An alternating current arc zero-crossing arc control system and method

Abstract

The application discloses an alternating current arc zero-crossing arc control system and method, which comprises the following steps: a power supply module receives alternating current from a welding machine main transformer; a rectifier module converts the alternating current into direct current; the electric energy of the direct current is stored in an energy storage module; a control module inputs a switching value signal into a driving module when the alternating current arc crosses zero and is positively rotated negative or negatively rotated positive; the driving module converts the switching value signal into a driving signal and controls an execution module to be turned on for a fixed time and then turned off; a voltage pulse is formed on the welding machine main circuit by using the electric energy of the direct current stored in the energy storage module, so that the welding gun end is higher than the base material end or the base material end is higher than the welding gun end; and the voltage pulse assists the alternating current arc to be positively rotated negative or negatively rotated positive. The application solves the problem that the arc is easily broken when the alternating current arc output current crosses zero.

Description

Technical Field

[0001] This invention relates to the field of welding technology, and in particular to an AC arc zero-dimensional arc control system and method. Background Technology

[0002] Aluminum and aluminum alloys play a crucial role in modern engineering technology, and AC arc welding power supplies are widely used in welding aluminum and aluminum alloys. Aluminum and aluminum alloys typically have a dense oxide layer on their surface, with a melting point generally above 2000℃. Welding of aluminum and aluminum alloys requires removing this oxide layer. During AC welding, the tungsten electrode continuously switches between positive and negative electrodes. When the tungsten electrode is positive, electrons move from the workpiece to the tungsten electrode, removing the oxide layer. Then, when the tungsten electrode is negative, electrons move from the tungsten electrode to the workpiece surface, generating heat to complete the welding. Due to the frequent changes in AC current, the oxide film has no opportunity to regenerate, effectively controlling the stability of the weld quality. A key challenge in AC arc control is that the arc is extinguished at the moment it crosses zero. The process of the AC arc crossing zero is essentially the process of the arc extinguishing and then reigniting. Improper control methods can easily cause arc interruption at the zero-crossing point, adversely affecting the workpiece being welded.

[0003] Currently, the main solutions to this problem in the welding market are zero-crossing high-frequency re-arc restart and auxiliary contact re-arc restart. Since AC welding frequencies are generally between tens and hundreds of hertz, high-frequency re-arc restart at each zero crossing can indeed ensure a smooth zero crossing. However, the high-frequency signal will cause high-frequency interference to the welding machine and peripheral equipment, increasing the probability of damage to these devices. Contact arc ignition is mainly used in consumable electrode welding power supplies. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide an AC arc zero-crossing arc control system and method to solve the problem of arc interruption when the AC arc output current crosses zero.

[0005] To solve the above-mentioned technical problems, the present invention is implemented using the following solution: This invention provides an AC arc zero-crossing arc control system, comprising a power supply module, a rectifier module, an energy storage module, a control module, a drive module, an execution module, and a transformer module. The power supply module, rectifier module, energy storage module, execution module, and transformer module are connected sequentially, as are the control module, drive module, and execution module. The input terminal of the power supply module is connected to the output terminal of the welding machine's main transformer, and the transformer module is coupled into the welding machine's main circuit. The power supply module receives AC power from the welding machine's main transformer, the rectifier module converts the AC power into DC power, and the DC power energy is stored in the energy storage module. When the AC arc crosses zero and changes from positive to negative or from negative to positive, the control module inputs a switching signal to the drive module. The drive module converts the switching signal into a drive signal and controls the execution module to conduct for a fixed time before turning it off. The transformer module utilizes the DC power stored in the energy storage module to form a current with a specific direction, causing a voltage pulse in the welding machine's main circuit where the welding torch end is higher than the base material end or vice versa. This voltage pulse assists in the AC arc changing from positive to negative or vice versa.

[0006] Furthermore, the power supply module includes a fifth capacitor, the rectifier module includes a first diode, a second diode, a third diode, and a fourth diode, the energy storage module includes a first resistor and a first capacitor, the execution module includes the same first switch control chip, second switch control chip, third switch control chip, and fourth switch control chip, and the transformer module includes a transformer; one end of the output terminal of the power supply module is connected in series with the fifth capacitor and then connected to the anode of the first diode, the other end of the output terminal of the power supply module is connected to the anode of the second diode, the anode of the first diode is connected to the cathode of the third diode, the cathode of the first diode is connected to the cathode of the second diode, the anode of the second diode is connected to the cathode of the fourth diode, the anode of the fourth diode is connected to the anode of the third diode, the two ends of the first resistor are respectively connected to the anode of the fourth diode and one end of the first capacitor, the other end of the first capacitor is connected to the cathode of the second diode, the first switch control chip, the second switch control chip, the third switch control chip, and the fourth switch control chip form a full-bridge circuit, the two ends of the first capacitor are connected to the input terminal of the full-bridge circuit, and the transformer is connected to the output terminal of the full-bridge circuit.

[0007] Further, the first switch control chip includes a first switch transistor, a sixth diode, a sixth resistor, and a sixth capacitor. The cathode of the sixth diode is connected to the collector of the first switch transistor, and the anode of the sixth diode is connected to the emitter of the first switch transistor. One end of the sixth resistor is connected to the collector of the first switch transistor, and the other end of the sixth resistor is connected to one end of the sixth capacitor. The other end of the sixth capacitor is connected to the emitter of the first switch transistor. The second switch control chip includes a second switch transistor, a seventh diode, a seventh resistor, and a seventh capacitor. The cathode of the seventh diode is connected to the collector of the second switch transistor, and the anode of the seventh diode is connected to the emitter of the second switch transistor. One end of the seventh resistor is connected to the collector of the second switch transistor, and the other end of the seventh resistor is connected to one end of the seventh capacitor. The other end of the seventh capacitor is connected to the emitter of the second switch transistor. The third switch control chip includes a third switch transistor, an eighth diode, an eighth resistor, and an eighth capacitor. The cathode of the eighth diode is connected to the collector of the third switch transistor, and the anode of the eighth diode is connected to the emitter of the third switch transistor. One end of the eighth resistor is connected to the collector of the third switch transistor, and the other end of the eighth resistor is connected to the emitter of the first switch transistor. One end is connected to one end of the eighth capacitor, and the other end of the eighth capacitor is connected to the emitter of the third switching transistor; the fourth switch control chip includes a fourth switching transistor, a ninth diode, a ninth resistor, and a ninth capacitor. The negative terminal of the ninth diode is connected to the collector of the fourth switching transistor, and the positive terminal of the ninth diode is connected to the emitter of the fourth switching transistor. One end of the ninth resistor is connected to the collector of the fourth switching transistor, and the other end of the ninth resistor is connected to one end of the ninth capacitor. The other end of the ninth capacitor is connected to the emitter of the fourth switching transistor; the collectors of the first and third switching transistors are connected, and the emitters of the second and fourth switching transistors are connected. The emitter of the first switching transistor is connected to the collector of the second switching transistor, and the emitter of the third switching transistor is connected to the collector of the fourth switching transistor; the drive module is connected to the first, second, third, and fourth switching transistors respectively; the two ends of the first capacitor are connected to the collector of the first switching transistor and the emitter of the second switching transistor respectively; the transformer is connected to the connection circuit between the emitter of the first switching transistor and the collector of the second switching transistor, and the connection circuit between the emitter of the third switching transistor and the collector of the fourth switching transistor.

[0008] Furthermore, the power supply module includes a fifth capacitor, the rectifier module includes a first diode, a second diode, a third diode, and a fourth diode, the energy storage module includes a first resistor, a first capacitor, a second resistor, and a second capacitor, the execution module includes the same first switch control chip and second switch control chip, and the transformer module includes a transformer; one end of the output terminal of the power supply module is connected in series with the fifth capacitor and then connected to the positive terminal of the first diode, the other end of the output terminal of the power supply module is connected to the positive terminal of the second diode, the positive terminal of the first diode is connected to the negative terminal of the third diode, the negative terminal of the first diode is connected to the negative terminal of the second diode, the positive terminal of the second diode is connected to the negative terminal of the fourth diode, the positive terminal of the fourth diode is connected to the positive terminal of the third diode, the two ends of the first resistor are respectively connected to the negative terminal of the second diode and one end of the first capacitor, the two ends of the second resistor are respectively connected to the positive terminal of the fourth diode and one end of the second capacitor, the other ends of the first capacitor and the second capacitor are connected together, the first switch control chip and the second switch control chip form a half-bridge circuit, one end of the first capacitor and the second capacitor are connected to the input terminal of the half-bridge circuit, one end of the transformer is connected to the output terminal of the half-bridge circuit, and the other end is connected to the center tap of the main transformer of the welding machine.

[0009] Furthermore, the first switch control chip includes a first switching transistor, a sixth diode, a sixth resistor, and a sixth capacitor. The cathode of the sixth diode is connected to the collector of the first switching transistor, and the anode of the sixth diode is connected to the emitter of the first switching transistor. One end of the sixth resistor is connected to the collector of the first switching transistor, and the other end of the sixth resistor is connected to one end of the sixth capacitor. The other end of the sixth capacitor is connected to the emitter of the first switching transistor. The second switch control chip includes a second switching transistor, a seventh diode, a seventh resistor, and a seventh capacitor. The cathode of the seventh diode is connected to the collector of the second switching transistor, and the anode of the seventh diode is connected to the emitter of the second switching transistor. The emitter of the first switching transistor is connected to the collector of the second switching transistor, one end of the seventh resistor is connected to the collector of the second switching transistor, the other end of the seventh resistor is connected to one end of the seventh capacitor, and the other end of the seventh capacitor is connected to the emitter of the second switching transistor; the emitter of the first switching transistor is connected to the collector of the second switching transistor; one end of the first capacitor is connected to the collector of the first switching transistor, and one end of the second capacitor is connected to the emitter of the second switching transistor; the drive module is connected to the first switching transistor and the second switching transistor respectively; one end of the transformer is connected to the connection circuit of the emitter of the first switching transistor and the collector of the second switching transistor, and the other end is connected to the connection circuit of the other ends of the first capacitor and the second capacitor.

[0010] Furthermore, the power supply module includes a fifth capacitor, the rectifier module includes a first diode, a second diode, a third diode, and a fourth diode, the energy storage module includes a first resistor and a first capacitor, the execution module includes a first switch control chip, and the transformer module includes a transformer. One end of the output terminal of the power supply module is connected in series with the fifth capacitor and then connected to the positive terminal of the first diode. The other end of the output terminal of the power supply module is connected to the positive terminal of the second diode. The positive terminal of the first diode is connected to the negative terminal of the third diode, the negative terminal of the first diode is connected to the negative terminal of the second diode, the positive terminal of the second diode is connected to the negative terminal of the fourth diode, and the positive terminal of the fourth diode is connected to the positive terminal of the third diode. The two ends of the first resistor are respectively connected to the negative terminal of the second diode and one end of the first capacitor. The other end of the first capacitor is connected to the positive terminal of the fourth diode. One end of the transformer is connected to the output terminal of the first switch control chip, and the two ends of the first capacitor are respectively connected to the input terminal of the first switch control chip and the other end of the transformer.

[0011] Furthermore, the first switch control chip includes a first switch transistor, a sixth diode, a sixth resistor, and a sixth capacitor. The negative terminal of the sixth diode is connected to the collector of the first switch transistor, and the positive terminal of the sixth diode is connected to the emitter of the first switch transistor. One end of the sixth resistor is connected to the collector of the first switch transistor, and the other end of the sixth resistor is connected to one end of the sixth capacitor. The other end of the sixth capacitor is connected to the emitter of the first switch transistor. The drive module is connected to the first switch transistor. One end of the transformer is connected to the emitter of the first switch transistor, and one end of the first capacitor is connected to the collector of the first switch transistor. The other end of the first capacitor is connected to the other end of the transformer.

[0012] The present invention also provides an AC arc zero-dimensional arc control method, applied to the aforementioned AC arc zero-dimensional arc control system, comprising: When the AC arc crosses zero and changes from positive to negative, if the output current value of the welding machine is detected to be less than the first preset value, a certain delay is made. If the output current value of the welding machine is detected to be less than the second preset value after the delay, the control module has no output. If the output current value of the welding machine is detected to be greater than the second preset value after the delay, the control module inputs a switch signal to the drive module. The drive module converts the switch signal into a drive signal and controls the execution module to turn on for a fixed time and then turn off. The transformer module uses the DC power stored in the energy storage module to form a current in a certain direction, so that a voltage pulse is formed on the main circuit of the welding machine with the welding gun end higher than the base material end. The voltage pulse assists the AC arc to change from positive to negative. When the AC arc crosses zero and turns from negative to positive, if the output current value of the welding machine is detected to be greater than the third preset value, a certain delay is made. If the output current value of the welding machine is detected to be greater than the fourth preset value after the delay, the control module has no output. If the output current value of the welding machine is detected to be less than the fourth preset value after the delay, the control module inputs a switch signal to the drive module. The drive module converts the switch signal into a drive signal and controls the execution module to turn on for a fixed time and then turn off. The transformer module uses the DC power stored in the energy storage module to form a current in a certain direction, so that a voltage pulse is formed on the main circuit of the welding machine with the base material end higher than the welding gun end. The voltage pulse assists the AC arc to turn from negative to positive. The DC power stored in the energy storage module is obtained by converting AC power received from the main transformer of the welding machine by the power supply module into DC power through the rectifier module and then storing it in the energy storage module.

[0013] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: The present invention receives AC power from the main transformer of the welding machine through the power supply module, the rectifier module converts the AC power into DC power, the DC power energy is stored in the energy storage module, the control module inputs a switch signal to the drive module when the AC arc crosses zero and turns from positive to negative or from negative to positive, the drive module converts the switch signal into a drive signal and controls the execution module to turn on for a fixed time and then turn off, the transformer module uses the DC power energy stored in the energy storage module to form a current with a certain direction, so that a voltage pulse is formed on the main circuit of the welding machine with the welding gun end higher than the base material end or the base material end higher than the welding gun end. The voltage pulse assists the AC arc to turn from positive to negative or from negative to positive, thus solving the problem of arc interruption when the AC arc output current crosses zero. Attached Figure Description

[0014] Figure 1 This is a control block diagram of an AC arc zero-dimensional arc control system provided in an embodiment of the present invention; Figure 2 This is a control principle diagram of an AC arc zero-dimensional arc control system provided in Embodiment 1 of the present invention; Figure 3 This is a control principle diagram of an AC arc zero-crossing arc control system provided in Embodiment 2 of the present invention; Figure 4 This is a control principle diagram of an AC arc zero-crossing arc control system provided in Embodiment 3 of the present invention; Figure 5 This is a flowchart of a method for controlling the positive-to-negative zero-dimensional arc of an AC arc according to Embodiment 1 of the present invention; Figure 6 This is a flowchart of a method for controlling the negative-to-positive zero-dimensional arc of an AC arc according to Embodiment 1 of the present invention; Figure 7 This is a flowchart of a method for controlling the positive-to-negative zero-dimensional arc of an AC arc according to Embodiment 2 of the present invention; Figure 8 This is a flowchart of a method for controlling the negative-to-positive zero-dimensional arc of an AC arc according to Embodiment 2 of the present invention; Figure 9 This is a flowchart of a method for controlling the positive-to-negative zero-dimensional arc of an AC arc, as provided in Embodiment 3 of the present invention. Figure 10 This is a flowchart of a method for controlling the negative-to-positive zero-dimensional arc of an AC arc, provided in Embodiment 3 of the present invention. Detailed Implementation

[0015] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention. Example 1:

[0016] Please see Figure 1 and Figure 2 This embodiment provides an AC arc zero-dimensional arc control system, including a power supply module, a rectifier module, an energy storage module, a control module, a drive module, an execution module, and a transformer module. The power supply module, rectifier module, energy storage module, execution module, and transformer module are connected in sequence, and the control module, drive module, and execution module are connected in sequence. The input terminal of the power supply module is connected to the output terminal of the welding machine's main transformer, and the transformer module is coupled into the welding machine's main circuit.

[0017] Specifically, the power supply module includes a fifth capacitor C5, the rectifier module includes a first diode D1, a second diode D2, a third diode D3, and a fourth diode D4, the energy storage module includes a first resistor R1 and a first capacitor C1, the execution module includes the same first, second, third, and fourth switch control chips, and the transformer module includes a transformer T2; one end of the power supply module's output terminal is connected in series with the fifth capacitor C5 and then connected to the positive terminal of the first diode D1, the other end of the power supply module's output terminal is connected to the positive terminal of the second diode D2, and the positive terminal of the first diode D1 is connected to the third diode D3. The negative terminal of the first diode D1 is connected to the negative terminal of the second diode D2, the positive terminal of the second diode D2 is connected to the negative terminal of the fourth diode D4, the positive terminal of the fourth diode D4 is connected to the positive terminal of the third diode D3, the two ends of the first resistor R1 are respectively connected to the positive terminal of the fourth diode D4 and one end of the first capacitor C1, and the other end of the first capacitor C1 is connected to the negative terminal of the second diode D2. The first switch control chip, the second switch control chip, the third switch control chip and the fourth switch control chip form a full bridge circuit. The two ends of the first capacitor C1 are connected to the input terminal of the full bridge circuit, and the transformer T2 is connected to the output terminal of the full bridge circuit.The first switch control chip includes a first switch transistor Q1, a sixth diode D6, a sixth resistor R6, and a sixth capacitor C6. The cathode of the sixth diode D6 is connected to the collector of the first switch transistor Q1, and the anode of the sixth diode D6 is connected to the emitter of the first switch transistor Q1. One end of the sixth resistor R6 is connected to the collector of the first switch transistor Q1, and the other end of the sixth resistor R6 is connected to one end of the sixth capacitor C6. The other end of the sixth capacitor C6 is connected to the emitter of the first switch transistor Q1. The second switch control chip includes a second switch transistor Q2, a seventh diode D7, a seventh resistor R7, and a seventh capacitor C7. The cathode of the seventh diode D7 is connected to the collector of the second switch transistor Q2. The seventh diode D7 is connected to the emitter of the second switch Q2. One end of the seventh resistor R7 is connected to the collector of the second switch Q2, and the other end of the seventh resistor R7 is connected to one end of the seventh capacitor C7. The other end of the seventh capacitor C7 is connected to the emitter of the second switch Q2. The third switch control chip includes a third switch Q3, an eighth diode D8, an eighth resistor R8, and an eighth capacitor C8. The cathode of the eighth diode D8 is connected to the collector of the third switch Q3, and the anode of the eighth diode D8 is connected to the emitter of the third switch Q3. One end of the eighth resistor R8 is connected to the collector of the third switch Q3, and the other end of the eighth resistor R8 is connected to the emitter of the second switch Q2. One end of the first switch is connected to one end of the eighth capacitor C8, and the other end of the eighth capacitor C8 is connected to the emitter of the third switch Q3. The fourth switch control chip includes a fourth switch Q4, a ninth diode D9, a ninth resistor R9, and a ninth capacitor C9. The cathode of the ninth diode D9 is connected to the collector of the fourth switch Q4, and the anode of the ninth diode D9 is connected to the emitter of the fourth switch Q4. One end of the ninth resistor R9 is connected to the collector of the fourth switch Q4, and the other end of the ninth resistor R9 is connected to one end of the ninth capacitor C9. The other end of the ninth capacitor C9 is connected to the emitter of the fourth switch Q4. The collectors of the first switch Q1 and the third switch Q3 are connected. The emitters of the second switch Q2 and the fourth switch Q4 are connected. The emitter of the first switch Q1 is connected to the collector of the second switch Q2, and the emitter of the third switch Q3 is connected to the collector of the fourth switch Q4. The drive module is connected to the first switch Q1, the second switch Q2, the third switch Q3, and the fourth switch Q4 respectively. The two ends of the first capacitor C1 are connected to the collector of the first switch Q1 and the emitter of the second switch Q2 respectively. The transformer T2 is connected to the connection circuit between the emitter of the first switch Q1 and the collector of the second switch Q2 and the connection circuit between the emitter of the third switch Q3 and the collector of the fourth switch Q4.

[0018] Working principle: The power supply module receives AC power directly from the welding machine's main transformer. The rectifier module converts the AC power into DC power. The DC power then charges the first capacitor C1 in the energy storage module through the first resistor R1 (the first capacitor C1 is continuously charged during the time the welding machine's AC arc output is not yet at zero, until it is fully charged). In other words, the DC power is stored in the energy storage module. When arc-maintaining energy output is needed, the H-bridge circuit in the execution module discharges the first capacitor C1 according to the direction of the AC arc crossing zero (positive to negative or negative to positive). The DC power is finally coupled into the welding machine's main circuit through the transformer T2 in the transformer module to complete the arc-maintaining control at zero arc crossing.

[0019] When the AC arc crosses zero, the control module handles two cases: positive to negative and negative to positive. When the arc crosses zero, the control module inputs a switching signal to the drive module. After the drive module converts the signal into a drive signal, it controls the first switch Q1 and the fourth switch Q4 in the control execution module to conduct for a fixed time and then turn them off in time. At this time, the transformer module relies on the DC power stored in the energy storage module. A current will flow from point A to point B in the transformer T2. At the same time, a voltage pulse will be generated on the main circuit of the welding machine, with the welding gun end being higher than the base material end. This voltage pulse is used to assist the AC arc to switch from positive to negative, completing the arc zero-crossing arc control. When the signal changes from negative to positive, the control module inputs the switching signal to the drive module. After being converted into a drive signal by the drive module, the second switch Q2 and the third switch Q3 in the control execution module are turned on for a fixed time and then turned off in time. At this time, the transformer module relies on the DC power stored in the energy storage module. A current will be generated in the transformer T2 from point B to point A. At the same time, a voltage pulse will be generated on the main circuit of the welding machine, with the base material end being higher than the welding gun end. This voltage pulse is used to assist the AC arc to change from negative to positive, completing the arc zero-dimensional arc control.

[0020] Please see Figure 5 and Figure 6 This embodiment also provides an AC arc zero-dimensional arc control method, applied to the AC arc zero-dimensional arc control system described in this embodiment, including: The control module contains software programs used to determine the direction and timing of zero-crossing arc control. Based on parameters such as the AC frequency and cleaning width preset by the welding machine, it completes the zero-crossing control of the welding machine's main circuit, that is, it completes the positive-to-negative or negative-to-positive output action at the correct time, and simultaneously begins monitoring the actual output current value of the welding machine.

[0021] The specific control process is as follows: For the positive to negative case, after the output direction of the welding machine's main circuit is switched, if the output current value of the welding machine is less than 10A, a 20µs delay is performed. If the output current value of the welding machine is less than -5A after the delay, it means that the welding machine does not need zero-crossing arc control at this time, and the control module has no output. If the output current value of the welding machine is greater than -5A after the delay, it means that the arc has been extinguished, and the drive module needs to be immediately controlled to turn on the first switch Q1 and the fourth switch Q4 and turn them off after a 20µs delay, so that the arc energy can be transferred to the welding machine's main circuit to complete the arc zero crossing. Arc control; In the case of negative to positive, after the output direction of the welding machine main circuit is switched, if the output current value of the welding machine is detected to be greater than -10A, a 20us delay is performed. If the output current value of the welding machine is greater than 5A after the delay, it means that the welding machine does not need zero-crossing arc control at this time, and the control module has no output. If the output current value of the welding machine is less than 5A after the delay, it means that the arc has been extinguished. It is necessary to immediately control the drive module to turn on the second switch Q2 and the third switch Q3 and turn them off after a 20us delay, so that the arc energy can be transmitted to the welding machine main circuit to complete the arc zero-crossing arc control. Example 2:

[0022] Please see Figure 1 and Figure 3 This embodiment provides an AC arc zero-dimensional arc control system, including a power supply module, a rectifier module, an energy storage module, a control module, a drive module, an execution module, and a transformer module. The power supply module, rectifier module, energy storage module, execution module, and transformer module are connected in sequence, and the control module, drive module, and execution module are connected in sequence. The input terminal of the power supply module is connected to the output terminal of the welding machine's main transformer, and the transformer module is coupled into the welding machine's main circuit.

[0023] Specifically, the power supply module includes a fifth capacitor C5, the rectifier module includes a first diode D1, a second diode D2, a third diode D3, and a fourth diode D4, the energy storage module includes a first resistor R1, a first capacitor C1, a second resistor R2, and a second capacitor C2, the execution module includes the same first and second switch control chips, and the transformer module includes a transformer T2. One end of the power supply module's output is connected in series with the fifth capacitor C5 and then connected to the positive terminal of the first diode D1. The other end of the power supply module's output is connected to the positive terminal of the second diode D2. The positive terminal of the first diode D1 is connected to the negative terminal of the third diode D3, and the negative terminal of the first diode D1 is connected to the positive terminal of the second diode D4. The negative terminal of diode D2 is connected to the negative terminal of diode D4, and the positive terminal of diode D4 is connected to the positive terminal of diode D3. The two ends of the first resistor R1 are connected to the negative terminal of diode D2 and one end of the first capacitor C1, respectively. The two ends of the second resistor R2 are connected to the positive terminal of diode D4 and one end of the second capacitor C2, respectively. The other ends of the first capacitor C1 and the second capacitor C2 are connected together. The first switch control chip and the second switch control chip form a half-bridge circuit. One end of the first capacitor C1 and the second capacitor C2 are connected to the input terminal of the half-bridge circuit. One end of transformer T2 is connected to the output terminal of the half-bridge circuit, and the other end is connected to the center tap of the welding machine's main transformer. The first switch control chip includes a first switch transistor Q1, a sixth diode D6, a sixth resistor R6, and a sixth capacitor C6. The cathode of the sixth diode D6 is connected to the collector of the first switch transistor Q1, and the anode of the sixth diode D6 is connected to the emitter of the first switch transistor Q1. One end of the sixth resistor R6 is connected to the collector of the first switch transistor Q1, and the other end of the sixth resistor R6 is connected to one end of the sixth capacitor C6. The other end of the sixth capacitor C6 is connected to the emitter of the first switch transistor Q1. The second switch control chip includes a second switch transistor Q2, a seventh diode D7, a seventh resistor R7, and a seventh capacitor C7. The cathode of the seventh diode D7 is connected to the collector of the second switch transistor Q2, and the anode of the seventh diode D7 is connected to the emitter of the second switch transistor Q2. The emitter of the first switch Q1 is connected to the collector of the second switch Q2, one end of the seventh resistor R7 is connected to the collector of the second switch Q2, the other end of the seventh resistor R7 is connected to one end of the seventh capacitor C7, and the other end of the seventh capacitor C7 is connected to the emitter of the second switch Q2; the emitter of the first switch Q1 is connected to the collector of the second switch Q2; the drive module is connected to the first switch Q1 and the second switch Q2 respectively; one end of the first capacitor C1 is connected to the collector of the first switch Q1, and one end of the second capacitor C2 is connected to the emitter of the second switch Q2; one end of the transformer T2 is connected to the connection circuit of the emitter of the first switch Q1 and the collector of the second switch Q2, and the other end is connected to the connection circuit of the other ends of the first capacitor C1 and the second capacitor C2.

[0024] The AC arc zero-dimensional arc control system described in this embodiment differs from the AC arc zero-dimensional arc control system in Embodiment 1 in the following ways: 1. The power supply module is different: when this power supply module collects electrical energy from the secondary winding of the welding machine's main transformer, it needs to simultaneously collect the center tap voltage of the main transformer; 2. The energy storage module is different: this energy storage module consists of two types of capacitors, one for positive and one for negative directions, used to store electrical energy in different directions respectively. The advantage of the AC arc zero-dimensional arc control system described in this embodiment is that it uses fewer switching devices, resulting in a cost advantage; the disadvantage is that the energy storage voltage is half that of the AC arc zero-dimensional arc control system in Embodiment 1, leading to a weaker zero-dimensional arc crossing capability.

[0025] Working principle: The power supply module receives AC power directly from the welding machine's main transformer. The rectifier module converts the AC power into DC power. The DC power then passes through resistors R1 and R2 to charge capacitors C1 and C2 in the energy storage module (while the welding machine's AC arc is outputting but not yet crossing zero, capacitors C1 and C2 are continuously charged until they are fully charged). In other words, the DC energy is stored in the energy storage module. When arc-maintaining energy output is needed, the half-bridge circuit in the actuator module discharges either capacitor C1 or C2 according to the direction of the AC arc crossing zero (positive to negative or negative to positive). The DC energy is finally coupled into the welding machine's main circuit through transformer T2 in the transformer module to complete the arc-maintaining control at zero arc crossing.

[0026] When the AC arc crosses zero, the control module handles two cases: positive to negative and negative to positive. When the arc crosses zero, the control module inputs a switching signal to the drive module. After the drive module converts the signal into a drive signal, it controls the first switch Q1 in the execution module to conduct for a fixed time and then turn it off in time. At this time, the transformer module relies on the DC power stored in the energy storage module to generate a current flowing from point A to point B in the transformer T2. At the same time, a voltage pulse is generated on the main circuit of the welding machine, with the welding gun end being higher than the base material end. This voltage pulse is used to assist the AC arc to switch from positive to negative, completing the arc zero-crossing arc control. When the signal changes from negative to positive, the control module inputs the switching signal to the drive module. After being converted into a drive signal by the drive module, the second switch Q2 in the control execution module is turned on for a fixed time and then turned off in time. At this time, the transformer module relies on the DC power stored in the energy storage module. A current will be generated in the transformer T2 from point B to point A. At the same time, a voltage pulse will be generated on the main circuit of the welding machine, with the base material end being higher than the welding gun end. This voltage pulse is used to assist the AC arc to change from negative to positive, completing the arc zero-dimensional arc control.

[0027] Please see Figure 7 and Figure 8 This embodiment also provides an AC arc zero-dimensional arc control method, applied to the AC arc zero-dimensional arc control system described in this embodiment, including: The control module contains software programs used to determine the direction and timing of zero-crossing arc control. Based on parameters such as the AC frequency and cleaning width preset by the welding machine, it completes the zero-crossing control of the welding machine's main circuit, that is, it completes the positive-to-negative or negative-to-positive output action at the correct time, and simultaneously begins monitoring the actual output current value of the welding machine.

[0028] The specific control process is as follows: For the positive to negative case, after the output direction of the welding machine's main circuit is switched, if the output current value of the welding machine is less than 10A, a 20µs delay is performed. If the output current value of the welding machine is less than -5A after the delay, it means that the welding machine does not need zero-crossing arc control at this time, and the control module has no output. If the output current value of the welding machine is greater than -5A after the delay, it means that the arc has been extinguished, and the drive module needs to be immediately controlled to turn on the first switching transistor Q1 and turn it off after a 20µs delay, so that the arc energy can be transferred to the welding machine's main circuit to complete the arc zero crossing. Arc control; In the case of negative to positive, after the output direction of the welding machine main circuit is switched, if the output current value of the welding machine is detected to be greater than -10A, a 20us delay is performed. If the output current value of the welding machine is greater than 5A after the delay, it means that the welding machine does not need zero-crossing arc control at this time, and the control module has no output. If the output current value of the welding machine is less than 5A after the delay, it means that the arc has been extinguished. It is necessary to immediately control the drive module to turn on the second switch Q2 and turn it off after a 20us delay, so that the arc energy can be transmitted to the welding machine main circuit to complete the arc zero-crossing arc control. Example 3:

[0029] Please see Figure 1 and Figure 4 This embodiment provides an AC arc zero-dimensional arc control system, including a power supply module, a rectifier module, an energy storage module, a control module, a drive module, an execution module, and a transformer module. The power supply module, rectifier module, energy storage module, execution module, and transformer module are connected in sequence, and the control module, drive module, and execution module are connected in sequence. The input terminal of the power supply module is connected to the output terminal of the welding machine's main transformer, and the transformer module is coupled into the welding machine's main circuit.

[0030] Specifically, further, the power supply module includes a fifth capacitor C5, the rectifier module includes a first diode D1, a second diode D2, a third diode D3, and a fourth diode D4, the energy storage module includes a first resistor R1 and a first capacitor C1, the execution module includes a first switch control chip, and the transformer module includes a transformer T2; one end of the output terminal of the power supply module is connected in series with the fifth capacitor C5 and then connected to the positive terminal of the first diode D1, the other end of the output terminal of the power supply module is connected to the positive terminal of the second diode D2, the positive terminal of the first diode D1 is connected to the negative terminal of the third diode D3, the negative terminal of the first diode D1 is connected to the negative terminal of the second diode D2, the positive terminal of the second diode D2 is connected to the negative terminal of the fourth diode D4, the positive terminal of the fourth diode D4 is connected to the positive terminal of the third diode D3, the two ends of the first resistor R1 are respectively connected to the negative terminal of the second diode D2 and one end of the first capacitor C1, the other end of the first capacitor C1 is connected to the positive terminal of the fourth diode D4, one end of the transformer T2 is connected to the output terminal of the first switch control chip, and the two ends of the first capacitor C1 are respectively connected to the input terminal of the first switch control chip and the other end of the transformer T2. The first switch control chip includes a first switch transistor Q1, a sixth diode D6, a sixth resistor R6, and a sixth capacitor C6. The cathode of the sixth diode D6 is connected to the collector of the first switch transistor Q1, and the anode of the sixth diode D6 is connected to the emitter of the first switch transistor Q1. One end of the sixth resistor R6 is connected to the collector of the first switch transistor Q1, and the other end of the sixth resistor R6 is connected to one end of the sixth capacitor C6. The other end of the sixth capacitor C6 is connected to the emitter of the first switch transistor Q1. The drive module is connected to the first switch transistor Q1. One end of the transformer T2 is connected to the emitter of the first switch transistor Q1, and one end of the first capacitor C1 is connected to the collector of the first switch transistor Q1. The other end of the first capacitor C1 is connected to the other end of the transformer T2.

[0031] The AC arc zero-dimensional arc control system described in this embodiment differs from the AC arc zero-dimensional arc control system in Embodiment 1 in that the execution module is different: this execution module is a single-tube type, which can only be used to apply a zero-dimensional arc when changing from positive to negative, or when changing from negative to positive, and cannot achieve bidirectional zero-dimensional arc. The advantage of the AC arc zero-dimensional arc control system described in this embodiment is that it uses fewer switching devices, resulting in a cost advantage; the disadvantage is that it can only achieve unidirectional zero-dimensional arc.

[0032] Working principle: The power module receives AC power directly from the welding machine's main transformer. The rectifier module converts the AC power into DC power. The DC power passes through the first resistor R1 to charge the first capacitor C1 in the energy storage module (while the welding machine's AC arc is outputting but not yet crossing zero, it continuously charges the first capacitor C1 until it is fully charged), thus storing the DC power energy in the energy storage module. When arc-maintaining energy output is needed, the first switch control chip in the drive execution module discharges the first capacitor C1. The DC power energy is finally coupled into the welding machine's main circuit through the transformer T2 in the transformer module to complete the arc-maintaining control when the arc crosses zero during positive-to-negative or negative-to-positive transitions.

[0033] This AC arc zero-dimensional arc control system can only be used to apply a zero-dimensional arc when switching from positive to negative, or vice versa. When used only for switching from positive to negative, the coupling direction from point A to point B of transformer T2 during welding machine assembly is the same as the coupling direction from the welding torch end to the base material end in the main circuit of the welding machine. Thus, when switching from positive to negative, the control module inputs a switching signal to the drive module. After being converted into a drive signal by the drive module, it controls the first switch Q1 in the execution module to conduct for a fixed time and then promptly turn it off. At this time, the transformer module relies on the DC power stored in the energy storage module, and a current flows from point A to point B in transformer T2. Simultaneously, a voltage pulse is generated in the main circuit of the welding machine, with the welding torch end higher than the base material end. This voltage pulse assists the AC arc in switching from positive to negative, completing the arc zero-dimensional arc control. Used only during negative-to-positive switching, when the welding machine is assembled, the coupling direction from point A to point B of transformer T2 is the same as the coupling direction from the base material end to the welding gun end in the main circuit of the welding machine. In this way, during negative-to-positive switching, the control module inputs the switching signal to the drive module. After being converted into a drive signal by the drive module, the second switch Q1 in the control execution module is turned on for a fixed time and then turned off in time. At this time, the transformer module relies on the DC power stored in the energy storage module. A current will be formed in transformer T2 from point A to point B. At the same time, a voltage pulse will be formed in the main circuit of the welding machine where the base material end is higher than the welding gun end. This voltage pulse is used to assist the AC arc to switch from negative to positive, completing the arc zero-dimensional arc control.

[0034] Please see Figure 9 and Figure 10 This embodiment also provides an AC arc zero-dimensional arc control method, applied to the AC arc zero-dimensional arc control system described in this embodiment, including: The control module contains software programs used to determine the direction and timing of zero-crossing arc control. Based on parameters such as the AC frequency and cleaning width preset by the welding machine, it completes the zero-crossing control of the welding machine's main circuit, that is, it completes the positive-to-negative or negative-to-positive output action at the correct time, and simultaneously begins monitoring the actual output current value of the welding machine.

[0035] The specific control process is as follows: For the positive to negative case, after the output direction of the welding machine's main circuit is switched, if the output current value of the welding machine is less than 10A, a 20µs delay is performed. If the output current value of the welding machine is less than -5A after the delay, it means that the welding machine does not need zero-crossing arc control at this time, and the control module has no output. If the output current value of the welding machine is greater than -5A after the delay, it means that the arc has been extinguished, and the drive module needs to be immediately controlled to turn on the first switching transistor Q1 and turn it off after a 20µs delay, so that the arc energy can be transferred to the welding machine's main circuit to complete the arc zero crossing. Arc control; In the case of negative to positive, after the output direction of the welding machine main circuit is switched, if the output current value of the welding machine is detected to be greater than -10A, a 20us delay is performed. If the output current value of the welding machine is greater than 5A after the delay, it means that the welding machine does not need zero-crossing arc control at this time, and the control module has no output. If the output current value of the welding machine is less than 5A after the delay, it means that the arc has been extinguished. It is necessary to immediately control the drive module to turn on the first switch Q1 and turn it off after a 20us delay, so that the arc energy can be transmitted to the welding machine main circuit to complete the arc zero-crossing arc control.

[0036] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. An AC arc zero-dimensional arc control system, characterized in that, The system includes a power supply module, a rectifier module, an energy storage module, a control module, a drive module, an execution module, and a transformer module. These modules are connected sequentially, as are the control module, drive module, and execution module. The input of the power supply module is connected to the output of the main transformer of the welding machine, and the transformer module is coupled into the main circuit of the welding machine. The power supply module receives AC power from the main transformer of the welding machine. The rectifier module converts the AC power into DC power, and the DC power energy is stored in the energy storage module. When the AC arc crosses zero and changes from positive to negative or from negative to positive, the control module inputs a switch signal to the drive module. The drive module converts the switch signal into a drive signal and controls the execution module to conduct for a fixed time before turning it off. The transformer module uses the DC power stored in the energy storage module to form a current with a certain direction, which causes a voltage pulse to be formed on the main circuit of the welding machine, where the welding torch end is higher than the base material end or the base material end is higher than the welding torch end. The voltage pulse assists in the AC arc changing from positive to negative or from negative to positive. The power supply module includes a fifth capacitor; the rectifier module includes a first diode, a second diode, a third diode, and a fourth diode; the energy storage module includes a first resistor and a first capacitor; the execution module includes the same first switch control chip, second switch control chip, third switch control chip, and fourth switch control chip; and the transformer module includes a transformer. One end of the power supply module's output is connected in series with the fifth capacitor and then connected to the anode of the first diode. The other end of the power supply module's output is connected to the anode of the second diode. The anode of the first diode is connected to the cathode of the third diode, the cathode of the first diode is connected to the cathode of the second diode, the anode of the second diode is connected to the cathode of the fourth diode, and the anode of the fourth diode is connected to the anode of the third diode. The two ends of the first resistor are respectively connected to the anode of the fourth diode and one end of the first capacitor. The other end of the first capacitor is connected to the cathode of the second diode. The first switch control chip, second switch control chip, third switch control chip, and fourth switch control chip form a full-bridge circuit. The two ends of the first capacitor are connected to the input of the full-bridge circuit, and the transformer is connected to the output of the full-bridge circuit.

2. The AC arc zero-dimensional arc control system according to claim 1, characterized in that, The first switch control chip includes a first switch transistor, a sixth diode, a sixth resistor, and a sixth capacitor. The cathode of the sixth diode is connected to the collector of the first switch transistor, and the anode of the sixth diode is connected to the emitter of the first switch transistor. One end of the sixth resistor is connected to the collector of the first switch transistor, and the other end of the sixth resistor is connected to one end of the sixth capacitor. The other end of the sixth capacitor is connected to the emitter of the first switch transistor. The second switch control chip includes a second switch transistor, a seventh diode, a seventh resistor, and a seventh capacitor. The cathode of the seventh diode is connected to the collector of the second switch transistor, and the anode of the seventh diode is connected to the emitter of the second switch transistor. One end of the seventh resistor is connected to the collector of the second switch transistor, and the other end of the seventh resistor is connected to one end of the seventh capacitor. The other end of the seventh capacitor is connected to the emitter of the second switch transistor. The third switch control chip includes a third switch transistor, an eighth diode, an eighth resistor, and an eighth capacitor. The cathode of the eighth diode is connected to the collector of the third switch transistor, and the anode of the eighth diode is connected to the emitter of the third switch transistor. One end of the eighth resistor is connected to the collector of the third switch transistor, and the other end of the eighth resistor is connected to the emitter of the third switch transistor. One end of the eighth capacitor is connected to the eighth capacitor, and the other end of the eighth capacitor is connected to the emitter of the third switching transistor. The fourth switch control chip includes a fourth switching transistor, a ninth diode, a ninth resistor, and a ninth capacitor. The negative terminal of the ninth diode is connected to the collector of the fourth switching transistor, and the positive terminal of the ninth diode is connected to the emitter of the fourth switching transistor. One end of the ninth resistor is connected to the collector of the fourth switching transistor, and the other end of the ninth resistor is connected to one end of the ninth capacitor. The other end of the ninth capacitor is connected to the emitter of the fourth switching transistor. The collectors of the first and third switching transistors are connected together, and the emitters of the second and fourth switching transistors are connected together. The emitter of the first switching transistor is connected to the collector of the second switching transistor, and the emitter of the third switching transistor is connected to the collector of the fourth switching transistor. The drive module is connected to the first, second, third, and fourth switching transistors respectively. The two ends of the first capacitor are connected to the collector of the first switching transistor and the emitter of the second switching transistor respectively. The transformer is connected to the connection circuit between the emitter of the first switching transistor and the collector of the second switching transistor, and between the emitter of the third switching transistor and the collector of the fourth switching transistor.

3. The AC arc zero-dimensional arc control system according to claim 1, characterized in that, The power supply module includes a fifth capacitor; the rectifier module includes a first diode, a second diode, a third diode, and a fourth diode; the energy storage module includes a first resistor, a first capacitor, a second resistor, and a second capacitor; the execution module includes the same first switch control chip and second switch control chip; and the transformer module includes a transformer. One end of the power supply module's output is connected in series with the fifth capacitor and then connected to the anode of the first diode. The other end of the power supply module's output is connected to the anode of the second diode. The anode of the first diode is connected to the cathode of the third diode, and the cathode of the first diode is connected to the cathode of the second diode. The anode of the second diode is connected to the cathode of the fourth diode, and the anode of the fourth diode is connected to the anode of the third diode. The two ends of the first resistor are respectively connected to the cathode of the second diode and one end of the first capacitor. The two ends of the second resistor are respectively connected to the anode of the fourth diode and one end of the second capacitor. The other ends of the first and second capacitors are connected together. The first switch control chip and the second switch control chip form a half-bridge circuit. One end of the first and second capacitors is connected to the input of the half-bridge circuit. One end of the transformer is connected to the output of the half-bridge circuit, and the other end is connected to the center tap of the welding machine's main transformer.

4. The AC arc zero-dimensional arc control system according to claim 3, characterized in that, The first switch control chip includes a first switching transistor, a sixth diode, a sixth resistor, and a sixth capacitor. The cathode of the sixth diode is connected to the collector of the first switching transistor, and the anode of the sixth diode is connected to the emitter of the first switching transistor. One end of the sixth resistor is connected to the collector of the first switching transistor, and the other end of the sixth resistor is connected to one end of the sixth capacitor. The other end of the sixth capacitor is connected to the emitter of the first switching transistor. The second switch control chip includes a second switching transistor, a seventh diode, a seventh resistor, and a seventh capacitor. The cathode of the seventh diode is connected to the collector of the second switching transistor, and the anode of the seventh diode is connected to the emitter of the second switching transistor. The circuit is as follows: one end of the seventh resistor is connected to the collector of the second switching transistor, the other end of the seventh resistor is connected to one end of the seventh capacitor, and the other end of the seventh capacitor is connected to the emitter of the second switching transistor; the emitter of the first switching transistor is connected to the collector of the second switching transistor; one end of the first capacitor is connected to the collector of the first switching transistor, and one end of the second capacitor is connected to the emitter of the second switching transistor; the drive module is connected to the first switching transistor and the second switching transistor respectively; one end of the transformer is connected to the connection circuit between the emitter of the first switching transistor and the collector of the second switching transistor, and the other end is connected to the connection circuit between the other ends of the first capacitor and the second capacitor.

5. The AC arc zero-dimensional arc control system according to claim 1, characterized in that, The power supply module includes a fifth capacitor; the rectifier module includes a first diode, a second diode, a third diode, and a fourth diode; the energy storage module includes a first resistor and a first capacitor; the execution module includes a first switch control chip; and the transformer module includes a transformer. One end of the power supply module's output is connected in series with the fifth capacitor and then connected to the anode of the first diode. The other end of the power supply module's output is connected to the anode of the second diode. The anode of the first diode is connected to the cathode of the third diode, the cathode of the first diode is connected to the cathode of the second diode, the anode of the second diode is connected to the cathode of the fourth diode, and the anode of the fourth diode is connected to the anode of the third diode. The two ends of the first resistor are respectively connected to the cathode of the second diode and one end of the first capacitor. The other end of the first capacitor is connected to the anode of the fourth diode. One end of the transformer is connected to the output of the first switch control chip, and the two ends of the first capacitor are respectively connected to the input of the first switch control chip and the other end of the transformer.

6. The AC arc zero-dimensional arc control system according to claim 5, characterized in that, The first switch control chip includes a first switch transistor, a sixth diode, a sixth resistor, and a sixth capacitor. The cathode of the sixth diode is connected to the collector of the first switch transistor, and the anode of the sixth diode is connected to the emitter of the first switch transistor. One end of the sixth resistor is connected to the collector of the first switch transistor, and the other end of the sixth resistor is connected to one end of the sixth capacitor. The other end of the sixth capacitor is connected to the emitter of the first switch transistor. The drive module is connected to the first switch transistor. One end of the transformer is connected to the emitter of the first switch transistor, and one end of the first capacitor is connected to the collector of the first switch transistor. The other end of the first capacitor is connected to the other end of the transformer.

7. A method for controlling the zero-dimensional arc of an alternating current arc, applied to the zero-dimensional arc control system of an alternating current arc as described in any one of claims 1 to 6, characterized in that, include: When the AC arc crosses zero and changes from positive to negative, if the output current value of the welding machine is detected to be less than the first preset value, a certain delay is made; If the output current value of the welding machine is detected to be less than the second preset value after the delay, the control module will not output; if the output current value of the welding machine is detected to be greater than the second preset value after the delay, the control module will input a switch signal to the drive module. The drive module will convert the switch signal into a drive signal and control the execution module to turn on for a fixed time and then turn off. The transformer module will use the DC power stored in the energy storage module to form a current in a certain direction, so that a voltage pulse is formed on the main circuit of the welding machine with the welding gun end higher than the base material end. The voltage pulse will assist the AC arc to turn from positive to negative. When the AC arc crosses zero and changes from negative to positive, if the output current value of the welding machine is detected to be greater than the third preset value, a certain delay is made; If the output current value of the welding machine is detected to be greater than the fourth preset value after the delay, the control module will not output; if the output current value of the welding machine is detected to be less than the fourth preset value after the delay, the control module will input a switch signal to the drive module. The drive module will convert the switch signal into a drive signal and control the execution module to turn on for a fixed time and then turn off. The transformer module will use the DC power stored in the energy storage module to form a current in a certain direction, so that a voltage pulse is formed on the main circuit of the welding machine with the base material end higher than the welding gun end. The voltage pulse will assist the AC arc to turn from negative to positive. The DC power stored in the energy storage module is obtained by converting AC power received from the main transformer of the welding machine by the power supply module into DC power through the rectifier module and then storing it in the energy storage module.

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