Large integrated chopper bridge circuit

Abstract

The utility model discloses a large-scale integrated chopper bridge circuit, which comprises an input end positive electrode / output end positive electrode, an input end negative electrode, a first chopper bridge circuit, a second chopper bridge circuit, a pilot arc bridge circuit, a floating voltage circuit, a first chopper bridge output end negative electrode, a second chopper bridge output end negative electrode and a pilot arc bridge output end negative electrode, the first chopping bridge circuit, the second chopping bridge circuit and the pilot arc bridge circuit are connected in parallel between the input end positive electrode and the input end negative electrode; the negative electrode of the output end of the first chopper bridge circuit, the negative electrode of the output end of the second chopper bridge circuit and the negative electrode of the output end of the pilot arc bridge circuit are connected through inductors. The utility model provides a large-scale integrated chopper bridge circuit, and the problem of magnetic bias of a transformer does not exist. Due to the fact that components are reasonable in layout and small in loop inductance, the power tube does not need a complex absorption circuit, even if rapid pulse control is carried out, the reliability of the power supply is not affected, and due to the fact that the bridge body power tube is high in driving frequency and externally connected with small output inductance, high-speed current control can be carried out during large-current droplet transition.

Description

Technical Field

[0001] This utility model belongs to the field of current regulation circuit technology, and in particular relates to a large integrated chopper bridge circuit. Background Technology

[0002] MIG welding typically uses an inverter power supply, which is used for high-current welding and has a single function. The power supply itself also requires an auxiliary power supply. In addition, the welding process uses high-frequency pulses, which has a significant impact on the reliability of the power supply. Summary of the Invention

[0003] To address the shortcomings of the existing technology, this invention aims to provide a large-scale integrated chopper bridge circuit that eliminates the transformer magnetization problem. Due to the reasonable component layout and low loop inductance, the power transistors do not require complex absorption circuits, and even rapid pulse control will not affect power supply reliability. Furthermore, due to the high drive frequency of the bridge power transistors and the relatively small external output inductance, high-speed current control can be achieved during high-current droplet transitions.

[0004] To achieve the above objectives, this utility model provides a large-scale integrated chopper bridge circuit, including an input positive terminal / output positive terminal, an input negative terminal, a first chopper bridge circuit, a second chopper bridge circuit, an arc bridge circuit, a floating voltage circuit, a first chopper bridge output negative terminal, a second chopper bridge output negative terminal, and an arc bridge output negative terminal; the first chopper bridge circuit, the second chopper bridge circuit, and the arc bridge circuit are connected in parallel between the input positive terminal / output positive terminal and the input negative terminal; the first chopper bridge circuit output negative terminal, the second chopper bridge circuit output negative terminal, and the arc bridge circuit output negative terminal are respectively connected through inductors; the floating voltage circuit is connected to the arc bridge circuit.

[0005] In one implementation, the first chopper bridge circuit and the second chopper bridge circuit are partially arranged in an alternating and overlapping manner.

[0006] In one implementation, the first chopper bridge circuit and the second chopper bridge circuit respectively include:

[0007] A capacitor bank, comprising multiple capacitors connected in series, is connected between the positive terminal of the input / output terminal and the negative terminal of the input.

[0008] A freewheeling diode group, the freewheeling diode group comprising multiple freewheeling diodes connected in parallel in the same direction, the cathode of the freewheeling diode group being connected to the positive terminal of the input terminal / positive terminal of the output terminal;

[0009] A switching power transistor group, comprising multiple switching power transistors connected in parallel, wherein the source of the switching power transistor group is connected to the negative input terminal, and the drain of the switching power transistor group is connected to the anode of the freewheeling diode group and serves as the negative output terminal via a connection to a corresponding heatsink; and

[0010] A one-dimensional arc power supply, wherein the arc power supply is connected between the positive input terminal / positive output terminal and the negative input terminal.

[0011] As one implementation, the arc bridge circuit includes:

[0012] A one-dimensional arc diode, wherein the cathode of the arc diode is connected to the positive terminal of the input / output terminal; and

[0013] A one-dimensional arc switch power transistor, wherein the source of the one-dimensional arc switch power transistor is connected to the negative terminal of the input terminal, and the drain of the one-dimensional arc switch power transistor is connected to the anode of the one-dimensional arc diode, and serves as the negative terminal of the output terminal of the one-dimensional arc bridge.

[0014] As one implementation, a floating voltage circuit is also included, the floating voltage circuit comprising two resistors connected in series, one resistor being connected in parallel between the source and drain of the arc-switching power transistor, and the other resistor being connected in parallel between the cathode and anode of the arc-switching diode.

[0015] In one implementation, the output terminals of the first chopper bridge circuit and the second chopper bridge circuit are respectively connected to the heat sink; the switching power transistor group and the freewheeling diode group are respectively connected to the corresponding heat sink; the heat sink is connected to the corresponding inductor.

[0016] In one implementation, the freewheeling diode groups are spaced apart on both sides of the corresponding switching power transistor groups.

[0017] In one implementation, the capacitor banks of the first chopper bridge circuit and the second chopper bridge circuit are arranged in an alternating and overlapping manner.

[0018] In one embodiment, the arc bridge circuit and the floating voltage circuit are respectively connected to the heat sink via insulating pads.

[0019] In one implementation, multiple insulating posts are connected between the heat sinks.

[0020] Because of the adoption of the above technical solution, this utility model has the following beneficial effects:

[0021] The first chopper bridge circuit, the second chopper bridge circuit, the arc-maintaining bridge circuit, and the floating voltage circuit together form an integrated chopper bridge used in MIG welding, capable of handling up to 1000A. The three integrated chopper bridges, combined through three inductors, output a more powerful current. The first and second chopper bridge circuits combine to form a larger power supply; both bridges can operate simultaneously to reach 100% of their rated current. The symmetrical layout provides better current uniformity, and the reduced loop inductance (half the current) increases the current rise rate, a characteristic beneficial to welding performance.

[0022] Using multiple low-voltage, high-current switching power transistors in parallel reduces conduction losses. Furthermore, direct contact between the switching power transistors and the heatsink ensures excellent heat dissipation. A two-path symmetrical design, using two inductors for current shunting and equalization, allows the fan to fully utilize its cooling capacity. Individual control of each path enables lower ripple current and higher control precision at low current levels. The freewheeling diodes are integrated seamlessly with the switching power transistors, reducing peak voltage during high-current operation.

[0023] This application uses a transformer to step down the voltage and then uses a secondary high current direct regulation. Due to the reasonable component layout and small circuit inductance, the power transistor does not need a complex absorption circuit. Even if fast pulse control is performed, it will not affect the reliability of the power supply. Because the bridge power transistor has a high driving frequency and a small external output inductor, high-speed current control can be performed during the high current droplet transition.

[0024] This application adopts a distributed layout, which uses two large main arc choppers arranged in an interleaved layout, and the output is connected to two inductors, and the two inductors are combined for output. This makes the ripple when operating at low current half that of a single-channel controlled power supply.

[0025] The arc-initiating power supply and floating voltage circuit of this application are beneficial for flexible arc initiation and sampling. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 A circuit diagram of a large integrated chopper bridge circuit according to an embodiment of this application;

[0028] Figure 2 This is a front view of the structure of a large integrated chopper bridge circuit according to an embodiment of this application;

[0029] Figure 3This is a top view of the structure of a large integrated chopper bridge circuit according to an embodiment of this application;

[0030] Figure 4 This is a rear view of the structure of a large integrated chopper bridge circuit according to an embodiment of this application;

[0031] Figure 5 The image shows a three-view diagram of the structure of a large integrated chopper bridge circuit according to an embodiment of this application.

[0032] Explanation of icon numbers:

[0033] 1-Input terminal positive / Output terminal positive;

[0034] 2-Input terminal negative;

[0035] 3-First chopper bridge circuit;

[0036] 4-Second chopper bridge circuit;

[0037] 5-dimensional arc bridge circuit;

[0038] 6-Floating voltage circuit;

[0039] 7- The negative terminal of the first chopper bridge output;

[0040] 8 - Negative output terminal of the second chopper bridge;

[0041] 9-dimensional arc bridge output negative terminal;

[0042] 10 - Insulating mat;

[0043] 11-First insulating post;

[0044] 12 - Second insulating post;

[0045] 13 - Third insulating post;

[0046] 14 - Fourth insulating post;

[0047] 15 - First heat sink;

[0048] 16 - Second heat sink. Detailed Implementation

[0049] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0050] In the description of this utility model, it should be noted that the terms "upper," "lower," "left," "right," "center," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this utility model and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first," "second," and "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0051] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "setting," "connection," "linking," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0052] Example 1

[0053] Please see Figure 1 According to Embodiment 1 of this utility model, a large integrated chopper bridge circuit includes an input positive terminal / output positive terminal 1, an input negative terminal 2, a first chopper bridge circuit 3, a second chopper bridge circuit 4, an arc-shaped bridge circuit 5, a floating voltage circuit 6, a first chopper bridge output negative terminal 7, a second chopper bridge output negative terminal 8, and an arc-shaped bridge output negative terminal 9. The first chopper bridge circuit 3, the second chopper bridge circuit 4, the arc-shaped bridge circuit 5, and the floating voltage circuit 6 are connected in parallel between the input positive terminal / output positive terminal 1 and the input negative terminal 2. The first chopper bridge circuit output negative terminal 7, the second chopper bridge circuit output negative terminal 8, and the arc-shaped bridge circuit output negative terminal 9 are each connected through an inductor. The input positive terminal / output positive terminal 1 serves as both an input and an output. The floating voltage circuit 6 is connected to the arc-shaped bridge circuit 5.

[0054] The first chopper bridge circuit 3 and the second chopper bridge circuit 4 each include:

[0055] A capacitor bank CA and CB, wherein the capacitor bank CA and CB comprises multiple capacitors connected in series, and the capacitor bank CA and CB are connected between the positive terminal of the input terminal / positive terminal 1 and the negative terminal of the input terminal 2. The capacitors are used to absorb voltage spikes.

[0056] A freewheeling diode group DA and DB, wherein the freewheeling diode group DA and DB includes multiple freewheeling diodes connected in parallel in the same direction, and the negative terminal of the freewheeling diode group DA and DB is connected to the positive terminal of the input terminal / positive terminal of the output terminal 1;

[0057] A switching power transistor group QA and QB comprises multiple switching power transistors connected in parallel. The source of each switching power transistor is connected to the negative input terminal 2. The drain of the switching power transistor group is connected to the anode of the freewheeling diode group DA and DB, and serves as the negative output terminal through connection to a corresponding heatsink.

[0058] In this embodiment, the one-dimensional arc power supply uses power transistors SA and SB, which are respectively connected between the gate of the switching power transistor and the negative input terminal 2.

[0059] In this embodiment, the first chopper bridge circuit 3 includes a capacitor bank CA, a freewheeling diode bank DA, and a switching power transistor bank QA. The second chopper bridge circuit 4 includes a capacitor bank CB, a freewheeling diode bank DB, and a switching power transistor bank QB.

[0060] In this embodiment, the arc bridge circuit 5 includes:

[0061] A one-dimensional arc diode DW, wherein the cathode of the one-dimensional arc diode DW is connected to the positive input terminal / positive output terminal 1; and

[0062] A one-dimensional arc switch power transistor QW, the source of which is connected to the negative input terminal 2, and the drain of which is connected to the anode of the arc diode DW, and serves as the negative output terminal 9 of the arc bridge.

[0063] In this embodiment, a floating voltage circuit 6 is also included. The floating voltage circuit 6 includes two resistors RF1 and RF2 connected in series. The resistor RF2 is connected in parallel between the source and drain of the arc-suspension switching power transistor QW, and the resistor RF1 is connected in parallel across the arc-suspension diode DW.

[0064] The first chopper bridge circuit 3, the second chopper bridge circuit 4, the arc-maintaining bridge circuit 5, and the floating voltage circuit 6 work together to form an integrated chopper bridge capable of handling up to 1000A used in MIG welding. The three integrated chopper bridges, combined through three inductors, output a more powerful current. The first chopper bridge circuit 3 and the second chopper bridge circuit 4 each combine through an inductor to form a larger power supply. With both bridges operating simultaneously, they can reach 100% of their rated current. The symmetrical layout provides better current uniformity, and the reduced loop inductance (half the current) increases the current rise rate, a characteristic beneficial to welding performance.

[0065] The arc bridge circuit 5 can generate a current of less than 50A, and the floating voltage circuit 6 can generate an open-circuit voltage when all bridges are not working, without the need for an additional power supply. After the load is short-circuited, the open-circuit voltage disappears, and the power supply outputs only a small current of less than 50mA.

[0066] The design challenges of this application include:

[0067] 1. The problem of parallel current equalization of multiple power transistors

[0068] 2. Voltage spike problem under high current operation: Because low-voltage power transistors are used, the voltage peak tolerance is low, and a large operating current can easily generate voltage spikes of more than 200V.

[0069] 3. Due to the large current, the circuit connection requirements are high. The connection points must not generate heat.

[0070] 4. Although the operating current is very high—generally 1000A for MIG welding and 2000A for submerged arc welding, while resistance RF welding requires 10000A—the size and weight of the bridge body cannot be too large; it must be smaller than that of an inverter welding machine of equivalent power.

[0071] To address the aforementioned design challenges, this application adopts the following design approach:

[0072] Using multiple low-voltage, high-current switching power transistors in parallel reduces conduction losses. A two-path symmetrical design, with inductors for current shunting and equalization, allows the fan to fully utilize its cooling capacity. Furthermore, individual control of each path enables lower ripple current and higher control precision at low current levels. The freewheeling diode is integrated seamlessly with the switching power transistors, reducing peak voltage during high-current operation.

[0073] This application also has the following beneficial effects:

[0074] This application uses a transformer to step down the voltage and then uses a secondary high current direct regulation. Since there is no transformer bias problem, even if a fast pulse control is performed, it will not affect the reliability of the power supply. Therefore, high-speed current control can be performed when the molten droplet is in a high-current state.

[0075] This application adopts a distributed layout. After arranging two large main arc choppers in an alternating layout, the output terminal 1- of the first chopper bridge and the output terminal 2- of the second chopper bridge are connected through inductors respectively. This makes the ripple when operating at low current half that of a single-channel controlled power supply.

[0076] The arc power supplies SA and SB and the floating voltage circuits RF1 and RF2 in this application are beneficial for flexible arc initiation and sampling.

[0077] By connecting multiple power transistors in parallel, the thermal resistance and wiring resistance RF are reduced, which can reduce conduction losses. In this embodiment, multiple low-voltage high-current MOSFETs / IGBTs are connected in parallel without using modules, which can achieve higher overall efficiency of power transistors and reduce costs.

[0078] The freewheeling diode and the switching power transistor are fully integrated and distributed, which reduces the peak voltage during high current operation, reduces the impact on components, and improves the stability of the circuit.

[0079] An arc bridge circuit 5 and a floating voltage circuit 6 are integrated into the first chopper bridge circuit 3 and the second chopper bridge circuit 4 as auxiliary power sources for flexible arc initiation, avoiding the impact of full pulse width and high current arc initiation in conventional welding, and the bursting of the molten pool.

[0080] Example 2

[0081] Please see Figures 1-4 The large integrated chopper bridge circuit of Embodiment 2 of this utility model has a structure that is basically the same as that of Embodiment 1. The difference is that the first chopper bridge circuit 3 and the second chopper bridge circuit 4 are arranged in an alternating and overlapping manner.

[0082] In this embodiment, the heat sink includes a first heat sink 15 and a second heat sink 16.

[0083] The output terminals of the first chopper bridge circuit 3 and the second chopper bridge circuit 4 are respectively equipped with a first heat sink 15 as the negative terminal 7 of the first chopper bridge output terminal and a second heat sink 16 as the negative terminal 8 of the second chopper bridge output terminal; the switching power transistor group DA and the freewheeling diode group QA are respectively connected to the corresponding first heat sink 15; the switching power transistor group DB and the freewheeling diode group QB are respectively connected to the corresponding second heat sink 16; the first heat sink 15 and the second heat sink 16 are connected to the corresponding inductors.

[0084] The freewheeling diode group DA is spaced apart on both sides of the corresponding switching power transistor group QA.

[0085] The freewheeling diode group DB is spaced apart on both sides of the corresponding switching power transistor group QB.

[0086] The capacitor banks QA and QB of the first chopper bridge circuit 3 and the second chopper bridge circuit 4 are arranged in an alternating and overlapping manner.

[0087] The switching power transistor is directly attached to the heatsink, resulting in good heat dissipation. The first chopper bridge circuit 3 and the second chopper bridge circuit 4 are partially staggered and overlapped. The staggered distribution of the first chopper bridge circuit 3 and the second chopper bridge circuit 4 allows them to be interlocked to reduce space occupation and form a centralized heat dissipation channel. This allows a single fan to be used for heat dissipation, ensuring smooth heat dissipation and enabling the fan to fully utilize its heat dissipation capacity.

[0088] Example 3

[0089] The large integrated chopper bridge circuit of Embodiment 3 of this utility model has a structure that is basically the same as that of Embodiment 2. The difference is that the arc bridge circuit 5 and the floating voltage circuit 6 are connected to the heat sink through the insulating pad 10.

[0090] Example 4

[0091] A large integrated chopper bridge circuit according to Embodiment 4 of this utility model has a structure that is basically the same as that of Embodiment 3, except that a plurality of insulating posts are connected between the first heat sink 15 and the second heat sink 16. In this embodiment, the insulating posts include a first insulating post 11, a second insulating post 12, a third insulating post 13 and a fourth insulating post 14, which are respectively connected between the four apex corners of the first heat sink 15 and the second heat sink 16.

[0092] The present invention has been described in detail above with reference to the accompanying drawings and embodiments. Those skilled in the art can make various modifications to the present invention based on the above description. Therefore, certain details in the embodiments should not be construed as limiting the present invention, and the scope of protection of the present invention shall be defined by the appended claims.

Claims

1. A large-scale integrated chopper bridge circuit, characterized in that, It includes an input positive terminal / output positive terminal, an input negative terminal, a first chopper bridge circuit, a second chopper bridge circuit, an arc bridge circuit, a floating voltage circuit, and the output negative terminals of the first chopper bridge, the second chopper bridge, and the arc bridge. The first chopper bridge circuit, the second chopper bridge circuit, and the arc bridge circuit are connected in parallel between the input positive terminal / output positive terminal and the input negative terminal. The output negative terminals of the first chopper bridge circuit, the second chopper bridge circuit, and the arc bridge circuit are connected through inductors. The floating voltage circuit is connected to the arc bridge circuit.

2. The large integrated chopper bridge circuit according to claim 1, characterized in that, The first chopper bridge circuit and the second chopper bridge circuit are arranged in an alternating and overlapping manner.

3. The large integrated chopper bridge circuit according to claim 1, characterized in that, The first chopper bridge circuit and the second chopper bridge circuit each include: A capacitor bank, comprising multiple capacitors connected in series, is connected between the positive terminal of the input / output terminal and the negative terminal of the input. A freewheeling diode group, the freewheeling diode group comprising multiple freewheeling diodes connected in parallel in the same direction, the cathode of the freewheeling diode group being connected to the positive terminal of the input terminal / positive terminal of the output terminal; A switching power transistor group, comprising multiple switching power transistors connected in parallel, wherein the source of the switching power transistor group is connected to the negative input terminal, and the drain of the switching power transistor group is connected to the anode of the freewheeling diode group and serves as the negative output terminal via a connection to a corresponding heatsink; and A one-dimensional arc power supply, wherein the arc power supply is connected between the positive input terminal / positive output terminal and the negative input terminal.

4. The large integrated chopper bridge circuit according to claim 3, characterized in that, The arc bridge circuit includes: A one-dimensional arc diode, wherein the cathode of the arc diode is connected to the positive terminal of the input / output terminal; and A one-dimensional arc switch power transistor, wherein the source of the one-dimensional arc switch power transistor is connected to the negative terminal of the input terminal, and the drain of the one-dimensional arc switch power transistor is connected to the anode of the one-dimensional arc diode, and serves as the negative terminal of the output terminal of the one-dimensional arc bridge.

5. The large integrated chopper bridge circuit according to claim 4, characterized in that, It also includes a floating voltage circuit, which includes two resistors connected in series. One resistor is connected in parallel between the source and drain of the arc switching power transistor, and the other resistor is connected in parallel between the cathode and anode of the arc diode.

6. The large integrated chopper bridge circuit according to any one of claims 3 to 5, characterized in that, The output terminals of the first chopper bridge circuit and the second chopper bridge circuit are respectively connected to the heat sink; the switching power transistor group and the freewheeling diode group are respectively connected to the corresponding heat sink; the heat sink is connected to the corresponding inductor.

7. The large integrated chopper bridge circuit according to claim 6, characterized in that, The freewheeling diode groups are arranged at intervals on both sides of the corresponding switching power transistor groups.

8. The large integrated chopper bridge circuit according to claim 6, characterized in that, The capacitor banks of the first chopper bridge circuit and the second chopper bridge circuit are arranged in an alternating and overlapping manner.

9. The large integrated chopper bridge circuit according to claim 6, characterized in that, The arc bridge circuit and the floating voltage circuit are respectively connected to the heat sink via insulating pads.

10. The large integrated chopper bridge circuit according to claim 6, characterized in that, Multiple insulating posts are connected between the heat sinks.

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