A thrust current control circuit, a thrust current control method, and a welding apparatus.

Abstract

This invention discloses a thrust current control circuit, a thrust current control method, and a welding apparatus. The thrust current control circuit includes: an amplification module connected to the output terminal of a welding machine, which generates a first voltage signal based on the arc voltage feedback signal from the welding machine output terminal; an adjustment module connected to the amplification module, which adjusts the amplification coefficient based on the arc voltage feedback signal, and amplifies the first voltage signal based on the adjusted amplification coefficient to generate a second voltage signal; the adjusted amplification coefficient gradually changes according to the arc voltage feedback signal; and a thrust signal generation module connected to the adjustment module, which generates a thrust current signal based on the second voltage signal. This invention, through the adjustment of the amplification coefficient, can achieve precise control of the thrust current signal, thereby further improving the dynamic response capability of the thrust current to changes in the arc voltage feedback signal.

Description

Technical Field

[0001] This invention relates to the field of welding technology, and in particular to a thrust current control circuit, a thrust current control method, and a welding apparatus. Background Technology

[0002] When manually arc welding cellulose electrodes, the combustion of cellulose in the electrode coating produces a large amount of gas, leading to poor arc stability. Secondly, cellulose electrodes are often used in overhead or vertical welding positions, where the molten pool tends to flow easily, and the droplet transfer pattern is more complex. Therefore, the welding power source needs to frequently apply thrust current to rapidly adjust the arc state to maintain arc stability.

[0003] There are currently two methods for applying thrust when manually arc welding cellulose electrodes. The first method involves applying a thrust current when the arc voltage drops to the thrust application point, with the thrust current increasing as the arc voltage decreases. The second method adds a thrust application stage to the first method, where the second stage begins when the arc voltage is low and close to a short circuit, and the rate of current change is greater than that of the first stage.

[0004] However, in cellulose electrode welding, the molten pool is prone to sag (vertical welding) or drip (overhead welding) under gravity. The droplet transfer mainly consists of short-circuit transfer and spray transfer, requiring a high dynamic response from the power supply to quickly adjust the thrust current and maintain the arc length. In existing thrust current control methods, when the arc voltage decreases and the thrust current increases, if the thrust current change rate is small, the arc is easily interrupted due to untimely adjustment; conversely, a large thrust current change rate can easily cause significant spatter, directly affecting the weld formation quality. In other words, the existing technology's ability to dynamically respond to changes in arc voltage during welding is insufficient. Summary of the Invention

[0005] This invention provides a thrust current control circuit, a thrust current control method, and a welding apparatus to solve the problem of insufficient dynamic response capability of the applied thrust current in the prior art according to the changes in arc voltage during the welding process.

[0006] According to one aspect of the present invention, a thrust current control circuit is provided, comprising:

[0007] The amplifier module is used to connect to the output end of the welding machine and generate the first voltage signal based on the arc voltage feedback signal from the output end of the welding machine.

[0008] An adjustment module, connected to the amplification module, is used to adjust the amplification coefficient according to the arc voltage feedback signal, and amplify the first voltage signal according to the adjusted amplification coefficient to generate a second voltage signal; the adjusted amplification coefficient changes gradually according to the arc voltage feedback signal.

[0009] A thrust signal generation module, connected to the adjustment module, is used to generate a thrust current signal based on the second voltage signal.

[0010] Optionally, the amplification module includes: a first resistor, a second resistor, a third resistor, and a first operational amplifier;

[0011] The arc voltage feedback signal is input to the first terminal of the first resistor;

[0012] The first terminal of the second resistor is connected to a DC voltage source;

[0013] The inverting input terminal of the first operational amplifier is connected to the second terminal of the first resistor, the second terminal of the second resistor, and the first terminal of the third resistor, respectively. The non-inverting input terminal of the first operational amplifier is connected to the ground terminal, and the output terminal of the first operational amplifier is connected to the second terminal of the third resistor.

[0014] Optionally, the amplification module further includes: a first diode;

[0015] The anode of the first diode is connected to the inverting input of the first operational amplifier, and the cathode of the first diode is connected to the output of the first operational amplifier. The first diode is used to turn off when the arc voltage feedback signal is less than a first preset value.

[0016] Optionally, the adjustment module includes: a second operational amplifier, wherein the second operational amplifier is a variable gain amplifier;

[0017] The positive input terminal of the second operational amplifier is connected to the output terminal of the first operational amplifier, the inverting input terminal of the second operational amplifier is connected to the ground terminal, the control terminal of the second operational amplifier receives the arc voltage feedback signal, and the gain coefficient of the second operational amplifier decreases as the arc voltage feedback signal decreases.

[0018] Optionally, the thrust signal generation module includes: a third diode, a fourth resistor, a fifth resistor, and a first capacitor;

[0019] The cathode of the third diode is connected to the output terminal of the adjustment module, and the anode of the third diode is connected to the first terminal of the fifth resistor. The third diode is used to conduct when the arc voltage feedback signal is greater than the second preset value.

[0020] The first end of the fourth resistor is connected to the output end of the adjustment module, and the second end of the fourth resistor is connected to the second end of the fifth resistor;

[0021] The first terminal of the first capacitor is connected to the second terminal of the fourth resistor, and the second terminal of the first capacitor is connected to the ground terminal.

[0022] Optionally, the thrust current control circuit further includes:

[0023] A voltage limiting module, wherein the first input terminal of the voltage limiting module is connected to the output terminal of the adjustment module, is used to control the magnitude of the second voltage signal to be equal to the third preset value when the second voltage signal is greater than the third preset value.

[0024] Optionally, the voltage limiting module includes: a second diode and a third operational amplifier;

[0025] The anode of the second diode is connected to the output terminal of the adjustment module;

[0026] The third operational amplifier receives a fourth preset value at its positive input terminal, the third operational amplifier is connected to the cathode of the diode at its inverting input terminal, and the output terminal of the third operational amplifier is connected to the inverting input terminal of the third operational amplifier.

[0027] Optional components also include: a microcontroller, a pulse width modulation controller, and a voltage feedback module;

[0028] The first output terminal of the microcontroller is connected to the second input terminal of the voltage limiting module, and a third preset value is input to the voltage limiting module; the second output terminal of the microcontroller is connected to the pulse width modulation controller, and a current command signal is input to the pulse width modulation controller.

[0029] The input terminal of the pulse width modulation controller is connected to the output terminal of the thrust signal generation module, and outputs a pulse width modulation signal according to the thrust current signal; wherein, the pulse width modulation signal is used to control the current of the welding power supply;

[0030] The input terminal of the voltage feedback module is used to connect to the output terminal of the welding machine; the output terminal of the voltage feedback module is connected to the input terminal of the amplification module and the control terminal of the adjustment module respectively, and outputs the arc voltage feedback signal to the amplification module and the adjustment module respectively.

[0031] According to another aspect of the present invention, a thrust current control method is provided, comprising:

[0032] The first voltage signal is generated based on the arc voltage feedback signal at the output of the welding machine;

[0033] Based on the arc voltage feedback signal, the amplification factor of the adjustment module is adjusted, and the first voltage signal is amplified according to the adjusted amplification factor to generate a second voltage signal; the adjusted amplification factor changes gradually according to the arc voltage feedback signal.

[0034] A thrust current signal is generated based on the second voltage signal.

[0035] According to another aspect of the present invention, a welding apparatus is provided, comprising a filter circuit, a rectifier-inverter circuit, and a thrust current control circuit as described in any of the above embodiments; the output terminal of the thrust current control circuit is connected to the control terminal of the rectifier-inverter circuit; the welding apparatus is capable of executing the thrust current control method as described in any of the above embodiments.

[0036] The technical solution of this invention involves adjusting the amplification factor of the adjustment module based on the arc voltage feedback signal. The amplified first voltage signal is then nonlinearly amplified using this amplification factor to generate a second voltage signal, which in turn generates a thrust current signal. The amplification factor directly affects the adjustment amplitude and speed of the thrust current during welding. By adjusting the amplification factor of the adjustment module according to the real-time arc voltage feedback signal, the thrust current can adapt to real-time changes in different working states and environmental conditions. In other words, this invention, through the adjustment of the amplification factor, can achieve precise control of the thrust current signal, thereby further improving the dynamic response capability of the thrust current to changes in the arc voltage feedback signal.

[0037] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0038] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0039] Figure 1 This is a schematic diagram of a thrust current control circuit provided in an embodiment of the present invention;

[0040] Figure 2 This is a schematic diagram of another thrust current control circuit provided in an embodiment of the present invention;

[0041] Figure 3 A schematic diagram of the dynamic response curve of thrust current provided for an embodiment of the present invention;

[0042] Figure 4 This is a schematic diagram of the external characteristic curve of the applied thrust current provided in an embodiment of the present invention;

[0043] Figure 5This is a schematic diagram of another thrust current control circuit provided in an embodiment of the present invention;

[0044] Figure 6 A flowchart of a thrust current control method provided in an embodiment of the present invention. Detailed Implementation

[0045] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0046] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0047] Figure 1 This is a schematic diagram of a thrust current control circuit provided in an embodiment of the present invention. This embodiment is applicable to the welding of cellulose welding rods. Figure 1 As shown, the thrust current control circuit includes:

[0048] Amplification module 110 is connected to the welding machine output terminal 140 and generates a first voltage signal based on the arc voltage feedback signal from the welding machine output terminal 140. Adjustment module 120, connected to amplification module 110, adjusts the amplification factor based on the arc voltage feedback signal, amplifies the first voltage signal based on the adjusted amplification factor, and generates a second voltage signal; the adjusted amplification factor gradually changes according to the arc voltage feedback signal. Thrust signal generation module 130, connected to adjustment module 120, generates a thrust current signal based on the second voltage signal.

[0049] Specifically, amplification module 110 refers to an electronic component used to enhance the strength of the input signal. In welding applications, the input of amplification module 110 is connected to the output of the welding machine 140 to receive and process arc voltage feedback signals related to the welding process. The arc voltage feedback signal refers to the voltage signal obtained from the output of the welding machine 140 during the welding process. The arc voltage feedback signal is used to monitor the stability and quality of the welding process. Changes in arc voltage can indicate information such as heat, molten pool state, and arc length during the welding process. The first voltage signal refers to the voltage signal output by the output of amplification module 110. For example, the first voltage signal can be a signal obtained by amplifying the arc voltage feedback signal. Adjustment module 120 refers to a component used to nonlinearly amplify the input first voltage signal according to the arc voltage feedback signal. The adjusted amplification factor refers to the amplification ratio dynamically adjusted in adjustment module 120 according to the input arc voltage feedback signal. That is, the amplification factor changes according to the real-time arc voltage feedback signal to adapt to different working states and environmental conditions. The adjusted amplification factor determines the degree to which the first voltage signal is amplified in the amplification module 110, thus affecting the amplitude of the generated second voltage signal. The second voltage signal refers to the voltage signal processed by the adjustment module 120. For example, the second voltage signal is a signal generated by multiplying the first voltage signal by the adjusted amplification factor. It can be expressed by the following formula:

[0050] V2 = V1 × K

[0051] Where V2 is the voltage value of the second voltage signal, V1 is the voltage value of the first voltage signal, and K is the adjusted amplification factor.

[0052] The thrust signal generation module 130 is the component responsible for converting the input voltage signal, such as the second voltage signal, into a thrust current signal. The thrust current signal refers to the current signal output by the thrust signal generation module 130, which is used to drive the thrust power supply to apply thrust current to the welding machine output terminal 140, thereby changing the nature of the welding arc.

[0053] In this embodiment of the invention, the amplification module 110 linearly amplifies the arc voltage feedback signal from the welding machine output terminal 140 to generate a first voltage signal. The adjustment module 120 nonlinearly amplifies the first voltage signal to generate a second voltage signal. The thrust signal generation module 130 converts the second voltage signal into a thrust current signal to adjust the current applied to the arc by the thrust power supply.

[0054] The technical solution of this invention involves adjusting the amplification factor of the adjustment module based on the arc voltage feedback signal. The amplified first voltage signal is then nonlinearly amplified using this amplification factor to generate a second voltage signal, which in turn generates a thrust current signal. The amplification factor directly affects the adjustment amplitude and speed of the thrust current during welding. By adjusting the amplification factor of the adjustment module according to the real-time arc voltage feedback signal, the thrust current can adapt to real-time changes in different working states and environmental conditions. In other words, this invention, through the adjustment of the amplification factor, can achieve precise control of the thrust current signal, thereby further improving the dynamic response capability of the thrust current to changes in the arc voltage feedback signal.

[0055] Figure 2 This is a schematic diagram of another thrust current control circuit provided in an embodiment of the present invention. Based on the above embodiments, optionally, the amplification module 110 includes: a first resistor R1, a second resistor R2, a third resistor R3, and a first operational amplifier U1A; the first terminal of the first resistor R1 receives an arc voltage feedback signal; the first terminal of the second resistor R2 is connected to a DC voltage source; the inverting input terminal of the first operational amplifier U1A is connected to the second terminals of the first resistor R1, the second terminal of the second resistor R2, and the first terminal of the third resistor R3, respectively; the non-inverting input terminal of the first operational amplifier U1A is connected to ground GND; and the output terminal of the first operational amplifier U1A is connected to the second terminal of the third resistor R3.

[0056] Specifically, the first operational amplifier U1A refers to an electronic component used to amplify voltage signals, having both an inverting input and a non-inverting input. The first operational amplifier U1A can amplify the arc voltage feedback signal into a first voltage signal. A DC voltage source refers to a power supply capable of providing a DC voltage. For example, a DC voltage source can provide a constant voltage less than zero.

[0057] In this embodiment of the invention, the first voltage signal can be obtained using the following formula:

[0058] V1 = -(V0 / r1 + V3 / r2)r3

[0059] Where V0 is the voltage value of the arc voltage feedback signal; V3 is the voltage value provided by the DC voltage source, where V3 is a negative number; r1 is the resistance value of the first resistor R1; r2 is the resistance value of the second resistor R2; and r3 is the resistance value of the third resistor R3.

[0060] Based on the above embodiments, alternatively, refer to the following: Figure 2The amplification module 110 further includes: a first diode D1; the anode of the first diode D1 is connected to the inverting input terminal of the first operational amplifier U1A, and the cathode of the first diode D1 is connected to the output terminal of the first operational amplifier U1A. The first diode D1 is used to turn off when the arc voltage feedback signal is less than a first preset value.

[0061] In this embodiment of the invention, if the arc voltage feedback signal is greater than or equal to a first preset value, the voltage at the anode of the first diode D1 is greater than or equal to the voltage at its cathode, and the first diode D1 conducts. After the first diode D1 conducts, it short-circuits the third resistor R3. At this time, the voltage at the output of the first operational amplifier U1A becomes 0, that is, the first voltage signal is 0. If the arc voltage feedback signal is less than the first preset value, the first diode D1 turns off. At this time, the first operational amplifier U1A amplifies the arc voltage feedback signal, that is, the first voltage signal is not 0. In other words, the first operational amplifier will only output a non-zero first voltage signal when the voltage value of the arc voltage feedback signal is less than the first preset value. Therefore, the subsequent circuit can output a thrust current signal to the welding machine output terminal 140 to adjust the properties of the welding arc.

[0062] The technical solution of this invention involves using a first diode to control a first operational amplifier to amplify the arc voltage feedback signal when its voltage value is less than a first preset value, thus outputting a non-zero first voltage signal. This invention ensures that when the arc voltage drops to the thrust reference point, i.e., the first preset value, the thrust current control circuit controls the thrust current source to output thrust current, thereby ensuring welding quality and efficiency.

[0063] Based on the above embodiments, alternatively, refer to the following: Figure 2 The adjustment module 120 includes: a second operational amplifier U2A, wherein the second operational amplifier U2A is a variable gain amplifier; the positive input terminal of the second operational amplifier U2A is connected to the output terminal of the first operational amplifier U1A, the inverting input terminal of the second operational amplifier U2A is connected to the ground terminal GND, the control terminal of the second operational amplifier U2A receives an arc voltage feedback signal, and the gain coefficient of the second operational amplifier U2A decreases as the arc voltage feedback signal decreases.

[0064] Specifically, the second operational amplifier U2A refers to an electronic component primarily used to amplify input signals. A variable gain amplifier is a special type of operational amplifier whose gain (amplification factor) can be adjusted according to external control signals or conditions. By adjusting the gain, a variable gain amplifier can flexibly change the amplification effect according to different input signal strengths or specific application requirements, ensuring optimal output signal quality and adaptability.

[0065] In this embodiment of the invention, the variable gain amplifier adjusts its gain coefficient according to the magnitude of the arc voltage feedback signal. As the voltage value of the arc voltage feedback signal decreases, the gain coefficient of the variable gain amplifier also decreases, thus weakening the amplification effect on the first voltage signal. However, since the voltage value of the first voltage signal increases linearly, the voltage value of the second voltage signal also increases, but at a slower rate.

[0066] The technical solution of this invention improves the dynamic response capability of the thrust current to the arc voltage feedback signal by using a variable gain amplifier to gradually increase the thrust current in a variable slope manner after it is reduced to a first preset value.

[0067] Based on the above embodiments, alternatively, refer to the following: Figure 2 The thrust signal generation module 130 includes: a third diode D3, a fourth resistor R4, a fifth resistor R5, and a first capacitor C1; the cathode of the third diode D3 is connected to the output terminal of the adjustment module 120, and the anode of the third diode D3 is connected to the first terminal of the fifth resistor R5. The third diode D3 is used to conduct when the arc voltage feedback signal is greater than a second preset value; the first terminal of the fourth resistor R4 is connected to the output terminal of the adjustment module 120, and the second terminal of the fourth resistor R4 is connected to the second terminal of the fifth resistor R5; the first terminal of the first capacitor C1 is connected to the second terminal of the fourth resistor R4, and the second terminal of the first capacitor C1 is connected to the ground terminal GND.

[0068] Specifically, the second preset value refers to the preset value that the arc voltage exceeds when the molten droplet falls off the welding machine output terminal 140. When the arc voltage rises to a value greater than or equal to the first preset value, the first operational amplifier U1A outputs a first voltage signal of 0, meaning the thrust current value drops to 0. When the arc voltage rises above the second preset value, the third diode D3 conducts, the first capacitor C1 discharges, and the thrust current value slowly decreases to 0. Therefore, the second preset value is greater than the first preset value.

[0069] In this embodiment of the invention, when the voltage value of the arc voltage feedback signal is less than or equal to the second preset value, the third diode D3 is turned off, and the first capacitor C1 is charged; when the voltage value of the arc voltage feedback signal is greater than the second preset value, the third diode D3 is turned on, and the second capacitor is discharged. The charging path of the first capacitor C1 is: charging from the output terminal of the adjustment module 120 through the fourth resistor R4. The discharging path of the first capacitor C1 is: charging from the output terminal of the adjustment module 120 through the fourth resistor R4 and the fifth resistor R5. Since the resistance of the discharging path of the first capacitor C1 is smaller than the resistance of the charging path, the discharging speed is faster than the charging speed.

[0070] Figure 3 This is a schematic diagram of the dynamic response curve of thrust current provided for an embodiment of the present invention. Figure 3 As shown, the vertical axis represents current in A, and the horizontal axis represents time in ms. During the time interval from the first time point T1 to the second time point T2, the thrust current increases from the second current I2 to the first current I1, but the rate of increase gradually slows down. During the time interval from the second time point T2 to the third time point T3, the thrust current gradually decreases from the first current I1 to the second current I2.

[0071] Figure 4 This is a schematic diagram of the external characteristic curve of an applied thrust current provided in an embodiment of the present invention. Figure 4 As shown, the vertical axis represents voltage (V), and the horizontal axis represents current (A). When the arc voltage feedback signal drops to the first voltage U1, the thrust current is applied. When the arc voltage feedback signal drops to the second voltage U2, the first stage of thrust current application is completed, and the system enters the constant current stage, outputting a constant first current I1.

[0072] The technical solution of this invention, through the cooperation of the first capacitor, the fourth resistor, the fifth resistor and the third diode, achieves a smooth transition of the thrust current in the circuit after the molten droplet falls.

[0073] Based on the above embodiments, alternatively, refer to the following: Figure 2 The thrust current control circuit also includes a voltage limiting module, the first input terminal of which is connected to the output terminal of the adjustment module 120, for controlling the magnitude of the second voltage signal to be equal to the third preset value when the second voltage signal is greater than the third preset value.

[0074] Specifically, a voltage limiting module refers to a circuit component used to limit the voltage range of an input signal. The voltage limiting module can limit the magnitude of the thrust current. The third preset value refers to a set voltage threshold; when the second voltage signal exceeds this value, the voltage limiting module will activate its protection mechanism to limit the voltage value of the second voltage signal to the third preset value.

[0075] Based on the above embodiments, alternatively, refer to the following: Figure 2 The voltage limiting module includes: a second diode D2 and a third operational amplifier U1B; the anode of the second diode D2 is connected to the output terminal of the adjustment module 120; a fourth preset value is input to the positive input terminal of the third operational amplifier U1B, the inverting input terminal of the third operational amplifier U1B is connected to the cathode of the diode, and the output terminal of the third operational amplifier U1B is connected to the inverting input terminal of the third operational amplifier U1B.

[0076] Specifically, the fourth preset value refers to the preset voltage value input to the anode input terminal of the third operational amplifier U1B, which is set according to the third preset value.

[0077] In this embodiment of the invention, when the value of the second voltage signal is greater than the third preset value, the second diode D2 is turned on. The third operational amplifier controls the voltage at the cathode of the second diode D2 to be equal to the fourth preset value. Therefore, the voltage value of the second voltage signal is clamped at the fourth preset value plus the voltage drop across the second diode D2. That is, the third preset value is equal to the fourth preset value plus the voltage drop across the second diode D2.

[0078] The technical solution of this invention uses a second diode to clamp the voltage, ensuring that the voltage value of the second voltage signal cannot exceed a third preset value, thereby limiting the maximum thrust current and effectively improving the safety of the thrust current control circuit.

[0079] Figure 5 This is a schematic diagram of another thrust current control circuit provided in an embodiment of the present invention. Based on the above embodiments, as follows... Figure 5 As shown, optionally, it also includes: a microcontroller 161, a pulse width modulation controller 162, and a voltage feedback module 163; the first output terminal of the microcontroller 161 is connected to the second input terminal of the voltage limiting module, and inputs a third preset value to the voltage limiting module; the second output terminal of the microcontroller 161 is connected to the pulse width modulation controller 162, and inputs a current given signal to the pulse width modulation controller 162; the input terminal of the pulse width modulation controller 162 is connected to the output terminal of the thrust signal generation module 130, and outputs a pulse width modulation signal according to the thrust current signal; wherein, the pulse width modulation signal is used to control the current of the welding power supply; the input terminal of the voltage feedback module 163 is used to connect to the welding machine output terminal 140; the output terminal of the voltage feedback module 163 is connected to the input terminal of the amplification module 110 and the control terminal of the adjustment module 120 respectively, and outputs arc voltage feedback signals to the amplification module 110 and the adjustment module 120 respectively.

[0080] Specifically, microcontroller 161 refers to a small computing device. Microcontroller 161 is used to perform control tasks, receiving input signals and outputting control signals according to a preset program. For example, microcontroller 161 can be a single-chip microcomputer. Pulse width modulation controller 162 refers to the circuit responsible for generating pulse width modulation signals. Pulse width modulation controller 162 can adjust the duty cycle of the output signal according to the input thrust current signal to control the current of the welding power source. The pulse width modulation signal refers to the control signal generated by pulse width modulation controller 162. The pulse width modulation signal is used to control the current of the welding power source, and precise control of the output current is achieved by adjusting the duty cycle of the signal. Voltage feedback module 163 refers to a component used to monitor the arc voltage at the output terminal 140 of the welding machine, and its output arc voltage feedback signal is transmitted to amplification module 110 and adjustment module 120.

[0081] In this embodiment of the invention, the voltage feedback module 163 transmits the acquired arc voltage feedback signal to the amplification module 110 and the adjustment module 120. The microcontroller 161 transmits the set third preset value to the voltage limiting module. The thrust signal generation module 130 generates a thrust current signal, which is transmitted to the pulse width modulation controller 162. The pulse width modulation controller 162 generates a pulse width modulation signal to control the magnitude of the output current of the thrust current source.

[0082] Figure 6 This is a flowchart illustrating a thrust current control method provided in an embodiment of the present invention. Figure 6 As shown, the method includes:

[0083] S210. Generate the first voltage signal based on the arc voltage feedback signal at the output end of the welding machine.

[0084] S220. Based on the arc voltage feedback signal, adjust the amplification factor of the adjustment module, and amplify the first voltage signal according to the adjusted amplification factor to generate the second voltage signal; the adjusted amplification factor changes gradually according to the arc voltage feedback signal.

[0085] S230, Generate a thrust current signal based on the second voltage signal.

[0086] In this embodiment of the invention, the amplification module linearly amplifies the arc voltage feedback signal from the welding machine output to generate a first voltage signal. The adjustment module nonlinearly amplifies the first voltage signal to generate a second voltage signal. The thrust signal generation module converts the second voltage signal into a thrust current signal to adjust the current applied to the arc by the thrust power supply.

[0087] The technical solution of this invention involves adjusting the amplification factor based on the arc voltage feedback signal using an adjustment module. The amplified first voltage signal is then nonlinearly amplified using this amplification factor to generate a second voltage signal, which in turn generates a thrust current signal. By adjusting the amplification factor, this invention enables fine-tuning of the thrust current signal, thereby further improving the dynamic response capability of the thrust current to changes in the arc voltage feedback signal.

[0088] This invention also provides a welding apparatus. (Continue to refer to...) Figure 5 The welding device includes a filter circuit 164, a rectifier-inverter circuit 165, and a thrust current control circuit provided in any embodiment of the present invention; the output terminal of the thrust current control circuit is connected to the control terminal of the rectifier-inverter circuit 165; the welding device is capable of executing the thrust current control method provided in any embodiment of the present invention.

[0089] Specifically, filter circuit 164 refers to a circuit used to remove high-frequency noise or unwanted frequency components from a signal. Filter circuit 164 is used to ensure the smoothness and stability of the output signal. Rectifier-inverter circuit 165 refers to a circuit used to convert AC signals to DC signals, or vice versa. The rectifier section of filter circuit 164 converts AC signals to DC signals, while the inverter section converts DC signals back to AC signals, thus achieving power output that adapts to different load requirements.

[0090] In this embodiment of the invention, the filter circuit is connected to the AC power supply terminal of the welding device for filtering; the rectifier-inverter circuit is connected to the filter circuit for rectifying AC power into DC power and outputting it to the output terminal of the welding machine, or for inverting DC power from the output terminal of the welding machine into AC power and outputting it to the AC power supply terminal.

[0091] The welding apparatus provided in the embodiments of the present invention can execute the thrust current control method provided in any embodiment of the present invention, and has the corresponding functional modules and beneficial effects of the execution method.

[0092] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0093] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A thrust current control circuit, characterized in that, include: The amplifier module is used to connect to the output end of the welding machine and generate the first voltage signal based on the arc voltage feedback signal from the output end of the welding machine. An adjustment module, connected to the amplification module, is used to adjust the amplification coefficient according to the arc voltage feedback signal, and amplify the first voltage signal according to the adjusted amplification coefficient to generate a second voltage signal; the adjusted amplification coefficient changes gradually according to the arc voltage feedback signal. A thrust signal generation module, connected to the adjustment module, is used to generate a thrust current signal based on the second voltage signal; The amplification module includes: a first resistor, a second resistor, a third resistor, and a first operational amplifier; The arc voltage feedback signal is input to the first terminal of the first resistor; The first terminal of the second resistor is connected to a DC voltage source; The inverting input terminal of the first operational amplifier is connected to the second terminal of the first resistor, the second terminal of the second resistor, and the first terminal of the third resistor, respectively. The non-inverting input terminal of the first operational amplifier is connected to the ground terminal. The output terminal of the first operational amplifier is connected to the second terminal of the third resistor. The amplification module further includes: a first diode; The anode of the first diode is connected to the inverting input of the first operational amplifier, and the cathode of the first diode is connected to the output of the first operational amplifier. The first diode is used to turn off when the arc voltage feedback signal is less than a first preset value. The adjustment module includes: a second operational amplifier, wherein the second operational amplifier is a variable gain amplifier; The positive input terminal of the second operational amplifier is connected to the output terminal of the first operational amplifier, the inverting input terminal of the second operational amplifier is connected to the ground terminal, the control terminal of the second operational amplifier receives the arc voltage feedback signal, and the gain coefficient of the second operational amplifier decreases as the arc voltage feedback signal decreases. The thrust signal generation module includes: a third diode, a fourth resistor, a fifth resistor, and a first capacitor; The cathode of the third diode is connected to the output terminal of the adjustment module, and the anode of the third diode is connected to the first terminal of the fifth resistor. The third diode is used to conduct when the arc voltage feedback signal is greater than the second preset value. The first end of the fourth resistor is connected to the output end of the adjustment module, and the second end of the fourth resistor is connected to the second end of the fifth resistor; The first terminal of the first capacitor is connected to the second terminal of the fourth resistor, and the second terminal of the first capacitor is connected to the ground terminal. The thrust current control circuit also includes: A voltage limiting module, wherein the first input terminal of the voltage limiting module is connected to the output terminal of the adjustment module, is used to control the magnitude of the second voltage signal to be equal to the third preset value when the second voltage signal is greater than the third preset value; The voltage limiting module includes: a second diode and a third operational amplifier; The anode of the second diode is connected to the output terminal of the adjustment module; The third operational amplifier receives a fourth preset value at its positive input terminal, the third operational amplifier is connected to the cathode of the second diode at its inverting input terminal, and the output terminal of the third operational amplifier is connected to the inverting input terminal of the third operational amplifier. It also includes: a microcontroller, a pulse width modulation controller, and a voltage feedback module; The first output terminal of the microcontroller is connected to the second input terminal of the voltage limiting module, and a third preset value is input to the voltage limiting module; the second output terminal of the microcontroller is connected to the pulse width modulation controller, and a current command signal is input to the pulse width modulation controller. The input terminal of the pulse width modulation controller is connected to the output terminal of the thrust signal generation module, and outputs a pulse width modulation signal according to the thrust current signal; wherein, the pulse width modulation signal is used to control the current of the welding power supply; The input terminal of the voltage feedback module is used to connect to the output terminal of the welding machine; the output terminal of the voltage feedback module is connected to the input terminal of the amplification module and the control terminal of the adjustment module respectively, and outputs the arc voltage feedback signal to the amplification module and the adjustment module respectively.

2. A thrust current control method, applied to the thrust current control circuit of claim 1, characterized in that, include: The first voltage signal is generated based on the arc voltage feedback signal at the output of the welding machine; Based on the arc voltage feedback signal, the amplification factor of the adjustment module is adjusted, and the first voltage signal is amplified according to the adjusted amplification factor to generate a second voltage signal; the adjusted amplification factor changes gradually according to the arc voltage feedback signal. A thrust current signal is generated based on the second voltage signal.

3. A welding apparatus, characterized in that, The device includes a filter circuit, a rectifier-inverter circuit, and the thrust current control circuit as described in claim 1; the output terminal of the thrust current control circuit is connected to the control terminal of the rectifier-inverter circuit; the welding device is capable of executing the thrust current control method as described in claim 2.

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