chip U2 is connected to the positive electrode of the first diode D4, and the negative electrode of the first diode D4 is connected to the input end of the upper bridge 400 of the IGBT module through the seventh resistor R8; the positive electrode of the first diode D4 is grounded through the third capacitor C2; the positive electrode of the first voltage regulator D2 is connected to the negative electrode of the first diode D4, and the positive electrode of the first voltage regulator D2 is grounded; the negative electrode of the third diode D3 is connected to the positive electrode of the first diode D4, and the positive electrode of the third diode D3 is grounded; the positive electrode of the first diode D4 is connected to the positive electrode of the first diode D4, and the positive electrode of the third diode D3 is grounded; the positive electrode of the first diode D4 is connected to the first positive drive power output terminal VCC_T through the ninth resistor R10.

[0056] The second fault detection unit includes a fourth capacitor C3, a second diode D9, an eighth resistor R9, a second voltage regulator D5, a tenth resistor R11, and a fourth diode D6. The second driving chip U3 is connected to the anode of the second diode D9, and the cathode of the second diode D9 is connected to the input end of the lower bridge 500 of the IGBT module through the eighth resistor R9; the anode of the second diode D9 is grounded through the fourth capacitor C3; the cathode of the second voltage regulator D5 is connected to the anode of the second diode D9, and the anode of the second voltage regulator D5 is grounded; the cathode of the fourth diode D6 is connected to the anode of the second diode D9, and the anode of the fourth diode D6 is grounded; the anode of the second diode D9 is connected to the second positive driving power supply output terminal VCC_B through the tenth resistor R11.

[0057] Furthermore, the IGBT driving circuit also includes an isolated driving power supply 600, the isolated driving power supply 600 includes a transformer T1, the transformer T1 includes a primary side T11, a first secondary side T12 and a second secondary side T13, the first secondary side T12 includes the first positive driving power supply output terminal VCC_T and the first negative driving power supply output terminal VEE_T; the second secondary side T13 includes the second positive driving power supply output terminal VCC_B and the second negative driving power supply output terminal VEE_B.

[0058] The first positive driving power output terminal VCC_T and the second positive driving power output terminal VCC_B are used to output a positive voltage. The first negative driving power output terminal VEE_T and the second negative driving power output terminal VEE_B are used to output a negative voltage.

[0059] See also Figure 4, the isolated driving power supply 600 can adopt a flyback switching power supply topology. The transformer T1 also includes a third secondary side T14, and the third secondary side T14 includes a power supply output terminal VCCO, and the power supply output terminal VCCO is used to connect to a switching power supply management chip to supply power to the switching power supply management chip. The switching power supply management chip is connected to the MOS tube Q5 of the primary side T11 of the transformer T1 to drive the MOS tube Q5.

[0060] Furthermore, the IGBT driving circuit further includes a buffer U1, and the main control unit 100 is connected to the first driving chip U2 and the second driving chip U3 via the buffer U1. The buffer U1 may be specifically a linear buffer.

[0061] Working principle: The signals PWM_H and PWM_L output by the main control unit are output as the upper bridge drive signal PWM_H1 and the lower bridge drive signal PWM_L1 after passing through the buffer. Taking the upper bridge drive as an example, PWM_H1 and PWM_L1 are respectively input to PIN_6 and PIN_7 of the first driver chip U2. When PWM_H1 is low and PWM_L1 is high, the primary diode of the first driver chip U2 is turned on, and the outputs of PIN_10 and PIN_11 of the first driver chip U2 are high level. The first switch tube Q1 is turned on, and the second switch tube Q2 is turned off. The first positive drive power supply output terminal VCC_T charges the first capacitor C7 through the first resistor Ron_T. When the voltage across the first capacitor C7 reaches the turn-on threshold voltage, the output terminal IGBT_T of the upper bridge 400 of the IGBT is turned on; when PWM_H1 is high and PWM_L1 is When the voltage is low, the primary diode of the first driver chip U2 is cut off, the PIN_10 and PIN_11 outputs of the first driver chip U2 are low level, the first switch tube Q1 is cut off, the second switch tube Q2 is turned on, and the first negative drive power supply output terminal VEE_T discharges the first capacitor C7 through the second resistor Roff_T. When the voltage across the first capacitor C7 is lower than the threshold voltage, the output terminal IGBT_T of the IGBT upper bridge 400 is turned off, and the low level of the drive signal is valid; wherein, the first bidirectional TVS tube D7 is used to clamp the gate-level drive voltage to prevent the IGBT module from being damaged due to excessive short-circuit current; the fifth resistor R5 can accelerate the shutdown of the IGBT module to further ensure fast shutdown. PIN_14 of the first driver chip U2 can realize module desaturation detection. When the IGBT module operates normally, the Vce saturation voltage drop is about 2V, and the first diode D4 is turned on. At this time, the first positive drive power output terminal VCC_T charges the collector of the IGBT module through the ninth resistor R10, and the voltage across the third capacitor C2 is clamped and lower than the desaturation action threshold voltage; when the upper and lower bridges of the IGBT module are directly connected and the bridge arm is short-circuited, Vce exits the saturation area and quickly rises to the bus voltage, the first diode D4 is reversely cut off, and the first positive drive power output terminal VCC_T charges the third capacitor C2 through the ninth resistor R10. The voltage across the third capacitor C2 rises to the threshold voltage. When the PIN_14 of the first driver chip U2 detects the voltage, the driver chip performs hardware sealing and outputs a fault detection signal to the host computer. The driving and protection logic of the lower bridge drive signal is consistent with the upper bridge drive principle, and will not be repeated.

[0062] The electrical characteristics, conduction principles, signal lines and principles of triodes, MOS tubes and IGBT modules are the basic knowledge of power electronics. Those skilled in the art can understand their meanings and will not be explained in detail here.

[0063] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0064] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0065] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present utility model, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0066] In the present invention, unless otherwise clearly specified and limited, the terms "install", "connect", "connect", "fix" and the like should be understood in a broad sense, for example, it can be connected, detachably connected, or integrated; it can be mechanically connected or electrically connected; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0067] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0068] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representation of the above terms should not be understood as necessarily being directed to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification.

[0069] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is intended to include these modifications and variations.

[0070] The above is a specific implementation of the utility model, but the protection scope of the utility model is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the utility model, and these modifications or replacements should be included in the protection scope of the utility model. Therefore, the protection scope of the utility model should be based on the protection scope of the claims.

Claims

1. An IGBT driving circuit, characterized in that: Used to drive an IGBT module, the IGBT driving circuit includes a main control unit, an upper bridge driving unit and a lower bridge driving unit, the upper bridge driving unit includes a first driving chip and a first push-pull output unit, and the lower bridge driving unit includes a second driving chip and a second push-pull output unit; the main control unit is connected to the first driving chip, the first driving chip is connected to the first push-pull output unit, and the first push-pull output unit is connected to the control end of the upper bridge of the IGBT module; the main control unit is connected to the second driving chip, the second driving chip is connected to the second push-pull output unit, and the second push-pull output unit is connected to the control end of the lower bridge of the IGBT module.

2. The IGBT driving circuit according to claim 1, characterized in that: The first push-pull output unit includes a first switch tube, a second switch tube, a first resistor, a second resistor and a first capacitor; The control end of the first switch tube is connected to the first driving chip, the input end of the first switch tube is connected to the output end of the first positive driving power supply, and the output end of the first switch tube is connected to the control end of the upper bridge of the IGBT module through the first resistor; The control end of the second switch tube is connected to the first driving chip, and the input end of the second switch tube is connected to the control end of the upper bridge of the IGBT module through the second resistor; the output end of the second switch tube is connected to the output end of the first negative driving power supply; Two ends of the first capacitor are respectively connected to the control end and the output end of the upper bridge of the IGBT module.

3. The IGBT driving circuit according to claim 2, characterized in that: The second push-pull output unit includes a third switch tube, a fourth switch tube, a third resistor, a fourth resistor and a second capacitor; The control end of the third switch tube is connected to the second driving chip, the input end of the third switch tube is connected to the output end of the second positive driving power supply, and the output end of the third switch tube is connected to the control end of the lower bridge of the IGBT module through the third resistor; The control end of the fourth switch tube is connected to the second driving chip, and the input end of the fourth switch tube is connected to the control end of the lower bridge of the IGBT module through the fourth resistor; the output end of the fourth switch tube is connected to the output end of the second negative driving power supply; Two ends of the second capacitor are respectively connected to the control end and the output end of the lower bridge of the IGBT module.

4. The IGBT driving circuit according to claim 2, characterized in that: The first push-pull output unit further includes a fifth resistor and a first bidirectional TVS tube. The fifth resistor is connected in parallel with the first capacitor, and the first bidirectional TVS tube is connected in parallel with the first capacitor.

5. The IGBT driving circuit according to claim 3, characterized in that: The second push-pull output unit further includes a sixth resistor and a second bidirectional TVS tube. The sixth resistor is connected in parallel with the second capacitor, and the second bidirectional TVS tube is connected in parallel with the second capacitor.

6. The IGBT driving circuit according to claim 3, characterized in that: The IGBT driving circuit further includes a first fault detection unit and a second fault detection unit; The first fault detection unit is connected to the first driver chip and the input end of the upper bridge of the IGBT module respectively; The second fault detection unit is connected to the second driving chip and the input end of the lower bridge of the IGBT module respectively.

7. The IGBT driving circuit according to claim 6, characterized in that: The first fault detection unit includes a third capacitor, a first diode, a seventh resistor and a ninth resistor, the first driving chip is connected to the anode of the first diode, the cathode of the first diode is connected to the input end of the upper bridge of the IGBT module through the seventh resistor; the anode of the first diode is grounded through the third capacitor; the anode of the first diode is connected to the output end of the first positive driving power supply through the ninth resistor; The second fault detection unit includes a fourth capacitor, a second diode, an eighth resistor and a tenth resistor. The second driving chip is connected to the anode of the second diode, and the cathode of the second diode is connected to the input end of the lower bridge of the IGBT module through the eighth resistor; the anode of the second diode is grounded through the fourth capacitor; and the anode of the second diode is connected to the output end of the second positive driving power supply through the tenth resistor.

8. The IGBT driving circuit according to claim 7, characterized in that: The first fault detection unit further includes a first voltage regulator tube and a third diode, wherein the cathode of the first voltage regulator tube is connected to the anode of the first diode, and the anode of the first voltage regulator tube is grounded; the cathode of the third diode is connected to the anode of the first diode, and the anode of the third diode is grounded; The second fault detection unit also includes a second voltage regulator and a fourth diode, wherein the cathode of the second voltage regulator is connected to the anode of the second diode, and the anode of the second voltage regulator is grounded; the cathode of the fourth diode is connected to the anode of the second diode, and the anode of the fourth diode is grounded.

9. The IGBT driving circuit according to claim 3, characterized in that: The IGBT drive circuit also includes an isolated drive power supply, the isolated drive power supply includes a transformer, the transformer includes a primary side, a first secondary side and a second secondary side, the first secondary side includes the first positive drive power output terminal and the first negative drive power output terminal; the second secondary side includes the second positive drive power output terminal and the second negative drive power output terminal.

10. The IGBT driving circuit according to claim 1, characterized in that: The IGBT driving circuit further includes a buffer, and the main control unit is connected to the first driving chip and the second driving chip via the buffer.

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