Multi-inverter welding machine circuit and welding machine

Abstract

A multi-inverter welding machine circuit and a welding machine, wherein the multi-inverter welding machine circuit converts the connected external alternating current into direct current by adopting a front rectifier circuit, a drive circuit, a plurality of IGBT inverters and a rear rectifier circuit, and then converts the multiple target alternating currents into total target direct currents by using the rear rectifier circuit after the alternating currents are converted by the plurality of IGBT inverters and outputs the total direct currents to an output end, the power loss of the IGBT inverter is smaller than that of the inverter using MOS tubes, and the volume of the IGBT inverter is smaller than that of the inverter using MOS tubes, thereby realizing the reduction of the volume of the welding machine and the reduction of the power loss, and solving the problems of large volume and large power loss of the welding machine in the traditional welding machine.

Description

Technical Field

[0001] The present application belongs to the technical field of welding machine manufacturing, and in particular relates to a multi-inverter welding machine circuit and a welding machine. Background Art

[0002] At present, traditional welding machines generally use inverters composed of MOS tubes as power conversion devices, but the start-up and operation of the welding machine require a large amount of power to maintain, and the power loss of MOS tubes is large, so a large number of MOS tubes need to be added to the inverter to achieve the corresponding output power. Although the addition of a large number of MOS tubes increases the output power overall, its total power loss also increases; and because of the large number of MOS tubes, the size of the whole machine is very large.

[0003] Therefore, the conventional welding machine has the problems of large size and large power loss. Summary of the invention

[0004] The purpose of the present application is to provide a multi-inverter welding machine circuit and a welding machine, aiming to solve the problems of large size, large power loss and unconcentrated arc capacity in traditional welding machines.

[0005] A first aspect of an embodiment of the present application provides a multi-inverter welding machine circuit, wherein the output end of the multi-inverter welding machine circuit includes a positive electrode and a negative electrode, and further includes:

[0006] A pre-rectifier circuit, used for receiving external AC power and converting the external AC power into DC power;

[0007] Control circuit;

[0008] A driving circuit, the driving circuit is connected to the control circuit, and the driving circuit is used to output a plurality of driving signals under the control of the control circuit;

[0009] a plurality of IGBT inverters, each of which is connected to the pre-rectifier circuit and the drive circuit, and is connected in parallel, and each of which is used to convert the DC power into a corresponding target AC power under the control of the corresponding drive signal; and

[0010] A post-rectifier circuit is connected to the multiple IGBT inverters and the positive electrode, and is used to convert the target alternating current output by the multiple IGBT inverters into a target direct current, and add the multiple target direct currents in parallel to form a total target direct current and output it to the positive electrode; or is used to add the target alternating current output by the multiple IGBT inverters in parallel, convert it into a total target direct current and output it to the positive electrode.

[0011] In one embodiment, the IGBT inverter comprises:

[0012] A filter circuit, connected to the pre-rectifier circuit, for filtering out clutter interference of the direct current;

[0013] An IGBT inverter circuit, connected to the filter circuit, configured to convert the DC power into a first AC power; and

[0014] A voltage conversion circuit is connected to the IGBT inverter circuit and the post-rectifier circuit, and is used for converting the first alternating current into the target alternating current, and outputting the target alternating current to the rectifier circuit.

[0015] In one embodiment, the IGBT inverter circuit includes a first capacitor, a second capacitor, a first IGBT thyristor, a second IGBT thyristor, a third IGBT thyristor and a fourth IGBT thyristor, the first end of the first capacitor, the first end of the first IGBT thyristor and the first end of the second IGBT thyristor are commonly connected to the first output end of the filter circuit, the second end of the first capacitor and the first end of the second capacitor are commonly connected to the second input end of the voltage conversion circuit, the second end of the first IGBT thyristor, the second end of the second IGBT thyristor, the first end of the third IGBT thyristor and the first end of the fourth IGBT thyristor are commonly connected to the first input end of the voltage conversion circuit, the second end of the second capacitor is connected to the second end of the third IGBT thyristor and the second end of the fourth IGBT thyristor, the control end of the first IGBT thyristor and the control end of the second IGBT thyristor are connected to the first output end of the drive circuit, and the control end of the third IGBT thyristor and the control end of the fourth IGBT thyristor are connected to the second output end of the drive circuit.

[0016] In one embodiment, the IGBT inverter circuit further includes a first resistor, a second resistor, a third resistor and a fourth resistor, the first end of the first resistor is connected to the first end of the first capacitor, the second end of the first resistor is connected to the first end of the second resistor, the second end of the second resistor is connected to the first end of the third resistor and the second end of the first capacitor, the second end of the third resistor is connected to the first end of the fourth resistor, and the second end of the fourth resistor is connected to the second end of the second capacitor.

[0017] In one embodiment, the voltage conversion circuit includes: a first transformer, a primary winding of the first transformer is connected to the IGBT inverter circuit, and a secondary winding of the first transformer is connected to the post-rectifier circuit.

[0018] In one embodiment, an isolation detection circuit is also included. The isolation detection circuit is connected in series between the IGBT inverter circuit and the voltage conversion circuit. The isolation detection circuit is connected to the control circuit. The isolation detection circuit is used to collect the current of the first alternating current output by the IGBT inverter circuit, and isolate the current of the first alternating current and output it to the control circuit.

[0019] In one embodiment, the isolation detection circuit comprises: a current transformer, wherein a primary side of the current transformer is connected between the IGBT inverter circuit and the voltage conversion circuit, and a secondary side of the current transformer is connected to the control circuit.

[0020] In one embodiment, the rectifier circuit comprises:

[0021] a sub-rectifier circuit, wherein the input end of the sub-rectifier circuit is connected to the first output ends of the plurality of IGBT inverters, the two output ends of the sub-rectifier circuit are connected to the positive electrode and the negative electrode respectively, and the sub-rectifier circuit is used to add the target alternating current output by the plurality of IGBT inverters in parallel, convert it into the total target direct current and output it to the positive electrode; or

[0022] A plurality of sub-rectifier circuits, wherein the input end of each sub-rectifier circuit is connected to the first output end of each IGBT inverter, the first output ends of each sub-rectifier circuit are connected to the positive electrode, and the second output ends of each sub-rectifier circuit are connected to the negative electrode. The plurality of sub-rectifier circuits are respectively used to convert the target alternating current output by the correspondingly connected IGBT inverter into a target direct current, and then add the plurality of target direct currents to form a total target direct current and output it to the positive electrode.

[0023] In one embodiment, the sub-rectifier circuit includes: a first diode, a second diode, a third diode, a fourth diode and a first inductor, the anode of the first diode and the anode of the second diode are connected in parallel to the first output end of the IGBT inverter, the anode of the third diode and the anode of the fourth diode are connected in parallel to the second output end of the IGBT inverter, the cathode of the first diode, the cathode of the second diode, the cathode of the third diode and the cathode of the fourth diode are connected in common to the anode, the first end of the first inductor is connected to the neutral line end of the IGBT inverter, and the second end of the first inductor is connected to the cathode.

[0024] A second aspect of the embodiment of the present application provides a welding machine, comprising:

[0025] a housing; and

[0026] As described in the first aspect of the embodiment of the present application, the multi-inverter welding circuit is arranged in the housing.

[0027] The above-mentioned multi-inverter welding machine circuit converts the connected external AC power into DC power by adopting a front rectifier circuit, a drive circuit, multiple IGBT inverters and a rear rectifier circuit, and then converts the multiple target AC power into a total target DC power by using the rear rectifier circuit to output it to the positive electrode. The power loss of the IGBT inverter is smaller than that of the inverter using MOS tube, and the volume of the IGBT inverter is smaller than that of the inverter using MOS tube, thereby reducing the volume of the welding machine and reducing the power loss, and solving the problems of large volume and large power loss of the traditional welding machine. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 A circuit diagram of a multi-inverter welding machine circuit provided in an embodiment of the present application;

[0029] Figure 2 for Figure 1 A circuit diagram of an IGBT inverter of a multi-inverter welding machine circuit shown;

[0030] Figure 3 for Figure 2 Another circuit schematic diagram of an IGBT inverter of a multi-inverter welding machine circuit shown;

[0031] Figure 4 for Figure 1 The circuit diagram of the finishing circuit of the multi-inverter welding machine circuit shown;

[0032] Figure 5 for Figure 1 Another circuit schematic diagram of the finishing circuit of the multi-inverter welding machine circuit shown;

[0033] Figure 6 This is a partial example circuit schematic of the multi-inverter welding machine circuit shown above. DETAILED DESCRIPTION

[0034] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0035] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0036] It should be understood that the orientation or position relationship indicated by terms such as "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to 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 application.

[0037] 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. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0038] Figure 1 The structure diagram of the multi-inverter welding machine circuit provided in the embodiment of the present application is shown. For the convenience of explanation, only the part related to the present embodiment is shown, which is described in detail as follows:

[0039] The multi-inverter welding machine circuit in this embodiment includes a positive electrode 20 and a negative electrode 30, and also includes: a pre-rectifier circuit 100, a drive circuit 200, a plurality of IGBT inverters 300 and a post-rectifier circuit 400, wherein the plurality of IGBT inverters 300 are respectively connected to the pre-rectifier circuit 100 and the drive circuit 200, and the plurality of IGBT inverters 300 are connected in parallel, and the post-rectifier circuit 400 is connected to the plurality of IGBT inverters 300 and the positive electrode 20. The pre-rectifier circuit 100 is used to access external AC power and convert the external AC power into DC power. The drive circuit 200 is used to output a plurality of drive signals. The plurality of IGBT inverters 300 are respectively used to convert DC power into corresponding target AC power under the control of corresponding drive signals. The post-rectifier circuit 400 is used to convert the target AC power outputted by the plurality of IGBT inverters 300 into the target DC power, and add the plurality of target DC power in parallel to form the total target DC power and output it to the positive electrode 20; or to add the target AC power outputted by the plurality of IGBT inverters 300 in parallel, convert it into the total target DC power and output it to the positive electrode 20. 10 in the figure is a partial multi-inverter welding machine circuit including the pre-rectifier circuit 100, the drive circuit 200, the plurality of IGBT inverters 300 and the post-rectifier circuit 400.

[0040] It is understandable that the pre-rectifier circuit 100 and the post-rectifier circuit 400 may be composed of rectifier devices or circuits, such as rectifier diodes, or rectifier bridges, etc. The drive circuit 200 may be composed of a bridge arm driver chip; the control circuit 210 may be composed of a microprocessor, the bridge arm driver chip may be integrated into the microprocessor, or may be independently arranged outside the microprocessor, and the microprocessor may be a single-chip microcomputer, etc.

[0041] It is understandable that the external AC power may be a mains power supply, or an AC power output by an external AC power supply. The driving signal may be a pulse width modulation signal, or a level signal.

[0042] The multi-inverter welding machine circuit in this embodiment adopts a pre-rectifier circuit 100, a control circuit 210, a drive circuit 200, a plurality of IGBT inverters 300 and a post-rectifier circuit 400 to convert the connected external AC power into DC power, and then converts the multiple target AC power into a total target DC power by using the post-rectifier circuit 400 to output to the positive electrode 20. The power loss of the IGBT inverter 300 is smaller than that of the inverter using the MOS tube, and the volume of the IGBT inverter 300 is smaller than that of the inverter using the MOS tube, thereby reducing the volume of the welding machine and reducing the power loss, and solving the problems of large volume and large power loss of the traditional welding machine.

[0043] See also Figure 2 In one embodiment, an IGBT inverter 300 includes: a filter circuit 310, an IGBT inverter circuit 320 and a voltage conversion circuit 330. The filter circuit 310 is connected to the pre-rectifier circuit 100, the IGBT inverter circuit 320 is connected to the input end of the filter circuit 310 and the voltage conversion circuit 330, and the output end of the voltage conversion circuit 330 is connected to the post-rectifier circuit 400. The filter circuit 310 is used to filter out the clutter interference of the direct current. The IGBT inverter circuit 320 is used to convert the direct current into the first alternating current. The voltage conversion circuit 330 is used to convert the first alternating current into the target alternating current, and output the target alternating current to the rectifier circuit.

[0044] It is understandable that the filter circuit 310 may be composed of components such as filter capacitors, the IGBT inverter circuit 320 may be composed of inverter bridge arms composed of IGBT thyristors, and the voltage conversion circuit 330 may be composed of transformers, etc.

[0045] It can be understood that the IGBT inverter 300 in this embodiment realizes the inversion and voltage conversion of direct current by adopting the filter circuit 310, the IGBT inverter circuit 320 and the voltage conversion circuit 330. The circuit structure is simple, and due to the reduction of clutter interference and the use of the inverter circuit composed of IGBT devices, it achieves low power loss and high conversion efficiency.

[0046] It can be understood that the configuration of other IGBT inverters 300 may be consistent with the configuration of the IGBT inverter 300 in this embodiment.

[0047] In one embodiment, the filter circuit 310 includes a plurality of capacitors connected in parallel. Figure 6 The filter circuit 310 includes a capacitor C5, a capacitor C6 and a capacitor C7, and the capacitor C5, the capacitor C6 and the capacitor C7 are connected in parallel.

[0048] It can be understood that the capacitors in this embodiment are polar capacitors, the positive electrodes of the polar capacitors are connected to the positive output terminal of the pre-rectifier circuit 100 , and the negative terminals of the polar capacitors are connected to the negative output terminal of the pre-rectifier circuit 100 .

[0049] See also Figure 6 In one embodiment, the IGBT inverter circuit 320 includes a first capacitor C1, a second capacitor C2, a first IGBT thyristor Q1, a second IGBT thyristor Q2, a third IGBT thyristor Q3 and a fourth IGBT thyristor Q4. The first end of the first capacitor C1, the first end of the first IGBT thyristor Q1 and the first end of the second IGBT thyristor Q2 are commonly connected to the first output end of the filter circuit 310. The second end of the first capacitor C1 and the first end of the second capacitor C2 are commonly connected to the second input end of the voltage conversion circuit 330. The second end of the first IGBT thyristor Q1, the second IGBT thyristor Q2 and the third IGBT thyristor Q3 are commonly connected to the first output end of the filter circuit 310. The second end of the third IGBT thyristor Q2, the first end of the third IGBT thyristor Q3, and the first end of the fourth IGBT thyristor Q4 are connected to the first input end of the voltage conversion circuit 330, the second end of the second capacitor C2 is connected to the second end of the third IGBT thyristor Q3 and the second end of the fourth IGBT thyristor Q4, the control end of the first IGBT thyristor Q1 and the control end of the second IGBT thyristor Q2 are connected to the first output end of the drive circuit 200, and the control end of the third IGBT thyristor Q3 and the control end of the fourth IGBT thyristor Q4 are connected to the second output end of the drive circuit 200.

[0050] It can be understood that the first capacitor C1 and the second capacitor C2 in this embodiment can be monolithic capacitors or ceramic capacitors.

[0051] It can be understood that the IGBT inverter circuit 320 in this embodiment realizes the inversion of DC to AC by using the first capacitor C1, the second capacitor C2, the first IGBT thyristor Q1, the second IGBT thyristor Q2, the third IGBT thyristor Q3 and the fourth IGBT thyristor Q4, and the power loss of the IGBT thyristor is smaller than that of the field effect tube used in the traditional inverter, thereby improving the output power of the IGBT inverter circuit 320 compared with the traditional welding machine inverter. Under the same output power, the use of power devices is reduced, and the volume and total power loss of the welding machine are reduced.

[0052] See also Figure 6 In one embodiment, the IGBT inverter circuit 320 further includes a first resistor R1, a second resistor R2, a third resistor R3 and a fourth resistor R4, a first end of the first resistor R1 is connected to a first end of the first capacitor C1, a second end of the first resistor R1 is connected to a first end of the second resistor R2, a second end of the second resistor R2 is connected to a first end of the third resistor R3 and a second end of the first capacitor C1, a second end of the third resistor R3 is connected to a first end of the fourth resistor R4, and a second end of the fourth resistor R4 is connected to a second end of the second capacitor C2.

[0053] It can be understood that the IGBT inverter circuit 320 in this embodiment improves the ability of the IGBT inverter circuit 320 to isolate DC signals by adding the first resistor R1, the second resistor R2, the third resistor R3 and the fourth resistor R4, and when power is required to be cut off, the first resistor R1, the second resistor R2, the third resistor R3 and the fourth resistor R4 are used as discharge resistors to speed up the discharge of the electric energy stored in the first capacitor C1 and the second capacitor C2, so as to ensure that the multi-inverter welding machine circuit can be powered off in time to avoid damage to the welding machine due to power-off delay.

[0054] See also Figure 6 In one embodiment, the voltage conversion circuit 330 includes: a first transformer T1 , a primary winding of the first transformer T1 is connected to the IGBT inverter circuit 320 , and a secondary winding of the first transformer T1 is connected to the post-rectifier circuit 400 .

[0055] It is understandable that the first transformer T1 may be a step-down transformer, which is used to reduce the voltage of the first alternating current to a target voltage. Optionally, the first transformer T1 may be a high-frequency main transformer.

[0056] See also Figure 3In one embodiment, it also includes an isolation detection circuit 340, which is connected in series between the IGBT inverter circuit 320 and the voltage conversion circuit 330. The isolation detection circuit 340 is connected to the control circuit 210. The isolation detection circuit 340 is used to collect the current of the first alternating current output by the IGBT inverter circuit 320, and isolate the current of the first alternating current and output it to the control circuit 210.

[0057] It is understandable that the isolation detection circuit 340 may be composed of isolation devices, such as a current sensor, a photocoupler, etc. The control circuit 210 may adjust the control of the driving circuit 200 according to the detection signal.

[0058] The multi-inverter welding machine circuit in this embodiment, by adding an isolation detection circuit 340, realizes current collection of the first alternating current output by the IGBT inverter circuit 320 and isolates and outputs it to the control circuit 210, thereby avoiding mutual interference of signals.

[0059] See also Figure 6 In one embodiment, the isolation detection circuit 340 includes: a current transformer T2 , wherein the primary side of the current transformer T2 is connected between the IGBT inverter circuit 320 and the voltage conversion circuit 330 , and the secondary side of the current transformer T2 is connected to the control circuit 210 .

[0060] See also Figure 4 In one embodiment, the rectifier circuit includes: a sub-rectifier circuit 410, the input end of the sub-rectifier circuit 410 is connected to the first output end of the multiple IGBT inverters 300, and the two output ends of the sub-rectifier circuit 410 are respectively connected to the positive electrode 20 and the negative electrode 30. The sub-rectifier circuit 410 is used to add the target alternating current output by the multiple IGBT inverters 300 in parallel, convert it into a total target direct current and output it to the positive electrode 20.

[0061] See also Figure 5 In one embodiment, the rectifier circuit includes: a plurality of sub-rectifier circuits 410, the input end of each sub-rectifier circuit 410 is connected to the first output end of each IGBT inverter 300, the first output ends of each sub-rectifier circuit 410 are connected to the positive electrode 20, and the second output ends of each sub-rectifier circuit 410 are connected to the negative electrode 30. The plurality of sub-rectifier circuits 410 are respectively used to convert the target alternating current output by the correspondingly connected IGBT inverter 300 into a target direct current, and then add the plurality of target direct currents to form a total target direct current and output it to the positive electrode 20.

[0062] It can be understood that when the rectifier circuit includes only one sub-rectifier circuit 410, the target AC power output by each IGBT inverter 300 is added at the input end of the rectifier circuit and then converted into the total target DC power by the rectifier circuit. When the rectifier circuit includes multiple sub-rectifier circuits 410, one sub-rectifier circuit 410 corresponds to one IGBT inverter 300, and the target AC power output by one IGBT inverter 300 is converted into the target DC power by one sub-rectifier circuit 410. The output ends of the multiple sub-rectifier circuits 410 are connected, that is, the multiple target DC power is added at the connection point of the output ends of the multiple sub-rectifier circuits 410 and converted into the total target DC power.

[0063] See also Figure 6 In one embodiment, the sub-rectifier circuit 410 includes a first diode D1, a second diode D2, a third diode D3, a fourth diode D4 and a first inductor L1, the anode of the first diode D1 and the anode of the second diode D2 are connected in parallel to the first output terminal of the IGBT inverter 300, the anode of the third diode D3 and the anode of the fourth diode D4 are connected in parallel to the second output terminal of the IGBT inverter 300, the cathode of the first diode D1, the cathode of the second diode D2, the cathode of the third diode D3 and the cathode of the fourth diode D4 are connected to the anode 20, the first end of the first inductor L1 is connected to the neutral line end of the IGBT inverter 300, and the second end of the first inductor L1 is connected to the cathode 30.

[0064] It can be understood that the sub-rectifier circuit 410 is connected to the voltage conversion circuit 330 of the IGBT inverter 300. Specifically, the positive electrode of the first diode D1 and the positive electrode of the second diode D2 are connected to the first output end of the secondary winding of the first transformer T1, and the positive electrode of the third diode D3 and the positive electrode of the fourth diode D4 are connected to the second output end of the secondary winding of the first transformer T1.

[0065] Optionally, the sub-rectifier circuit 410 further includes a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a third capacitor C3 and a fourth capacitor C4. The fifth resistor R5, the sixth resistor R6 and the third capacitor C3 are connected in parallel and then connected in parallel with the first diode D1; the seventh resistor R7, the eighth resistor R8 and the fourth capacitor C4 are connected in parallel and then connected in parallel with the third diode D3.

[0066] Optionally, the sub-rectifier circuit 410 further includes an isolation resistor, which is connected between the positive electrode 20 and the negative electrode 30 .

[0067] A second aspect of the embodiments of the present application provides a welding machine, comprising: a housing and a multi-inverter welding machine circuit as in the first aspect of the embodiments of the present application, wherein the multi-inverter welding machine circuit is disposed in the housing.

[0068] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A multi-inverter welding machine circuit, wherein the output end of the multi-inverter welding machine circuit includes a positive electrode and a negative electrode, characterized in that: The multi-inverter welding machine circuit also includes: A pre-rectifier circuit, used for receiving external AC power and converting the external AC power into DC power; Control circuit; A driving circuit, the driving circuit is connected to the control circuit, and the driving circuit is used to output a plurality of driving signals under the control of the control circuit; a plurality of IGBT inverters, each of which is connected to the pre-rectifier circuit and the drive circuit, and is connected in parallel, and each of which is used to convert the DC power into a corresponding target AC power under the control of the corresponding drive signal; and A post-rectifier circuit is connected to the plurality of IGBT inverters and the positive electrode, and is used to convert the target alternating current output by the plurality of IGBT inverters into a target direct current, and add the plurality of target direct currents in parallel to form a total target direct current, and then output it to the positive electrode; or is used to add the target alternating current output by the plurality of IGBT inverters in parallel, and then convert it into a total target direct current, and then output it to the positive electrode; The IGBT inverter comprises: A filter circuit, connected to the pre-rectifier circuit, for filtering out clutter interference of the direct current; An IGBT inverter circuit, connected to the filter circuit, configured to convert the DC power into a first AC power; and a voltage conversion circuit, connected to the IGBT inverter circuit and the post-rectifier circuit, configured to convert the first alternating current into the target alternating current, and output the target alternating current to the rectifier circuit; The IGBT inverter circuit comprises a first capacitor, a second capacitor, a first IGBT thyristor, a second IGBT thyristor, a third IGBT thyristor and a fourth IGBT thyristor, wherein the first end of the first capacitor, the first end of the first IGBT thyristor and the first end of the second IGBT thyristor are connected to the first output end of the filter circuit, the second end of the first capacitor and the first end of the second capacitor are connected to the second input end of the voltage conversion circuit, the second end of the first IGBT thyristor, the second end of the second IGBT thyristor, the first end of the third IGBT thyristor and the first end of the fourth IGBT thyristor are connected to the first input end of the voltage conversion circuit, the second end of the second capacitor is connected to the second end of the third IGBT thyristor and the second end of the fourth IGBT thyristor, the control end of the first IGBT thyristor and the control end of the second IGBT thyristor are connected to the first output end of the drive circuit, and the control end of the third IGBT thyristor and the control end of the fourth IGBT thyristor are connected to the second output end of the drive circuit; The multi-inverter welding machine circuit also includes an isolation detection circuit, which is connected in series between the IGBT inverter circuit and the voltage conversion circuit. The isolation detection circuit is connected to the control circuit. The isolation detection circuit is used to collect the current of the first alternating current output by the IGBT inverter circuit, and isolate the current of the first alternating current and output it to the control circuit.

2. The multi-inverter welding machine circuit according to claim 1, characterized in that: The IGBT inverter circuit also includes a first resistor, a second resistor, a third resistor and a fourth resistor. The first end of the first resistor is connected to the first end of the first capacitor, the second end of the first resistor is connected to the first end of the second resistor, the second end of the second resistor is connected to the first end of the third resistor and the second end of the first capacitor, the second end of the third resistor is connected to the first end of the fourth resistor, and the second end of the fourth resistor is connected to the second end of the second capacitor.

3. The multi-inverter welding machine circuit according to claim 1, characterized in that: The voltage conversion circuit includes: a first transformer, a primary winding of the first transformer is connected to the IGBT inverter circuit, and a secondary winding of the first transformer is connected to the post-rectifier circuit.

4. The multi-inverter welding machine circuit according to claim 1, characterized in that: The isolation detection circuit comprises: a current transformer, wherein a primary side of the current transformer is connected between the IGBT inverter circuit and the voltage conversion circuit, and a secondary side of the current transformer is connected to the control circuit.

5. The multi-inverter welding machine circuit according to any one of claims 1 to 4, characterized in that: The post-rectifier circuit comprises: a sub-rectifier circuit, wherein the input end of the sub-rectifier circuit is connected to the first output ends of the plurality of IGBT inverters, the two output ends of the sub-rectifier circuit are connected to the positive electrode and the negative electrode respectively, and the sub-rectifier circuit is used to add the target alternating current output by the plurality of IGBT inverters in parallel, convert it into the total target direct current and output it to the positive electrode; or A plurality of sub-rectifier circuits, wherein the input end of each sub-rectifier circuit is connected to the first output end of each IGBT inverter, the first output ends of each sub-rectifier circuit are connected to the positive electrode, and the second output ends of each sub-rectifier circuit are connected to the negative electrode. The plurality of sub-rectifier circuits are respectively used to convert the target alternating current output by the correspondingly connected IGBT inverter into a target direct current, and then add the plurality of target direct currents to form a total target direct current and output it to the positive electrode.

6. The multi-inverter welding machine circuit as claimed in claim 5, characterized in that: The sub-rectifier circuit includes: a first diode, a second diode, a third diode, a fourth diode and a first inductor, the anode of the first diode and the anode of the second diode are connected in parallel to the first output end of the IGBT inverter, the anode of the third diode and the anode of the fourth diode are connected in parallel to the second output end of the IGBT inverter, the cathode of the first diode, the cathode of the second diode, the cathode of the third diode and the cathode of the fourth diode are connected to the anode in common, the first end of the first inductor is connected to the neutral line end of the IGBT inverter, and the second end of the first inductor is connected to the cathode.

7. A welding machine, characterized in that: include: case; and The multi-inverter welding machine circuit according to any one of claims 1 to 6, wherein the multi-inverter welding machine circuit is arranged in the housing.

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