Driving circuit and inverter welding machine

Abstract

The utility model relates to a driving circuit and an inverter welding machine. The drive circuit comprises a drive chip and a voltage-stabilized source, the input signal end of the drive chip inputs drive signals, the output signal end of the drive chip is connected with the gate pole of one silicon carbide power device of the inverter welding machine, and the clamping signal output end of the drive chip is connected with the gate pole of one silicon carbide power device of the inverter welding machine. The input end of the voltage-stabilized source inputs a first power signal, and the output end of the voltage-stabilized source is connected with a source electrode of one silicon carbide power device of the inverter welding machine. The drive circuit can conveniently drive the silicon carbide field effect transistor in the inverter welding machine.

Description

TECHNICAL FIELD

[0001] The utility model relates to welding machine technical field especially drive circuit and inverter welding machine of a kind of. BACKGROUND

[0002] As the third generation power semiconductor device, silicon carbide field effect transistor has the following advantages: first, high voltage withstand characteristic, the current production can reach 3300V or more;Second, low on-resistance, in the same rated voltage, the on-resistance of silicon carbide field effect transistor is significantly lower than silicon-based device.Third, high-frequency characteristic is excellent, switching loss is low, more suitable for high-frequency inverter circuit, the switching loss of silicon carbide MOS tube can be reduced by more than 60% compared with IGBT, therefore, in inverter welding machine using silicon carbide device, the inverter frequency of inverter welding machine can be greatly improved, while reducing the volume of magnetic element, the dynamic response speed of welding machine is significantly improved, so that the welding performance of welding machine is significantly improved.

[0003] The mainstream inverter welding machine adopts bridge inverter topology, such as half-bridge inverter topology and full-bridge inverter topology, and the full-bridge inverter topology can be regarded as the combination of two half-bridge topologies.The driving technology of silicon carbide is the key technology for the successful application of silicon carbide power device, and therefore, a driving circuit for half-bridge inverter topology is urgently needed, which can conveniently drive the silicon carbide field effect transistor in the inverter welding machine. SUMMARY

[0004] Therefore, it is necessary to provide a driving circuit and inverter welding machine for conveniently driving the silicon carbide field effect transistor in the inverter welding machine.

[0005] In a first aspect, the application provides a driving circuit, comprising:

[0006] The driving chip inputs a driving signal at the input signal end, and the output signal end is connected to the gate of a silicon carbide power device of the inverter welding machine, and the clamping signal output end is connected to the gate of a silicon carbide power device of the inverter welding machine.

[0007] The voltage stabilizing power supply inputs a first power signal at the input end, and the output end is connected to the source of a silicon carbide power device of the inverter welding machine.

[0008] In one embodiment, the voltage stabilizing power supply comprises:

[0009] The first resistor has one end connected to the first power signal and the first end of the first capacitor, and the other end connected to the first end of the voltage stabilizing tube, the second end of the first resistor, the first end of the second capacitor, and the output end of the voltage stabilizing power supply.

[0010] The second end of the voltage stabilizing tube and the second end of the second capacitor are connected to the ground of a silicon carbide power device of the inverter welding machine.

[0011] In one of the embodiments, further comprising:

[0012] a first decoupling capacitor, one end of which is connected to the first pin of the driving chip and the input DC power, and the other end of which is grounded;

[0013] a second decoupling capacitor, one end of which is connected to the second pin of the driving chip and the first power signal, and the other end of which is connected to the ground of a silicon carbide power device of the inverter welder.

[0014] In one of the embodiments, further comprising:

[0015] a second resistor, one end of which is connected to the driving signal, and the other end of which is connected to the input signal end of the driving chip;

[0016] a third resistor, one end of which is connected to the other end of the second resistor, and the other end of which is grounded.

[0017] In one of the embodiments, further comprising:

[0018] a power module, an input end of which is connected to the input DC power, and an output end of which is connected to the input end of the voltage stabilizing power supply, for providing the first power signal to the voltage stabilizing power supply.

[0019] In one of the embodiments, the power module comprises:

[0020] a current conversion unit, an input end of which is connected to the input DC power, for converting the input DC power into high-frequency AC power;

[0021] a transformer unit, a primary of which is connected to the output end of the current conversion unit;

[0022] a rectifier and filter unit, an input end of which is connected to the secondary of the transformer unit, and an output end of which is connected to the input end of the voltage stabilizing power supply.

[0023] In one of the embodiments, the current conversion unit comprises:

[0024] a third capacitor and a fourth capacitor, first ends of the third capacitor and the fourth capacitor are both connected to the input DC power, and second ends of the third capacitor and the fourth capacitor are both grounded;

[0025] a current conversion chip, input pins of which are respectively connected to the input DC power and the ground, and output pins of which are respectively connected to the primary of the transformer unit.

[0026] In one of the embodiments, a turns ratio of the transformer unit is 14:21.

[0027] In a second aspect, the application further provides an inverter welder, comprising:

[0028] a first bridge arm comprising a first silicon carbide power device;

[0029] a second bridge arm comprising a second silicon carbide power device;

[0030] a first driving circuit;

[0031] a second driving circuit;

[0032] The first driving circuit and the second driving circuit are the driving circuit described in any one of the above embodiments.

[0033] In one of the embodiments, the turn-on resistance and the turn-off resistance of the first silicon carbide power device are placed close to the first silicon carbide power device, and the turn-on resistance and the turn-off resistance of the second silicon carbide power device are placed close to the second silicon carbide power device.

[0034] The driving circuit and the inverter welder comprise a driving chip and a voltage stabilizing power supply. An input signal end of the driving chip inputs a driving signal, an output signal end is connected with a gate of a silicon carbide power device of the inverter welder, and a clamping signal output end is connected with the gate of the silicon carbide power device of the inverter welder. An input end of the voltage stabilizing power supply inputs a first power signal, and an output end is connected with a source of a silicon carbide power device of the inverter welder. In this way, the silicon carbide field effect tube in the inverter welder can be conveniently driven, and when the silicon carbide field effect tube is turned off, the gate of the silicon carbide field effect tube is clamped to avoid the interference signal caused by the Miller capacitor from causing the silicon carbide field effect tube to be misdirected on. The upper and lower bridge arms of the half-bridge inverter topology cannot appear to be directly connected. Direct connection will cause a huge short-circuit current, which will directly cause the bridge arm to burn out. The Miller clamping function can well avoid the bridge arm direct connection caused by the misdirected on of the silicon carbide due to interference. This is very helpful for improving the reliability of the inverter circuit. BRIEF DESCRIPTION OF DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the related art, the drawings needed to be used in the description of the embodiments of the present application or the related art will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and those skilled in the art can obtain other related drawings without creative labor.

[0036] Figure 1 A circuit diagram of the driving circuit in one embodiment;

[0037] Figure 2 A circuit diagram of the power supply module of the driving circuit in one embodiment;

[0038] Figure 3A circuit diagram of the inverter motor in one embodiment;

[0039] Figure 4 A template diagram of the driving circuit in one embodiment.

[0040] Explanation of reference signs: 1 driving circuit substrate, 2 first transformer unit, 3 second transformer unit, 4 first power module, 5 second power module, 6 first driving chip, 7 second driving chip, 8 driving circuit input interface third row of pins, 9 first row of pins, 10 second row of pins; U1 driving chip, R3 first resistor, C7 first capacitor, C8 second capacitor, ZD1 voltage stabilizing tube, C1 first decoupling capacitor, C6 second decoupling capacitor, R2 second resistor, R1 third resistor, T1 transformer unit, C2 third capacitor, C3 fourth capacitor, U4 current conversion chip, Q1 first bridge arm, Q2 second bridge arm, D1 diode, D2 diode, D3 diode, D4 diode. DETAILED DESCRIPTION

[0041] In order to facilitate the understanding of the present application, the present application will be described more fully below with reference to the accompanying drawings. The embodiments of the present application are shown in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

[0042] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs. The terminology used in the specification of the present application is only for the purpose of describing specific embodiments and is not intended to limit the present application.

[0043] It can be understood that the terms "first", "second" and the like used in the present application can be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish the first element from another element. For example, without departing from the scope of the present application, the first resistor can be referred to as the second resistor, and similarly, the second resistor can be referred to as the first resistor. The first resistor and the second resistor are both resistors, but they are not the same resistor.

[0044] It can be understood that "connection" in the following embodiments, if the circuits, modules, units and the like connected to each other have the transmission of electrical signals or data, should be understood as "electrical connection", "communication connection" and the like.

[0045] As used herein, the singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise. It will be further understood that the terms "comprises", "comprising", "includes" and / or "including", or the like, when used in this specification, specify the presence of stated features, integers, steps, operations, elements, components, or combinations thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

[0046] In combination Figure 1 As shown, Figure 1 The circuit diagram is a driving circuit in an embodiment, and the driving circuit comprises a driving chip U1 and a voltage stabilizing power supply. The input signal end of the driving chip U1 inputs a driving signal inputa, the output signal end is connected with the gate of a silicon carbide power device of an inverter welder, and the clamping signal output end is connected with the gate of a silicon carbide power device of the inverter welder. The input end of the voltage stabilizing power supply inputs a first power signal VDD1, and the output end is connected with the source of a silicon carbide power device of the inverter welder.

[0047] In combination Figure 1 As shown, the driving chip U1 can adopt a driving chip U1PN7902M, and can also adopt other similar driving chips U1, which are not specifically limited here. The driving chip U1 provides the gate of a silicon carbide power device of the inverter welder with a driving signal inputa and a clamping signal.

[0048] The clamping signal is used to clamp the gate of the silicon carbide field effect tube during the off period of the silicon carbide field effect tube, so as to avoid the interference signal caused by the Miller capacitor from causing the mis-conduction of the silicon carbide field effect tube. The upper and lower bridge arms of the half-bridge inverter topology cannot appear through phenomenon absolutely. The through phenomenon will directly cause the bridge arm to be burned out due to the huge short-circuit current. The Miller clamping function can well avoid the bridge arm through phenomenon caused by the mis-conduction of the silicon carbide due to the interference, and is helpful to improve the reliability of the inverter circuit.

[0049] The voltage stabilizing power supply provides a silicon carbide field effect tube with a negative voltage of about 3.6V during the off period, so as to improve the reliability of the off of the silicon carbide field effect tube.

[0050] The driving circuit comprises a driving chip U1 and a voltage stabilizing power supply, the input signal end of the driving chip U1 inputs a driving signal inputa, the output signal end is connected with the gate of a silicon carbide power device of the inverter welder, and the clamping signal output end is connected with the gate of a silicon carbide power device of the inverter welder; the input end of the voltage stabilizing power supply inputs a first power signal VDD1, and the output end is connected with the source of a silicon carbide power device of the inverter welder. Thus, the silicon carbide field effect tube in the inverter welder can be conveniently driven, and when the silicon carbide field effect tube is turned off, the gate of the silicon carbide field effect tube is clamped to avoid the interference signal caused by the Miller capacitor from causing the silicon carbide field effect tube to be misdirected on. The upper and lower bridge arms of the half-bridge inverter topology cannot appear through phenomenon, and the through phenomenon will directly cause the bridge arm to be burned out due to a huge short-circuit current. The Miller clamping function can well avoid the bridge arm through phenomenon caused by the misdirected on of the silicon carbide due to interference. This is very helpful for improving the reliability of the inverter circuit.

[0051] The voltage stabilizing power supply refers to a power supply circuit that can maintain the output voltage basically unchanged when the input grid voltage fluctuates or the load changes. There are many types of voltage stabilizing circuits. According to the type of output current, they can be divided into DC voltage stabilizing circuits and AC voltage stabilizing circuits. According to the connection mode of the voltage stabilizing circuit and the load, they can be divided into series voltage stabilizing circuits and parallel voltage stabilizing circuits. According to the working state of the adjusting tube, they can be divided into linear voltage stabilizing circuits and switching voltage stabilizing circuits. According to the circuit type, they can be divided into simple voltage stabilizing circuits, feedback voltage stabilizing circuits, and voltage stabilizing circuits with amplification links.

[0052] In one of the optional embodiments, the voltage stabilizing power supply comprises a first resistor R3 and a voltage stabilizing tube ZD1. One end of the first resistor R3 is connected with the first power signal VDD1 and the first end of the first capacitor C7, and the other end is connected with the first end of the voltage stabilizing tube ZD1, the second end of the first resistor, the first end of the second capacitor C8, and the output end of the voltage stabilizing power supply; the second end of the voltage stabilizing tube ZD1 is connected with the ground VSS1 of a silicon carbide power device of the inverter welder. In other embodiments, the structure of the voltage stabilizing power supply can be other, which is not specifically limited here.

[0053] The first resistor R3 is a current limiting resistor, and the voltage stabilizing tube ZD1 is a voltage stabilizing tube ZD1 with a target voltage of 3.6V. The voltage stabilizing power supply can provide a negative voltage of about 3.6V for the silicon carbide field effect tube during the off period, thereby improving the reliability of the silicon carbide field effect tube in the off period.

[0054] In one optional embodiment, the driving circuit further includes a first decoupling capacitor C1 and a second decoupling capacitor C6. One end of the first decoupling capacitor C1 is connected to the first pin of the driving chip U1 and the input DC power (+15V in this embodiment, but other values ​​may be used in other embodiments), and the other end is grounded to GND. One end of the second decoupling capacitor C6 is connected to the second pin of the driving chip U1 and the first power signal VDD1, and the other end is connected to the ground VSS1 of a silicon carbide power device of the inverter welding machine.

[0055] The first decoupling capacitor C1 and the second decoupling capacitor C6 are decoupling capacitors for the driver chip U1 to eliminate high-frequency noise and ensure the normal operation of the components.

[0056] In one optional embodiment, the driving circuit further includes a second resistor R2 and a third resistor R1. One end of the second resistor R2 is connected to the driving signal inputa, and the other end is connected to the input signal terminal of the driving chip U1. One end of the third resistor R1 is connected to the other end of the second resistor R2, and the other end is grounded to GND.

[0057] For ease of understanding, combined with Figure 1 As shown, Figure 1 The driving section of the driving circuit includes a driving chip U1, a first capacitor C7, a second capacitor C8, a first decoupling capacitor C1, a second decoupling capacitor C6, a first resistor R3, a second resistor R2, a third resistor R1, and a Zener diode ZD1. The first decoupling capacitor C1 and the second decoupling capacitor C6 are decoupling capacitors of the driver chip U1. The drive signal inputa is input to pin 2 of the driver chip U1 through the second resistor R2. Pin 2 is the signal input terminal of the chip (i.e., the input signal terminal of the driver chip U1 mentioned above). Pin 6 is the output terminal of the isolated drive signal inputa (i.e., the drive signal inputa terminal of the driver chip U1 mentioned above). It is connected to the gate of the silicon carbide field-effect transistor (SiMAT) through the first row of pins CN1 to drive the SiMAT. Pin 7 is the Miller clamp pin, which is the clamp signal output terminal. During the turn-off period of the SiMAT, the gate of the SiMAT is clamped to avoid interference signals caused by the Miller capacitor that may cause the SiMAT to be falsely turned on. The upper and lower bridge arms of the half-bridge inverter topology must not have shoot-through. Shoo-through will cause a huge short-circuit current that will directly burn out the bridge arm. The Miller clamp function can effectively prevent the bridge arm shoot-through caused by interference leading to false turn-on of the SiMAT. It greatly helps to improve the reliability of inverter circuits.

[0058] The first resistor R3 is a current-limiting resistor. The first resistor R3 and the Zener diode ZD1 form a regulated power supply, which provides a negative voltage of about 3.6V to the silicon carbide field-effect transistor during the turn-off period, thereby improving the reliability of the turn-off of the silicon carbide field-effect transistor.

[0059] Combination Figure 1 As shown, the driving circuit also includes a first row of pins CN1, through which the driving gate signal G1, Miller clamp signal C1, silicon carbide field-effect transistor (S-EFET) source signal S1 and silicon carbide field-effect transistor (SFET) are connected. To reduce interference, the gate turn-on resistor and turn-off resistor of the silicon carbide drive are placed close to the silicon carbide field-effect transistor. Therefore, the turn-on and turn-off resistors do not appear in this driving circuit.

[0060] In one optional embodiment, the driving circuit further includes a power supply module, with its input terminal connected to an input DC power supply (+15V in this embodiment, and other values ​​in other embodiments) and its output terminal connected to the input terminal of a regulated power supply, for providing a first power signal VDD1 to the regulated power supply.

[0061] Specifically, in combination Figure 2 As shown, Figure 2 This is a circuit diagram of the power supply module of the drive circuit in one embodiment. In one optional embodiment, the power supply module includes: a current conversion unit, a transformer unit T1, and a rectifier and filter unit. The input terminal of the current conversion unit is connected to the input DC power (+15V in this embodiment, but other values ​​may be used in other embodiments) to convert the input DC power into high-frequency AC power. The primary winding of the transformer unit T1 is connected to the output terminal of the current conversion unit. The input terminal of the rectifier and filter unit is connected to the secondary winding of the transformer unit T1, and the output terminal is connected to the input terminal of the regulated power supply.

[0062] In one optional embodiment, the current conversion unit includes a third capacitor C2, a fourth capacitor C3, and a current conversion chip U4. The first terminals of the third capacitor C2 and the fourth capacitor C3 are both connected to the input DC power (+15V in this embodiment, but other values ​​in other embodiments), and the second terminals are both grounded to GND. The input pins of the current conversion chip U4 are connected to the input DC power and grounded to GND, respectively, and the output pins are connected to the primary winding of the transformer unit T1.

[0063] In one alternative embodiment, the turns ratio of transformer unit T1 is 14:21.

[0064] The power module includes a current conversion unit, a transformer unit T1 and a rectification filter unit, wherein the current conversion power supply includes a third capacitor C2, a fourth capacitor C3 and a current conversion chip U4, the third capacitor C2 and the fourth capacitor C3 are filter capacitors, the current conversion chip U4 is a special chip VPS8701 for isolated power supply, and other similar functional chips can also be used. The transformer unit T1 can be a toroidal transformer, and the rectification filter unit can include a full-bridge rectifier circuit and a fifth capacitor C4, and the fifth capacitor C4 is a filter capacitor.

[0065] The transformer unit T1 is a device for changing alternating voltage by electromagnetic induction principle, and has functions of voltage conversion, current conversion, impedance conversion, isolation, voltage stabilization (magnetic saturation transformer) and the like.

[0066] The transformer unit T1 includes a core (or magnetic core) and a coil, and the coil has two or more windings, wherein the winding connected with the alternating power supply is called a primary coil (primary side coil, original coil), and the remaining windings are called secondary coils (secondary side coil, secondary coil). The simplest core transformer is composed of a core made of soft magnetic material and a primary coil L1 and a secondary coil L2 with different number of turns wound on the core.

[0067] The full-bridge rectifier is provided with a first input pole and a second input pole for connecting the alternating input power Vin, and a first output pole and a second output pole for outputting the direct current Vout. The full-bridge rectifier is used for converting alternating current into direct current. The full-bridge rectifier includes four diodes connected in head-to-tail manner: diode D1, diode D2, diode D3 and diode D4. Among them, the anode of diode D1 is connected with the cathode of diode D4, the anode of diode D2 is connected with the cathode of diode D3, the cathode of diode D1 is connected with the cathode of diode D2, and the anode of diode D3 is connected with the anode of diode D4. The common connection point of diode D1 and diode D4 serves as the first input pole of the input power Vin, and the common connection point of diode D2 and diode D3 serves as the second input pole of the input power Vin. The common connection point of diode D1 and diode D2 serves as the first input pole of the output direct current Vout, and the common connection point of diode D3 and diode D4 serves as the second input pole of the output direct current Vout.

[0068] Among them, in combination with Figure 2As shown, the VPS 8701 converts the input DC +15V into a 250KHZ high-frequency AC square wave signal, which is input to the primary of the ring transformer. The turns ratio of the transformer unit T1 is designed to be 14:21, so the transformer unit T1 raises the input DC +15V to 22.5V. The full-bridge rectifier circuit rectifies the AC square wave voltage output by the transformer unit T1 to a DC 21.5V (minus the voltage drop of two diodes), which is used as the first power supply signal VDD1 of the driving circuit.

[0069] In one of the optional embodiments, the application also provides an inverter welding machine, which comprises Figure 3 As shown, the driving board comprises: a first bridge arm Q1, a second bridge arm Q2, a first driving circuit, and a second driving circuit. The first driving circuit and the second driving circuit are completely the same, because the driving principles of the first bridge arm Q1 and the second bridge arm Q2 are completely the same, so the driving board is composed of two completely same driving circuits. The principle of only one of the driving circuits is described above, and the other circuit is completely the same.

[0070] The inverter welding machine is a half-bridge inverter topology, which comprises two silicon carbide power devices and two bridge arm capacitors, thereby forming the first bridge arm Q1 and the second bridge arm Q2. The first bridge arm Q1 and the second bridge arm Q2 are not in common, so the two-way driving of the half-bridge driving module requires isolated power supply.

[0071] The first driving circuit and the second driving circuit are the driving circuit in any one of the above-mentioned embodiments. The first driving circuit is used to drive the first bridge arm Q1, and the second driving circuit is used to drive the second bridge arm Q2.

[0072] In addition, the input port of the inverter welding machine is a third row of pins, which comprises four input signals: input DC (in this embodiment, +15V, and in other embodiments, it can be other voltage values), ground GND, driving signal inputa of the first bridge arm Q1, and driving signal inputb of the second bridge arm Q2 (not shown in the figure).

[0073] In one of the optional embodiments, the turn-on resistor and the turn-off resistor of the first silicon carbide power device are placed close to the first silicon carbide power device, and the turn-on resistor and the turn-off resistor of the second silicon carbide power device are placed close to the second silicon carbide power device, so as to reduce interference.

[0074] For the convenience of understanding, the application will be described below in combination with Figure 4 As shown, Figure 4A module layout diagram of the driving circuit in an embodiment, in which the driving circuit comprises a driving circuit substrate 1, a first transformer unit 2, a second transformer unit 3, a first power supply module 4, a second power supply module 5, a first driving chip 6, a second driving chip 7, a driving circuit input interface third row of pins 8, a first row of pins 9 of the first bridge arm Q1 output signal and a second row of pins 10 of the second bridge arm Q2 output signal.

[0075] In the embodiment, the driving circuit substrate can be made of FR-4 plate material with a thickness of 1.6 mm, and in other embodiments, other plate materials can also be used, which will not be described here.

[0076] The first transformer unit 2 is used to raise the +15V voltage to 22.5V while achieving electrical isolation. The second transformer unit 3 is used to raise the +15V voltage to 22.5V while achieving electrical isolation. Here, the input DC +15V is taken as +15V, and the turns ratio of the transformer unit is 14:21, and in other embodiments, other values can also be used, which will not be specifically limited here.

[0077] The above-described inverter welding machine can greatly simplify and reduce the design difficulty of the silicon carbide inverter welding machine after using the silicon carbide half-bridge driving module. The driving circuit has a small size and a compact structure, and can be installed adjacent to the gate of the silicon carbide field effect tube, thereby significantly improving the reliability and anti-interference ability of the driving, and has high practical value.

[0078] In the description of the present specification, the description of the terms "some embodiments", "other embodiments", "ideal embodiments" and the like means that the specific features, structures, materials or characteristics described in conjunction with the embodiments or examples are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example.

[0079] The technical features of the above-described embodiments can be combined arbitrarily, and in order to make the description simple, not all possible combinations of the technical features in the above-described embodiments are described, however, as long as the combinations of the technical features do not exist contradictory, they should be considered as the scope of the present application.

[0080] The above-described embodiments only express several implementation manners of the present application, the description is more specific and detailed, but it should not be understood as a limitation on the scope of the application. It should be pointed out that for ordinary skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which all belong to the protection scope of the present application. Therefore, the protection scope of the present application patent should be subject to the appended claims.

Claims

1. A drive circuit characterized by comprising: The drive chip is connected with a gate of a silicon carbide power device of the inverter welder through an input signal end and an output signal end, and is connected with a gate of a silicon carbide power device of the inverter welder through a clamping signal output end. The voltage stabilizing power supply is connected with a source of a silicon carbide power device of the inverter welder through an output end. The voltage stabilizing power supply comprises:

2. The drive circuit according to claim 1, characterized by The first resistor is connected with a first end of the first capacitor and the first power signal through one end, and is connected with a first end of the voltage stabilizing tube, a second end of the first resistor, a first end of the second capacitor and the output end of the voltage stabilizing power supply through the other end. The voltage stabilizing tube is connected with a ground of a silicon carbide power device of the inverter welder through a second end and a second end of the second capacitor. The first decoupling capacitor is connected with the first pin of the drive chip and the input direct current through one end, and is grounded through the other end.

3. The drive circuit according to claim 1, characterized by The second decoupling capacitor is connected with the second pin of the drive chip and the first power signal through one end, and is connected with a ground of a silicon carbide power device of the inverter welder through the other end. The second resistor is connected with the drive signal through one end, and is connected with the input signal end of the drive chip through the other end. The third resistor is connected with the other end of the second resistor through one end, and is grounded through the other end.

4. The drive circuit according to claim 1, characterized by The power module is connected with the input direct current through an input end, and is connected with the input end of the voltage stabilizing power supply through an output end, so as to provide the first power signal for the voltage stabilizing power supply. The power module comprises: The current conversion unit is connected with the input direct current through an input end, and is used for converting the input direct current into high-frequency alternating current.

5. The drive circuit according to any one of claims 1 to 4, characterized by The transformer unit is connected with the output end of the current conversion unit through a primary side. The rectification and filtering unit is connected with a secondary side of the transformer unit through an input end, and is connected with the input end of the voltage stabilizing power supply through an output end.

6. The drive circuit according to claim 5, characterized in that, The current conversion unit comprises: The third capacitor and the fourth capacitor are connected with the input direct current through first ends, and are grounded through second ends. The current conversion chip is connected with the input direct current and the ground through input pins respectively, and is connected with the primary side of the transformer unit through output pins. The turns ratio of the transformer unit is 14:

21.

7. The drive circuit according to claim 6, characterized in that, The first bridge arm comprises a first silicon carbide power device. The second bridge arm comprises a second silicon carbide power device. The first drive circuit and the second drive circuit are the drive circuit in any one of claims 1 to 8.

8. The drive circuit of claim 6, wherein, The turn-on resistance and the turn-off resistance of the first silicon carbide power device are placed close to the first silicon carbide power device, and the turn-on resistance and the turn-off resistance of the second silicon carbide power device are placed close to the second silicon carbide power device.

9. An inverter welder characterized by, ​ ​ ​ ​ ​ ​ 10. The inverter welder of claim 9, wherein, ​

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