A multi-electrode welding arc power source for realizing various welding processes

Abstract

This disclosure provides a multi-electrode welding arc power supply for implementing various welding processes, comprising: a DC constant voltage source, a first full-bridge module, a second full-bridge module, four inductors, eight output terminals, a drive circuit module, and a control circuit module. By independently configuring the eight electrode output terminals, this disclosure can simultaneously output up to four controllable constant DC currents, four controllable pulse currents, or up to two controllable AC currents, enabling combinations of various welding processes. This effectively improves the coordination and stability of the outputs between the electrodes, thereby enhancing process quality.

Description

Technical Field

[0001] This disclosure relates to the field of welding technology, and in particular to a multi-electrode welding arc power supply for implementing various welding processes. Background Technology

[0002] Multi-electrode arc welding technology was initially developed to meet the demands of rapid production. In the manufacture of large structures such as ships and bridges, single-electrode welding could not meet the efficiency requirements. Multi-electrode arc welding uses two or more electrodes and the workpiece to simultaneously initiate an arc, which can largely overcome the limitations of single-electrode arc welding in terms of heat input, filler material, and weld pool stress. The advent of multi-electrode arc welding, by using multiple electrodes to weld simultaneously on the same workpiece, has significantly improved production efficiency.

[0003] Current research on multi-electrode arc welding technology mainly focuses on welding methods. Most of these methods use multiple independent welding power sources to supply power to multiple electrodes separately. This can easily lead to inconsistencies in the magnitude and polarity of the current output by each electrode with those of the other electrodes, resulting in decreased stability and reduced process quality of the multi-electrode arc welding system. Summary of the Invention

[0004] The purpose of this disclosure is to provide a multi-electrode arc welding power supply for implementing various welding processes, thereby solving the problem of decreased system stability caused by the inability to achieve unified driving of multi-electrode arc welding and the independent power supply of each electrode in the prior art.

[0005] The embodiments of this disclosure adopt the following technical solution: a multi-electrode welding arc power supply for realizing various welding processes, comprising at least: a DC constant voltage source, a first full-bridge module, a second full-bridge module, four inductors, eight output terminals, a drive circuit module, and a control circuit module; wherein, the positive terminal of the DC constant voltage source is connected to the first output terminal and the second output terminal respectively, and the negative terminal of the DC constant voltage source is connected to the third output terminal and the fourth output terminal respectively; the first full-bridge module includes at least a first bridge arm group and a second bridge arm group connected in parallel between the first output terminal and the third output terminal; the second full-bridge module includes at least a third bridge arm group and a fourth bridge arm group connected in parallel between the second output terminal and the fourth output terminal; the four inductors are respectively the first inductor, the second inductor, the third inductor, the fourth inductor, the fifth inductor, the sixth inductor, the seventh inductor, the eighth ... The system comprises a first inductor, a third inductor, and a fourth inductor. One end of the first inductor is connected to the midpoint of the first bridge arm group, and the other end of the first inductor is connected to the fifth output terminal. One end of the second inductor is connected to the midpoint of the second bridge arm group, and the other end of the second inductor is connected to the sixth output terminal. One end of the third inductor is connected to the midpoint of the third bridge arm group, and the other end of the third inductor is connected to the seventh output terminal. One end of the fourth inductor is connected to the midpoint of the fourth bridge arm group, and the other end of the fourth inductor is connected to the eighth output terminal. The control circuit module is connected to the drive terminals of all bridge arm groups through the drive circuit module. The drive circuit module controls the on / off state of each bridge arm in the bridge arm group according to the control signal of the control circuit module.

[0006] In some embodiments, the first bridge arm group includes at least a first bridge arm and a second bridge arm, with the current output terminal of the first bridge arm connected to the current input terminal of the second bridge arm; the second bridge arm group includes at least a third bridge arm and a fourth bridge arm, with the current output terminal of the third bridge arm connected to the current input terminal of the fourth bridge arm; the third bridge arm group includes at least a fifth bridge arm and a sixth bridge arm, with the current output terminal of the fifth bridge arm connected to the current input terminal of the sixth bridge arm; the fourth bridge arm group includes at least a seventh bridge arm and an eighth bridge arm, with the current output terminal of the seventh bridge arm connected to the current input terminal of the eighth bridge arm; each bridge arm includes at least a semiconductor switching device.

[0007] In some embodiments, the semiconductor switching device is an IGBT or a MOSFET.

[0008] In some embodiments, when the multi-electrode welding arc power supply is configured as a DC output, when the load is established between the two output terminals connected to the even-numbered bridge arm in the current bridge arm group, the on / off state of the odd-numbered bridge arm in the current bridge arm group is switched at a first preset frequency; when the load is established between the two output terminals connected to the odd-numbered bridge arm in the current bridge arm group, the on / off state of the even-numbered bridge arm in the current bridge arm group is switched at a first preset frequency.

[0009] In some embodiments, when the multi-electrode welding arc power supply is configured for pulse output, when the load is established between the two output terminals connected to the odd-numbered bridge arm in the current bridge arm group, the on / off state of the even-numbered bridge arm in the current bridge arm group is switched at a first preset frequency during the first pulse phase; during the second pulse phase, the even-numbered bridge arm is turned off; the first pulse phase and the second pulse phase are executed alternately to achieve pulse output.

[0010] In some embodiments, when the multi-electrode welding arc power supply is configured for AC output, when a load is established between the fifth and sixth output terminals, in the first stage, the on / off state of the first bridge arm is switched at a second preset frequency while the fourth bridge arm remains on; in the second stage, the first bridge arm is turned off while the fourth bridge arm remains on; in the third stage, the fourth bridge arm is turned off while the second bridge arm remains on, and the on / off state of the third bridge arm is switched at a second preset frequency; in the fourth stage, the second bridge arm remains on while the third bridge arm is turned off; the first to fourth stages are executed alternately to achieve AC output between the fifth and sixth output terminals.

[0011] In some embodiments, when the multi-electrode welding arc power supply is configured with one AC output and one DC output, and one end of the load is connected to the fifth and seventh output terminals, and the other end of the load is connected to the sixth and fourth output terminals, in the first stage, the on / off state of the first bridge arm is switched at a second preset frequency while the fourth bridge arm remains on; in the second stage, the first bridge arm is turned off while the fourth bridge arm remains on; in the third stage, the fourth bridge arm is turned off while the second bridge arm remains on, and the on / off state of the third bridge arm is switched at a second preset frequency; in the fourth stage, the second bridge arm remains on while the third bridge arm is turned off; the first to fourth stages are executed alternately to achieve AC output between the fifth and sixth output terminals; the on / off state of the fifth bridge arm is switched at a first preset frequency while the other bridge arms in the second full-bridge module, excluding the fifth bridge arm, are turned off to achieve DC output between the seventh and fourth output terminals.

[0012] In some embodiments, the DC constant voltage source includes at least: a rectifier module, a full-bridge inverter module, a high-frequency transformer, and a rectifier filter module connected in sequence, wherein the rectifier module inputs AC power and the rectifier filter module outputs constant voltage DC power.

[0013] In some embodiments, the system further includes: a first capacitor and a second capacitor, wherein the first capacitor is connected in parallel between the first output terminal and the third output terminal, and the second capacitor is connected in parallel between the second output terminal and the fourth output terminal.

[0014] In some embodiments, the system further includes: an output current sampling circuit module, an overcurrent and overheat protection circuit module, and a power calculation module; the output current sampling circuit module is connected to the control circuit module through the power calculation module, and the power calculation module calculates the power output of each output terminal based on the current signal of the output current sampling circuit module, so that the control circuit module adjusts the control signal according to the power output; the overcurrent and overheat protection circuit module is used to detect the output current of each output terminal and the operating temperature of each bridge arm, and in the event of overcurrent or overheating, the overcurrent and overheat protection circuit module interrupts the output of the drive circuit module.

[0015] The beneficial effects of this embodiment are as follows: by independently setting the eight electrode output terminals, it is possible to simultaneously output four controllable constant DC currents, four controllable pulse currents, or two controllable AC currents, thereby realizing the combination of various welding processes, effectively improving the coordination and stability of the outputs between the electrodes, and achieving the goal of improving process quality. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in one or more embodiments of this specification or in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this specification. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the structure of a multi-electrode welding arc power supply used to implement various welding processes in an embodiment of this disclosure;

[0018] Figure 2 This is a schematic diagram of the structure of the constant pressure source in the embodiments of this disclosure;

[0019] Figure 3 This is a schematic diagram of bridge arm conduction when the multi-electrode welding arc power supply implements the Tandem process in an embodiment of this disclosure;

[0020] Figure 4 This is a timing control diagram of the multi-electrode welding arc power supply implementing the Tandem process in the embodiments of this disclosure;

[0021] Figure 5 This is a schematic diagram of bridge arm conduction when the multi-electrode welding arc power supply implements the VPPA process in an embodiment of this disclosure;

[0022] Figure 6 As described in this embodiment of the disclosure Figure 6 This is a timing control diagram for implementing the VPPA process using a multi-electrode welding arc power supply in this embodiment;

[0023] Figure 7 This is a schematic diagram of the bridge arm conduction when the multi-electrode welding arc power supply realizes the cross-coupled arc process in the embodiments of this disclosure;

[0024] Figure 8 This is a timing control diagram for the cross-coupled arc process implemented by the multi-electrode welding arc power supply in the embodiments of this disclosure. Detailed Implementation

[0025] To enable those skilled in the art to better understand the technical solutions in one or more embodiments of this specification, the technical solutions in one or more embodiments of this specification will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this specification, and not all of the embodiments. Based on one or more embodiments of this specification, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of this document.

[0026] Multi-electrode arc welding technology was initially developed to meet the demands of rapid production. In the manufacturing of large structures such as ships and bridges, single-electrode welding could not meet the efficiency requirements. Multi-electrode arc welding uses two or more electrodes and the workpiece to simultaneously initiate an arc, largely overcoming the limitations of single-electrode arc welding in terms of heat input, filler material, and weld pool stress. The advent of multi-electrode arc welding significantly improved production efficiency by using multiple electrodes to weld simultaneously on the same workpiece. Multi-electrode welding has a wide range of applications, including aerospace, automotive, shipbuilding, nuclear energy, and construction industries. It can join metals or non-metals of different shapes, sizes, and materials, such as steel, aluminum alloys, nickel-based alloys, titanium alloys, and carbon fiber composites. It can also join dissimilar materials, such as steel-aluminum transition joints and steel-carbon fiber composite transition joints. With advancements in automation and control technologies, multi-electrode arc welding has evolved from simple parallel welding to more precise synchronous control. Modern multi-electrode welding systems integrate advanced sensors and control algorithms, achieving high-precision collaborative control and real-time monitoring.

[0027] Current research on multi-electrode arc welding technology mainly focuses on welding methods. Most of these methods use multiple independent welding power sources to supply power to multiple electrodes separately. This can easily lead to inconsistencies in the magnitude and polarity of the current output by each electrode with those of the other electrodes, resulting in decreased stability and reduced process quality of the multi-electrode arc welding system.

[0028] To address the aforementioned problems, this disclosure provides a multi-electrode welding arc power supply for implementing various welding processes, as shown in the schematic diagram below. Figure 1As shown, it includes at least: a DC constant voltage source 10, a first full-bridge module 20, a second full-bridge module 30, four inductors (L1 to L4), eight output terminals (OUT1 to OUT8), a drive circuit module 40, and a control circuit module 50.

[0029] The DC constant voltage source 10 has two output terminals, a positive terminal V+ and a negative terminal V-. The positive terminal V+ is connected to the first output terminal OUT1 and the second output terminal OUT2, while the negative terminal V- is connected to the third output terminal OUT3 and the fourth output terminal OUT4. In some embodiments, such as... Figure 2 As shown, the DC constant voltage source 10 includes at least a rectifier module 11, a full-bridge inverter module 12, a high-frequency transformer 23, and a rectifier filter module 14 connected in sequence. The rectifier module 11 is input with AC power (e.g., 380V / 50Hz), and the rectifier filter module 14 is output with constant voltage DC power.

[0030] The first full-bridge module 20 includes at least a first bridge arm group 21 and a second bridge arm group 22, which are connected in parallel between the first output terminal OUT1 and the third output terminal OUT3. Correspondingly, the second full-bridge module 30 includes at least a third bridge arm group 31 and a fourth bridge arm group 32, which are connected in parallel between the second output terminal OUT2 and the fourth output terminal OUT4. In this embodiment, each bridge arm group is formed by two bridge arms connected in series, such as... Figure 1 As shown, the first bridge arm group 21 consists of a first bridge arm Q1 and a second bridge arm Q2 connected in series, with the current output terminal of the first bridge arm Q1 connected to the current input terminal of the second bridge arm Q2; similarly, the second bridge arm group 22 includes at least a third bridge arm Q3 and a fourth bridge arm Q4, with the current output terminal of the third bridge arm Q3 connected to the current input terminal of the fourth bridge arm Q4; the third bridge arm group 31 includes at least a fifth bridge arm Q5 and a sixth bridge arm Q6, with the current output terminal of the fifth bridge arm Q5 connected to the current input terminal of the sixth bridge arm Q6; the fourth bridge arm group 32 includes at least a seventh bridge arm Q7 and an eighth bridge arm Q8, with the current output terminal of the seventh bridge arm Q7 connected to the current input terminal of the eighth bridge arm Q8. In this embodiment, each bridge arm includes at least a semiconductor switching device, such as an IGBT (Insulated Gate Bipolar Transistor) or a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) as the bridge arm. Simultaneously, a filter circuit is connected in parallel across the semiconductor switching device, the filter circuit including a series-connected filter resistor and a filter capacitor.

[0031] In this embodiment, the inductors are a first inductor L1, a second inductor L2, a third inductor L3, and a fourth inductor L4. One end of the first inductor L1 is connected to the midpoint of the first bridge arm group 21, that is, one end of the first inductor L1 is connected between the first bridge arm Q1 and the second bridge arm Q2, and the other end of the first inductor L1 is used as the fifth output terminal OUT5. Similarly, one end of the second inductor L2 is connected to the midpoint of the second bridge arm group 22, and the other end of the second inductor L2 is connected to the sixth output terminal OUT6. One end of the third inductor L3 is connected to the midpoint of the third bridge arm group 31, and the other end of the third inductor L3 is connected to the seventh output terminal OUT7. One end of the fourth inductor L4 is connected to the midpoint of the fourth bridge arm group 32, and the other end of the fourth inductor L4 is connected to the eighth output terminal OUT8.

[0032] In this embodiment, the control circuit module 50 is connected to the drive terminals of the bridge arm groups in each full-bridge module via the drive circuit module 40, i.e., connected to the control terminals of the semiconductor switching devices, to drive the switching of the on / off states of each bridge arm in the bridge arm group, and to achieve output control of different currents such as DC and AC through the on / off state control of the bridge arms. It should be noted that, since two full-bridge modules are set up in this embodiment, the corresponding drive circuit module 40 can also include a first drive circuit module 41 and a second drive circuit module 42, respectively controlling the first full-bridge module 20 and the second full-bridge module 30.

[0033] The control circuit module 50 generates a PWM control signal based on the actual welding requirements and outputs it to the drive circuit module 40. Its specific circuit structure may include a control chip, an analog-to-digital converter, and a PWM modulation circuit. It may also include a human-machine interaction module so that the operator can set the output current type according to the current welding requirements.

[0034] based on Figure 1As shown in the structure, when the multi-electrode welding arc power supply in this embodiment is configured as a DC output, when the load is established between the two output terminals connected to the even-numbered bridge arm in the current bridge arm group, the on / off state of the odd-numbered bridge arm in the current bridge arm group is switched at a first preset frequency; when the load is established between the two output terminals connected to the odd-numbered bridge arm in the current bridge arm group, the on / off state of the even-numbered bridge arm in the current bridge arm group is switched at a first preset frequency. When the load is connected between the fifth output terminal OUT5 and the third output terminal OUT3, it is equivalent to the load being connected between the two output terminals connected to the second bridge arm Q2 in the first bridge arm group. At this time, the first bridge arm Q1 is switched on and off at a high speed at a first preset frequency. When Q1 is on, the current flows from V+ through Q1 and L1, generating an induced electromotive force across L1, with the left end being positive and the right end being negative, thus slowing down the rise of the current and storing electrical energy. When Q1 is off, due to the freewheeling effect of L1, the current flows through L1 to OUT5, and from OUT3 to the body diode of Q2. Repeating the above steps can achieve DC current output, and at this time, a positive current is output between OUT5 and OUT3. Similarly, when the load is connected between the fifth output terminal OUT5 and the first output terminal OUT1, it is equivalent to the load being connected between the two output terminals connected to the first bridge arm Q1 in the first bridge arm group. The second bridge arm Q2 is switched on and off at a high speed at a first preset frequency to achieve DC current output between OUT5 and OUT1, and at this time, a negative current is output between OUT5 and OUT1.

[0035] Based on the principle of achieving DC output using a multi-electrode welding arc power supply, this embodiment can simultaneously achieve two to four constant DC outputs. Taking the Tandem process as an example, welding torches can be connected to OUT5 and OUT6, and the workpiece can be connected to OUT3 for welding. Arcs are initiated between OUT5 and OUT3, and between OUT6 and OUT3, respectively. Figure 3 The diagram illustrates the bridge arm conduction schematic of the multi-electrode welding arc power supply in this embodiment for the Tandem process. The thickened semiconductor switching devices and circuits are the devices that need to be switched on during the process implementation. Figure 4 This is a timing control diagram for the multi-electrode welding arc power supply in this embodiment to implement the Tandem process. R1 and I R2 The current between OUT5 and OUT3, and between OUT6 and OUT3, are shown below. Figure 4 As shown, I can be adjusted by changing the first preset frequency. R1 and I R2 The output is approximately constant DC.

[0036] In some embodiments, when the multi-electrode welding arc power supply is configured for pulse output, when the load is established between the two output terminals connected to the odd-numbered bridge arms in the current bridge arm group, during the first pulse phase, similar to the DC output case, the on / off state of the even-numbered bridge arms in the current bridge arm group is switched at a first preset frequency, and the power supply achieves DC output; during the second pulse phase, the even-numbered bridge arms are turned off, making the current output 0; by alternately executing the first pulse phase and the second pulse phase, pulse output can be achieved. Similarly, when the load is established between the two output terminals connected to the even-numbered bridge arms in the current bridge arm group, during the first pulse phase, the on / off state of the odd-numbered bridge arms in the current bridge arm group is switched at a first preset frequency; during the second pulse phase, the odd-numbered bridge arms are turned off. It should be noted that the specific duration of the first pulse phase and the second pulse phase can be adaptively adjusted according to the characteristics of the semiconductor switching device and the magnitude of the current when pulsed DC output occurs; this embodiment will not provide a specific description here.

[0037] When the multi-electrode welding arc power supply of this embodiment is configured for AC output, the output terminal led out from the midpoint of each bridge arm group in each full-bridge module is used as the output electrode and connected to the load. Taking the load established between the fifth output terminal OUT5 and the sixth output terminal OUT6 as an example, the AC output power includes four stages. Specifically, in the first stage, the on / off state of the first bridge arm Q1 is switched at a second preset frequency, while the fourth bridge arm 14 remains on; in the second stage, the first bridge arm Q1 is turned off, while the fourth bridge arm Q4 remains on; in the third stage, the fourth bridge arm Q4 is turned off, the second bridge arm Q2 remains on, and the on / off state of the third bridge arm Q3 is switched at a second preset frequency; in the fourth stage, the second bridge arm Q2 remains on, while the third bridge arm Q3 is turned off; the first to fourth stages are executed alternately to achieve AC output between the fifth output terminal OUT5 and the sixth output terminal OUT6. If the load is established between the seventh output terminal OUT7 and the eighth output terminal OUT8, the principle of outputting AC power between them is the same as when the load is established between the fifth output terminal OUT5 and the sixth output terminal OUT6, and will not be repeated here.

[0038] Specifically, in this embodiment, during AC output, one bridge arm in both the first and third stages remains on and off at high frequency, while the other bridge arm remains normally open, thereby controlling the magnitude of the output AC current; while the second and fourth stages are for the purpose of freewheeling in the circuit, thereby reducing current stress.

[0039] Based on the principle of AC output from a multi-electrode welding arc power supply, the multi-electrode welding arc power supply in this embodiment can simultaneously achieve two AC outputs. Taking the bypass-coupled VPPA welding process as an example, firstly, an AC main arc is established between OUT7 and OUT8. In the first stage, Q5 is switched on and off at high frequency, while Q8 remains on, and the current flows from OUT7 to OUT8. In the second stage, Q5 is switched off, while Q8 remains on. Due to the freewheeling effect of L3 and L4, the current flows from Q8 to the body diode of Q6, and then through OUT7 to OUT8. In the third stage, Q8 is switched off, Q6 remains on, and Q7 is switched on and off at high frequency, and the current flows from OUT8 to OUT7. In the fourth stage, Q6 remains on, while Q7 is switched off. Due to the freewheeling effect of L3 and L4, the current flows from Q6 to the body diode of Q8, and then through OUT8 to OUT7. Secondly, an AC bypass arc is established between OUT5 and OUT6: In the first stage, Q2 is turned on and off at high frequency, while Q4 remains on. At this time, the current flows from OUT5 to OUT6. In the second stage, Q2 is turned off, while Q4 remains on. Due to the freewheeling effect of L1 and L2, the current flows from Q4 to the body diode of Q2, and then through OUT5 to OUT6. In the third stage, Q4 is turned off, Q2 remains on, and Q3 is turned on and off at high frequency. At this time, the current flows from OUT6 to OUT5. In the fourth stage, Q2 remains on, while Q3 is turned off. Due to the freewheeling effect of L1 and L2, the current flows from Q2 to the body diode of Q4, and then through OUT6 to OUT5.

[0040] Figure 5 This diagram illustrates the bridge arm conduction when the multi-electrode welding arc power supply of this embodiment implements the VPPA process.

[0041] Figure 6 This is a timing control diagram for implementing the VPPA process using a multi-electrode welding arc power supply in this embodiment.

[0042] In some embodiments, the multi-electrode welding arc power supply of this embodiment can also simultaneously output one DC output and one AC output. Taking the cross-coupled arc welding process as an example, an AC arc is established between OUT5 and OUT6: In the first stage, Q1 is switched on and off at high frequency, while Q4 remains on, and the current flows from OUT5 to OUT6; in the second stage, Q1 is switched off, while Q4 remains on, and due to the freewheeling effect of L1 and L2, the current flows from Q4 to the body diode of Q2, and then through OUT5 to OUT6; in the third stage, Q4 is switched off, Q2 remains on, and Q3 is switched on and off at high frequency, and the current flows from OUT6 to OUT5; in the fourth stage, Q2 remains on, while Q3 is switched off, and due to the freewheeling effect of L1 and L2, the current flows from Q2 to the body diode of Q4, and then through OUT6 to OUT5. The main arc is a DC arc between OUT7 and OUT4, formed by chopping control through the high-frequency switching on and off of Q5. When Q5 is turned on, the current flows from the OUT7 terminal through the inductor L3, and an induced electromotive force is generated across the inductor L3, with the left end being positive and the right end being negative, which slows down the rise of the current and stores electrical energy. When Q5 is turned off, due to the freewheeling effect of the inductor L3, the current flows through L3 to OUT7, and from OUT4 to the body diode of Q6, thereby realizing DC output. Figure 7 This diagram illustrates the bridge arm conduction when the multi-electrode welding arc power supply of this embodiment implements the cross-coupled arc process. Figure 8 This is a timing control diagram for the cross-coupled arc process implemented by the multi-electrode welding arc power supply in this embodiment.

[0043] In some embodiments, the power supply also includes a first capacitor C1 and a second capacitor C2 for storing energy from the inductor during the bridge arm dead time. This energy can be released when the arc is re-established with opposite polarity, thereby providing additional boost or overshoot in addition to the current supplied by the constant current source and the inductor. Specifically, the first capacitor is connected in parallel between the first output terminal OUT1 and the third output terminal OUT3, and the second capacitor C2 is connected in parallel between the second output terminal OUT2 and the fourth output terminal OUT4.

[0044] In some embodiments, the power supply further includes an output current sampling circuit module 60, an overcurrent and overheat protection circuit module, and a power calculation module (not shown in the figure). The output current sampling circuit module 60 includes a first output current sampling circuit 61 and a second output current sampling circuit 62, both connected to the control circuit module via the power calculation module. The power calculation module calculates the power output of each output terminal based on the current signal from the output current sampling circuit module, enabling the control circuit module to adjust the control signal according to the power output. The overcurrent and overheat protection circuit module detects the output current of each output terminal and the operating temperature of each bridge arm. In the event of overcurrent or overheating, the overcurrent and overheat protection circuit module interrupts the output of the drive circuit module.

[0045] This embodiment, through the independent setting of eight electrode output terminals, can achieve a maximum simultaneous output of four controllable constant DC currents, four controllable pulse currents, or a maximum simultaneous output of two controllable AC currents, realizing a combination of various welding processes, effectively improving the coordination and stability of the outputs between each electrode, and achieving the goal of improving process quality.

[0046] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this disclosure, and are not intended to limit them. Although this disclosure has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this disclosure.

Claims

1. A multi-electrode welding arc power source for realizing various welding processes, characterized in that, At least including: The system includes a DC constant voltage source, a first full-bridge module, a second full-bridge module, four inductors, eight output terminals, a drive circuit module, and a control circuit module; among which, The positive terminal of the DC constant voltage source is connected to the first output terminal and the second output terminal, respectively, and the negative terminal of the DC constant voltage source is connected to the third output terminal and the fourth output terminal, respectively. The first full-bridge module includes at least a first bridge arm group and a second bridge arm group connected in parallel between the first output terminal and the third output terminal; the second full-bridge module includes at least a third bridge arm group and a fourth bridge arm group connected in parallel between the second output terminal and the fourth output terminal. The four inductors are designated as a first inductor, a second inductor, a third inductor, and a fourth inductor. One end of the first inductor is connected to the midpoint of the first bridge arm group, and the other end of the first inductor is connected to the fifth output terminal. One end of the second inductor is connected to the midpoint of the second bridge arm group, and the other end of the second inductor is connected to the sixth output terminal. One end of the third inductor is connected to the midpoint of the third bridge arm group, and the other end of the third inductor is connected to the seventh output terminal. One end of the fourth inductor is connected to the midpoint of the fourth bridge arm group, and the other end of the fourth inductor is connected to the eighth output terminal. The control circuit module is connected to the drive end of each bridge arm group through the drive circuit module. The drive circuit module controls the on / off state of each bridge arm in the bridge arm group according to the control signal of the control circuit module.

2. The multi-electrode welding arc power supply according to claim 1, characterized in that, The first bridge arm group includes at least a first bridge arm and a second bridge arm, wherein the current output terminal of the first bridge arm is connected to the current input terminal of the second bridge arm; The second bridge arm group includes at least a third bridge arm and a fourth bridge arm, wherein the current output terminal of the third bridge arm is connected to the current input terminal of the fourth bridge arm; The third bridge arm group includes at least a fifth bridge arm and a sixth bridge arm, wherein the current output terminal of the fifth bridge arm is connected to the current input terminal of the sixth bridge arm. The fourth bridge arm group includes at least a seventh bridge arm and an eighth bridge arm, wherein the current output terminal of the seventh bridge arm is connected to the current input terminal of the eighth bridge arm; Each bridge arm includes at least one semiconductor switching device.

3. The multi-electrode welding arc power supply according to claim 2, characterized in that, The semiconductor switching device is an IGBT or a MOSFET.

4. The multi-electrode welding arc power supply according to claim 2, characterized in that, When the multi-electrode welding arc power supply is configured as a DC output, when the load is established between the two output terminals connected to the even-numbered bridge arm in the current bridge arm group, the on / off state of the odd-numbered bridge arm in the current bridge arm group is switched at a first preset frequency. When a load is established between two output terminals connected to an odd-numbered bridge arm in the current bridge arm group, the on / off state of the even-numbered bridge arms in the current bridge arm group is switched at a first preset frequency.

5. The multi-electrode welding arc power supply according to claim 2, characterized in that, When the multi-electrode welding arc power supply is configured for pulse output... When the load is established between the two output terminals connected to the odd-numbered bridge arm in the current bridge arm group, the on / off state of the even-numbered bridge arm in the current bridge arm group is switched at a first preset frequency during the first pulse phase. During the second pulse phase, the even-numbered bridge arms are turned off; the first pulse phase and the second pulse phase are executed alternately to achieve pulse output.

6. The multi-electrode welding arc power supply according to claim 2, characterized in that, When the multi-electrode welding arc power supply is configured as an AC output, when the load is established between the fifth and sixth output terminals, in the first stage, the on / off state of the first bridge arm is switched at a second preset frequency while the fourth bridge arm remains on; in the second stage, the first bridge arm is turned off while the fourth bridge arm remains on; in the third stage, the fourth bridge arm is turned off while the second bridge arm remains on, and the on / off state of the third bridge arm is switched at a second preset frequency. In the fourth stage, the second bridge arm remains open while the third bridge arm is turned off; the first to fourth stages are executed alternately to achieve AC output between the fifth and sixth output terminals.

7. The multi-electrode welding arc power supply according to claim 2, characterized in that, When the multi-electrode welding arc power supply is configured with one AC output and one DC output, and one end of the load is connected to the fifth and seventh output terminals, and the other end of the load is connected to the sixth and fourth output terminals... In the first stage, the on / off state of the first bridge arm is switched at a second preset frequency, while the fourth bridge arm remains on; in the second stage, the first bridge arm is turned off, while the fourth bridge arm remains on; in the third stage, the fourth bridge arm is turned off, the second bridge arm remains on, and the on / off state of the third bridge arm is switched at a second preset frequency. In the fourth stage, the second bridge arm remains open while the third bridge arm is turned off; the first to fourth stages are executed alternately to achieve AC output between the fifth and sixth output terminals. The on / off state of the fifth bridge arm is switched at a first preset frequency, and the other bridge arms in the second full-bridge module except for the fifth bridge arm are turned off, so as to enable DC output between the seventh output terminal and the fourth output terminal.

8. The multi-electrode welding arc power supply according to claim 1, characterized in that, The DC constant voltage source includes at least: a rectifier module, a full-bridge inverter module, a high-frequency transformer, and a rectifier filter module connected in sequence, wherein the rectifier module inputs AC power and the rectifier filter module outputs constant voltage DC power.

9. The multi-electrode welding arc power supply according to claim 1, characterized in that, Also includes: A first capacitor and a second capacitor, wherein the first capacitor is connected in parallel between the first output terminal and the third output terminal, and the second capacitor is connected in parallel between the second output terminal and the fourth output terminal.

10. The multi-electrode welding arc power supply according to any one of claims 1 to 9, characterized in that, Also includes: Output current sampling circuit module, overcurrent and overheat protection circuit module, and power calculation module; The output current sampling circuit module is connected to the control circuit module through the power calculation module. The power calculation module calculates the power output of each output terminal based on the current signal of the output current sampling circuit module, so that the control circuit module adjusts the control signal according to the power output. The overcurrent and overheat protection circuit module is used to detect the output current of each output terminal and the operating temperature of each bridge arm. In the event of overcurrent or overheating, the overcurrent and overheat protection circuit module interrupts the output of the drive circuit module.

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