Welding control method and device, electronic equipment and storage medium

Abstract

The invention relates to the technical field of welding automation control, and discloses a welding control method and device, electronic equipment and a storage medium. The method comprises the steps that a high-frequency detection signal is injected into a welding loop, and a complex impedance phase angle is calculated according to feedback high-frequency voltage and current components; in a short-circuit state, keeping access of a main flat wave inductor connected in series in a loop, and monitoring the time gradient of a complex impedance phase angle in real time; and when the gradient value meets the preset necking judgment condition, it is judged that the molten drops enter the critical necking state, dynamic demagnetizing bypass branches connected to the two ends of the main flat wave inductor in parallel are controlled to be conducted so as to bypass the main flat wave inductor, and meanwhile power output is stopped. According to the method, the anti-interference capability of necking identification is improved by utilizing the phase angle gradient characteristics, and the time constant of a circuit topology reconstruction loop is dynamically changed, so that the current rapid attenuation before arc breaking is realized while the detection signal-to-noise ratio is ensured, and the occurrence of welding spatter is remarkably reduced.

Description

Technical Field

[0001] This invention relates to the field of welding automation control technology, specifically to welding control methods and devices, electronic equipment, and storage media. Background Technology

[0002] In gas metal arc welding (GMAW), short-circuit transfer is one of the most common droplet transfer methods. Weld spatter is a key indicator for evaluating the quality of short-circuit transfer welding. Spatter mainly occurs at the moment the molten droplet bridge breaks. If a large current is maintained in the welding circuit at this time, the strong electromagnetic contraction force will cause the liquid bridge to break explosively, scattering molten metal onto the workpiece surface. This not only affects the aesthetics of the weld formation but also increases the workload of subsequent cleaning. Therefore, the key to achieving low-spatter welding lies in accurately capturing the necking moment of the molten droplet bridge and rapidly reducing the welding current before the liquid bridge physically breaks.

[0003] Currently, the detection of droplet necking mainly relies on monitoring welding voltage or equivalent resistance. However, in actual welding conditions, the contact between the welding wire and the contact tip is not stable. Affected by factors such as wire feeding vibration, thermal expansion, and surface oxide layer, the contact resistance will exhibit random and drastic fluctuations. These fluctuations in contact resistance are often on the same order of magnitude as the resistance changes caused by liquid bridge necking, making it difficult for the control system to accurately extract the effective signal characterizing necking from the background noise. Insufficient detection accuracy directly leads to deviations in current control timing, resulting in frequent premature arc termination or arc termination failure.

[0004] Furthermore, the inductance parameters in the welding circuit have a dual impact on the control effect, constituting a contradiction in the existing technology. On the one hand, in order to suppress current ripple and maintain arc stiffness and stability during the arc-burning phase, the welding power supply usually needs to be connected in series with a large smoothing inductor. On the other hand, according to circuit principles, a large inductance will significantly increase the time constant of the circuit, hindering rapid changes in current. When the control system detects a compression signal and attempts to cut off the current, due to the presence of a large inductance, the current cannot decay to a low value rapidly in the microsecond-level later stage of the short circuit. This physical lag in the rate of current decline means that even if the system accurately detects the necking signal, spatter is often unavoidable due to insufficient energy dissipation. Although existing electronic inductance control technology has a certain degree of adjustment capability, it is often difficult to achieve hardware-level transient switching from a high-inductance stable arc state to a low-inductance fast-off state within an extremely short short-circuit period. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a welding control method and apparatus, electronic equipment, and storage medium, which solves the technical problems of inaccurate necking detection due to contact resistance interference and large spatter due to the large inductance of the circuit hindering the rapid attenuation of current in existing short-circuit transition welding.

[0006] To achieve the above objectives, the present invention provides the following technical solution: The first aspect of the present invention provides a welding control method, comprising the following steps: During the welding process, a high-frequency detection signal is continuously injected into the welding circuit, and the voltage and current data of the welding circuit are acquired. The high-frequency voltage component and high-frequency current component corresponding to the frequency of the high-frequency detection signal are separated from the voltage and current data, and the real-time complex impedance phase angle of the welding circuit is calculated based on the high-frequency voltage component and the high-frequency current component.

[0007] When a short circuit is detected during welding, the power semiconductor switch is kept in the off state, and the gradient value of the complex impedance phase angle with respect to time is calculated.

[0008] The gradient value is compared with a preset necking threshold. When the gradient value meets the preset triggering condition, the molten droplet bridge is determined to have entered a critical necking state.

[0009] In response to the molten droplet bridge entering a critical necking state, the welding power supply is controlled to stop outputting power, and at the same time, the power semiconductor switch is controlled to switch from an open state to a closed conducting state to bypass the main smoothing inductor.

[0010] When the voltage of the welding circuit is detected to recover to above the arc ignition voltage threshold, the power semiconductor switch is controlled to open and the power output of the welding power source is restored.

[0011] This technical solution solves the problem that traditional resistance-based monitoring methods cannot accurately distinguish between contact resistance fluctuations and physical necking of liquid bridges by combining high-frequency injection with complex impedance phase angle gradient monitoring. Specifically, it monitors the real-time complex impedance phase angle of the welding circuit. It can reflect the ratio relationship between inductive reactance and resistive component, and its calculation basis is as follows: ; Among them, the numerator term The cross product magnitude of the voltage and current vectors is related to the reactive power component of the circuit, thus reflecting the inductive impedance characteristics; the denominator term... It represents the dot product of the voltage vector and the current vector, which is related to the active power component of the circuit, and thus reflects the resistive impedance characteristics.

[0012] Furthermore, in order to extract this mutation feature, the present invention introduces a phase angle gradient. As the basis for the judgment, its calculation method is as follows: ; in, This represents the phase gradient value at the k-th sampling time. This represents the phase angle of the complex impedance at the current moment; This represents the historical phase angle value shifted forward by m sampling periods; is the system sampling period; m is the differential span coefficient. The value of this differential span coefficient m is used to adjust the smoothness of the gradient calculation against noise and the response speed to abrupt signals.

[0013] In terms of control strategy, this invention adjusts the loop time constant by dynamically changing the hardware topology. In the initial stage of a short circuit, the main smoothing inductor is connected to maintain a large loop inductance, which helps improve the signal-to-noise ratio of phase angle detection. After necking is confirmed, the main smoothing inductor is bypassed by closing the power semiconductor switch, causing the welding circuit to switch from a high-inductance mode to a fast-break mode. At this time, the current decay time constant of the loop is changed from... Mutation It satisfies: A second aspect of the present invention provides a welding control device, comprising an inverter main power unit, a high-frequency injection unit, a dynamic inductor topology unit, a signal acquisition unit, and a central control unit.

[0014] The inverter main power unit is configured to output welding current.

[0015] The high-frequency injection unit is configured to inject high-frequency detection signals into the welding circuit.

[0016] The dynamic inductor topology unit is connected in series in the welding circuit. Its structure includes a main smoothing inductor and a dynamic demagnetizing bypass branch connected in parallel across the main smoothing inductor. The dynamic demagnetizing bypass branch includes a power semiconductor switch and a power dissipation element connected in series.

[0017] The signal acquisition unit is configured to acquire voltage and current data of the welding circuit. The central control unit is configured to execute the above-described welding control method.

[0018] A third aspect of the present invention provides a computer device including a processor and a memory, wherein the memory stores a computer program, and when the computer program is executed by the processor, it implements the method described in the first aspect of the present invention.

[0019] A fourth aspect of the present invention provides a computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, it implements the method described in the first aspect of the present invention.

[0020] This invention provides a welding control method and apparatus, electronic equipment, and storage medium. It has the following beneficial effects: 1. This invention effectively solves the problem of traditional resistance detection methods being susceptible to interference from contact resistance fluctuations by introducing a high-frequency injection and complex impedance phase angle gradient monitoring mechanism. By utilizing the skin effect under high-frequency signals and the high sensitivity of complex impedance phase angle to the geometric deformation of the liquid bridge, combined with gradient algorithm to extract abrupt change features, it can accurately identify the critical necking state before the liquid bridge physically breaks. This detection method shields the noise interference of non-inductive factors in the welding circuit, improves the recognition accuracy of microscopic liquid bridge morphological changes, and achieves the effect of passive detection and pre-judgment.

[0021] 2. This invention utilizes dynamic inductor topology units to achieve real-time reconstruction of the welding rebound time constant, significantly reducing welding spatter. After confirming the necking signal, the main smoothing inductor is short-circuited by turning on the bypass switch, instantly switching the welding circuit to a fast-break mode dominated by the line distributed inductance. This operation reduces the circuit current decay time constant to the microsecond level, ensuring that the current has dropped to an extremely low level before the liquid bridge is disconnected. This eliminates the electromagnetic contraction force required to maintain a high-current arc, allowing the molten droplet to transition smoothly mainly under the action of surface tension, avoiding explosive metal spatter caused by the failure to turn off the current in time.

[0022] 3. This invention, through hardware coordination of monitoring and control, balances the requirements of signal detection sensitivity and arc control dynamics. During the short-circuit monitoring stage, the main smoothing inductor is retained, and the large basic inductance ensures the signal-to-noise ratio of high-frequency response, avoiding the detection signal being submerged under low inductance. During the arc breaking stage, the main inductor is bypassed, solving the physical limitation that a large inductor hinders the rapid decrease of current. This phased topology control strategy ensures both the reliability of necking identification and the flexibility of the arc breaking process, improving the overall stability and forming quality of the welding process. Attached Figure Description

[0023] Figure 1 This is a flowchart of the method of the present invention; Figure 2 This is a system architecture diagram of the present invention; Figure 3 This is a schematic diagram of the computer device structure of the present invention.

[0024] Among them, 110 is the main power unit of the inverter; 120 is the high-frequency injection unit; 130 is the dynamic inductor topology unit; 131 is the main smoothing inductor; 132 is the dynamic demagnetizing bypass branch; 133 is the power semiconductor switch; 134 is the energy-consuming component; 140 is the signal acquisition unit; and 150 is the central control unit. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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 are within the scope of protection of the present invention. Example

[0026] Please see the appendix Figure 1 - Appendix Figure 2 The present invention provides a welding control device, including an inverter main power unit 110, a high frequency injection unit 120, a dynamic inductor topology unit 130, a signal acquisition unit 140, and a central control unit 150.

[0027] The inverter main power unit 110 is used to convert the input power frequency AC power into DC or pulse current required for welding. The output terminal of the inverter main power unit 110 is connected to the dynamic inductor topology unit 130. The output terminal of the dynamic inductor topology unit 130 is connected to the welding torch and the workpiece to be welded through the welding cable to form a welding circuit.

[0028] The high-frequency injection unit 120 is coupled between the output terminal of the inverter main power unit 110 and the welding circuit. The high-frequency injection unit 120 is configured to superimpose a detection signal with a specific frequency onto the welding circuit. The detection signal is a high-frequency AC voltage signal or a high-frequency AC current signal, and its frequency value is set in the range of 20kHz to 100kHz. The frequency value is set to avoid the switching frequency and its higher harmonic frequencies of the inverter main power unit 110.

[0029] A dynamic inductor topology unit 130 is connected in series in the welding circuit. The dynamic inductor topology unit 130 includes a main smoothing inductor 131 and a dynamic demagnetizing bypass branch 132 connected in parallel across the main smoothing inductor 131. The dynamic demagnetizing bypass branch 132 is composed of a power semiconductor switch 133 and a power dissipation element 134 connected in series. The power semiconductor switch 133 is selected as an insulated-gate bipolar transistor or a metal-oxide-semiconductor field-effect transistor. The power dissipation element 134 is selected as a high-power non-inductive resistor or a transient suppression diode.

[0030] The signal acquisition unit 140 is connected to the welding circuit and is configured to acquire the terminal voltage signal and circuit current signal of the welding circuit in real time. The signal acquisition unit 140 includes a high-bandwidth Hall current sensor and a voltage sensor, and its signal output terminal is connected to the central control unit 150.

[0031] The central control unit 150 is electrically connected to the inverter main power unit 110, the high frequency injection unit 120, the dynamic inductor topology unit 130, and the signal acquisition unit 140. The central control unit 150 is configured to receive the voltage and current signals fed back by the signal acquisition unit 140, and send control commands to the inverter main power unit 110 and the dynamic inductor topology unit 130 according to the processing results.

[0032] See attached document Figure 2 This invention provides a welding control method, the method comprising: S100. During the welding process, a high-frequency detection signal is continuously injected into the welding circuit through the high-frequency injection unit. The high-frequency detection signal is superimposed on the welding current output by the inverter main power unit. S200: The voltage and current data of the welding circuit are acquired through the signal acquisition unit, and the high-frequency voltage component and high-frequency current component corresponding to the frequency of the high-frequency detection signal are separated from the voltage and current data. S300. Calculate the real-time complex impedance phase angle of the welding circuit based on the separated high-frequency voltage and current components. S400 When the welding circuit voltage is detected to be lower than the preset short circuit threshold, it is confirmed that the short circuit has entered the initial stage. The power semiconductor switch in the dynamic inductor topology unit is controlled to remain in the open state, so that the welding current flows through the main smoothing inductor. S500: During the short-circuit state, calculate the gradient value of the complex impedance phase angle with respect to time in real time; S600. Compare the gradient value with the preset necking judgment threshold. When the absolute value of the gradient value is greater than or equal to the necking judgment threshold, determine that the molten droplet bridge has entered the critical necking state and generate a topology switching trigger signal. S700, in response to the topology switching trigger signal, controls the inverter main power unit to stop outputting power, and simultaneously controls the power semiconductor switch to switch from the open state to the closed conduction state; S800 bypasses the main smoothing inductor by closing the power semiconductor switch, reducing the time constant of the welding circuit and causing the current flowing through the molten droplet bridge to decay until the molten droplet bridge breaks under the action of surface tension. S900: When the welding circuit voltage is detected to recover to above the arc ignition voltage threshold, the control power semiconductor switch is turned off, and the inverter main power unit is controlled to resume output.

[0033] In this embodiment, the injection of the high-frequency detection signal and the real-time calculation of the complex impedance parameters specifically include the following steps: A composite welding output current is constructed by generating a sinusoidal AC signal with a set frequency and amplitude simultaneously with the output of conventional welding energy from the inverter main power unit. This sinusoidal AC signal is superimposed onto the DC bus or output terminal of the welding circuit through an isolation coupling circuit, ensuring that the total current flowing through the welding circuit includes both a DC welding component and a high-frequency AC detection component. The frequency setting value of the high-frequency AC detection component is specified below. The preferred frequency band is 20kHz to 100kHz. This band is chosen to be away from the background noise frequency of the welding arc and the switching frequency of the inverter, while ensuring that the skin effect at this frequency has a significant impedance response to changes in the cross-sectional area of ​​the liquid bridge conductor. The amplitude of the high-frequency AC probe component is controlled between 1% and 5% of the welding base current to avoid having a substantial impact on the heat input of the weld pool.

[0034] The high-frequency signal components are acquired and separated. The broadband current sensor and voltage sensor in the signal acquisition unit monitor the real-time current of the welding circuit. and terminal voltage Synchronous sampling is performed. The sampled analog signal undergoes analog-to-digital conversion (ADC). This ADC process is well-known to those skilled in the art and will not be elaborated upon here. The digital filter module within the central control unit performs bandpass filtering on the converted digital signal. The digital filter module is configured as a finite impulse response (FIR) filter or an infinite impulse response (IOR) filter, with its center frequency locked at a set frequency. This filtering process removes DC components, power frequency interference, and inverter switching noise, extracting only the high-frequency voltage components containing the detection frequency. and high-frequency current components .

[0035] Based on the principle of quadrature phase-locked loop (QLL), the complex impedance components are calculated. To obtain high-precision phase information, this embodiment employs a digital quadrature phase-locked loop amplification algorithm to demodulate the separated high-frequency components. Specifically, the system internally generates two reference signals of the same frequency, namely, in-phase reference signals. and quadrature reference signals High-frequency voltage components Multiplying the voltage by the in-phase reference signal and the quadrature reference signal respectively, and then passing the result through a low-pass filter, yields the in-phase component of the voltage. and orthogonal components Similarly, for high-frequency current components... Perform the same demodulation process to obtain the in-phase component of the current. and orthogonal components .

[0036] Calculate the real-time complex impedance phase angle. Based on the in-phase and quadrature components obtained from the demodulation, calculate the welding circuit at the current moment. Complex impedance phase angle The calculation process first determines the phase difference between the voltage vector and the current vector. Mathematically, this complex impedance phase angle is... The ratio of inductive reactance to high-frequency equivalent resistance in the welding circuit is characterized, and the specific calculation is based on the following formula: ; Among them, the numerator term The cross product magnitude of the voltage and current vectors is related to the reactive power component of the circuit, thus reflecting the inductive impedance characteristics; the denominator term... It represents the dot product of the voltage vector and the current vector, which is related to the active power component of the circuit, and thus reflects the resistive impedance characteristics.

[0037] Based on the calculated complex impedance phase angle Data smoothing and preprocessing are performed. Considering potential transient electromagnetic interference at the welding site, the central control unit adjusts the continuously calculated complex impedance phase angle. A moving average filter or median filter is applied to output a stable phase angle data stream for subsequent gradient calculation. This phase angle data stream directly reflects the inductance in the welding circuit. With high frequency resistor The dynamic ratio change eliminates the interference of pure resistive voltage drop on the absolute value of the detection result.

[0038] In this embodiment, the process of monitoring the phase angle gradient and extracting features after the welding circuit enters a short-circuit state specifically includes the following steps: Short-circuit state confirmation and topology locking: The central control unit performs threshold judgment on the welding end voltage fed back by the signal acquisition unit. When the terminal voltage is detected to be continuously lower than the preset short-circuit judgment voltage threshold, the welding process is judged to switch from the arcing stage to the short-circuit transition stage. At the same time as confirming the entry into the short-circuit state, the central control unit sends a locking command to the dynamic inductor topology unit, forcibly controlling the power semiconductor switch in it to remain in the off state. At this time, the welding main circuit is in a high inductive impedance mode, and the main smoothing inductor is fully connected to the circuit. The purpose of this control logic is to maintain a large inductance base of the welding circuit. According to the principle of complex impedance phase angle calculation, a large circuit inductance makes the phase angle offset of the high-frequency detection signal significant, thereby ensuring the signal sensitivity and signal-to-noise ratio of subsequent detection of small inductance changes of the liquid bridge.

[0039] A sliding window for phase angle data is established. During the short circuit duration, the central control unit allocates a first-in-first-out data buffer in its internal memory to store the continuously sampled complex impedance phase angle data sequence. This data buffer is configured as a sliding window with a window length of [missing information]. The sampling frequency is set according to the control response requirements, typically covering a time span of tens to hundreds of microseconds. Whenever a new phase angle calculation value is available... During generation, the data is pushed into a queue and the earliest data point is removed, ensuring that the data within the window is always updated in a timely manner.

[0040] To extract the abrupt change characteristic of liquid bridge necking from slowly changing contact resistance interference, the system does not directly use the absolute value of the phase angle. Instead, it calculates the rate of change of the phase angle with respect to time, i.e., the phase angle gradient. In digital control systems, this gradient calculation is achieved through discrete difference operations, and the specific operational logic is shown in the following formula: ; in, This represents the phase gradient value at the k-th sampling time. This represents the phase angle of the complex impedance at the current moment; This represents the historical phase angle value shifted forward by m sampling periods; is the system sampling period; m is the differential span coefficient. The value of this differential span coefficient m is used to adjust the smoothness of the gradient calculation against noise and the response speed to abrupt signals.

[0041] Gradient signal magnitude processing and denoising: Since inductance changes in the welding circuit may fluctuate positively or negatively due to cable swaying or arc morphology variations, and inductance changes caused by fluid bridge necking are directional, the system processes the calculated gradient values ​​to simplify the decision logic. The absolute value or the specific polarity change direction is extracted. In addition, the original gradient signal is subjected to amplitude limiting filtering to remove non-physical spike pulses caused by occasional packet loss of high-frequency injection signal or electromagnetic interference, and a smoothed gradient feature signal is obtained. This gradient feature signal directly reflects the nonlinear change rate of the inductive impedance component relative to the resistive impedance component in the welding circuit, and is the core basis for subsequent identification of droplet necking singularities.

[0042] In this embodiment, the process of identifying the singularity of droplet necking based on phase angle gradient specifically includes the following steps: A mapping relationship between the geometry of the liquid bridge and the phase angle gradient was established. In the later stage of the droplet short-circuit transition, under the electromagnetic contraction force generated by the short-circuit current flowing through the liquid bridge, radial contraction occurs in the middle of the liquid bridge, forming a necking region. As the necking cross-sectional area approaches the critical fracture point, the resistance value of the liquid bridge... The inductance increases sharply due to the decrease in cross-sectional area; simultaneously, the high-frequency inductance value of the liquid bridge... It also changes with the geometry, but due to the skin effect of high-frequency current and the physical characteristics of the logarithmic change of conductor geometric inductance, the rate of change of inductance and the rate of change of resistance are asynchronous.

[0043] This asynchrony leads to the inductive reactance of the welding circuit. With resistive components The ratio undergoes a nonlinear abrupt change at the necking critical point, which is reflected in the complex impedance phase angle, manifested as the phase angle. A sharp inflection point appears on the time axis, which mathematically corresponds to the phase gradient. The extreme point, namely the necking singularity defined in this invention, is a physical feature that differs from the linear impedance change caused only by the fluctuation of the contact resistance of the conductive tip, which is usually manifested as a gradual drift of the phase angle rather than an abrupt change.

[0044] The neck constriction detection threshold is set, and the central control unit pre-stores the neck constriction detection threshold. The threshold The value of is related to the material and diameter of the welding wire, as well as the frequency of the high-frequency injection signal.

[0045] In practice, this threshold is set to be greater than the background noise gradient value of the welding circuit under normal short-circuit conditions, and corresponds to the phase angle change rate when the liquid bridge diameter shrinks to the micrometer level. The physical significance of this threshold is to define whether the liquid bridge has reached the irreversible deformation stage before physical disconnection.

[0046] During the gradient comparison decision, the central control unit will calculate the phase gradient value in real time. With neck retraction determination threshold Logical comparison is performed. Considering the possible differences in the direction of phase change at different frequencies, this embodiment uses the absolute value of the gradient for decision-making. The decision logic satisfies the following relationship: ; When the above inequality conditions are not met, the system determines that the molten droplet is still in a stable necking process and continues to maintain the original control state. When the above inequality conditions are met, the system confirms that it has captured the necking singularity, indicating that the liquid bridge is about to break but has not yet physically separated.

[0047] A hardware-level trigger signal is generated. Once the necking singularity is detected, the central control unit immediately generates a high-priority topology switching trigger signal. This signal acts directly on the hardware drive circuit without undergoing multi-stage filtering and delay at the software level. The generation time of this trigger signal precedes the physical breakage of the liquid bridge. This advance provides a necessary time window for subsequent circuit topology switching and current attenuation, ensuring that the circuit energy has been completely discharged before the arc reignites. This mechanism represents a technological breakthrough from post-event detection to pre-event prediction.

[0048] In this embodiment, the dynamic inductor topology switching and flexible arc-breaking control process specifically includes the following steps: When performing a topology switching action, the central control unit immediately outputs a turn-on command to the power semiconductor switch in the dynamic inductor topology unit upon receiving the topology switching trigger signal, and simultaneously outputs a pulse blocking command to the inverter main power unit. This action causes the dynamic demagnetizing bypass branch connected in parallel across the main smoothing inductor to turn on instantly. The main smoothing inductor, which was originally connected in series in the welding main circuit, is short-circuited by this bypass branch. In terms of electrical connection, this means that the main smoothing inductor no longer acts as a series impedance element in the welding circuit, but forms an independent closed self-inductance circuit, or is diverted by the energy-consuming element in the bypass branch.

[0049] The reconfiguration loop time constant refers to the time constant of the current decay in the welding loop before the switching occurs, at the instant the power semiconductor switch is turned on, when the equivalent electrical topology of the welding loop undergoes physical reconfiguration. Main smoothing inductor Dominate, satisfy ,in This is the total resistance of the circuit.

[0050] because Typically, a larger value is chosen to maintain arc stability, leading to The current is too large to decrease rapidly within microseconds. After switching, the main smoothing inductor is bypassed, and the equivalent inductance of the welding circuit drops rapidly to include only the distributed inductance of the line. At this point, the welding circuit enters fast-break mode, and its current decay time constant abruptly changes to [a certain level]. The calculation relationship is as follows: ; in, This represents the resistance value of the energy-consuming component in the dynamic demagnetization bypass branch. Because... ,and The introduction of this increases the loop damping, making much smaller This change in physical properties resolves the contradiction in traditional control between the advantages of large inductance for arc detection and stability and the advantages of small inductance for rapid arc breaking.

[0051] The forced decay of the droplet current is controlled by an extremely small fast-break mode time constant. Welding current flowing through the molten droplet bridge The current decays rapidly in an exponential manner. Within a tiny time window before the liquid bridge physically disconnects, the current value drops rapidly from the short-circuit peak to near zero amperes or extremely low micro-arc current levels. Simultaneously, the magnetic field energy originally stored in the main smoothing inductor is no longer forcibly coupled to the arc load, but is instead dissipated or fed back into the local circuit through the closed power semiconductor switch and energy-consuming components. This process cuts off the energy source that maintains the high temperature and strong electromagnetic contraction force of the liquid bridge.

[0052] Silent transition dominated by surface tension. This occurs as current flows through the liquid bridge. When it drops to its lowest point, the electromagnetic contraction force acts on the neck of the liquid bridge. With the square of the current The liquid bridge disappears rapidly. At this point, it is no longer subject to radial electromagnetic compression and Joule thermal explosion. Under the influence of the molten metal's own surface tension and gravity, it is smoothly broken and transitions into the molten pool. This process avoids metal splashing caused by the instantaneous vaporization and explosion of the liquid bridge under high current, achieving a cold transition in a physical sense.

[0053] Arc reignition and topology reset occur. After the molten droplet detaches, the physical contact between the welding wire and the workpiece breaks, and the gap voltage rapidly recovers. The signal acquisition unit continuously monitors the terminal voltage. When the terminal voltage is detected to rise to the set arc ignition voltage threshold, it is confirmed that the arc has been reignited.

[0054] At this point, the central control unit cancels the on command of the power semiconductor switch, restoring it to the off state; simultaneously, it releases the pulse blockade on the inverter main power unit, restoring normal welding current output. With the power semiconductor switch off, the main smoothing inductor... The welding circuit is reconnected, and the system returns to the high inductive impedance mode. The large inductance characteristics are used to suppress the current overshoot in the early stage of arc reignition, ensuring the arc stiffness and stability in the subsequent arcing stage, and preparing for the phase angle detection of the next short-circuit cycle.

[0055] To verify the technical effectiveness of the welding control method proposed in this invention under actual working conditions, especially its performance in suppressing spatter, this embodiment constructs a specific welding test scenario for quantitative comparative experiments.

[0056] The test scenario is set up as follows: The base material was Q235 carbon steel plate with a thickness of 5mm, and the above-mentioned plate welding test was conducted. Solid welding wire with a diameter of 1.2mm was used. The shielding gas was 100% CO2 gas, with a gas flow rate set at 15L / min. This gas composition typically results in significant short-circuit transfer spatter due to its high arc stiffness and high thermal conductivity, allowing for thorough testing of the system's control performance.

[0057] The welding process parameters are set as follows: average welding current 160A, average welding voltage 19.5V, welding speed 50cm / min, and dry extension length maintained at 12mm.

[0058] The system parameters of this embodiment are configured as follows: the high-frequency injection signal frequency is set to 50kHz, and the injection amplitude is 1V. In the dynamic inductor topology unit, the main smoothing inductor... The value is 300 The equivalent distributed inductance of the loop after the dynamic demagnetization bypass branch is turned on. Approximately 5 Threshold for determining neck retraction Based on the previously calibrated data.

[0059] For comparison, two control groups were set up: Control group 1: A traditional constant voltage control power supply was used, with the loop inductance fixed at 300Ω. No dynamic topology control was applied; natural short-circuit transition was used instead.

[0060] Control group 2: A welding power source using resistance sensing (electronic inductance) technology, utilizing the rate of change of resistance. The system detects necking, but the hardware topology is fixed, and current is suppressed only by adjusting the output voltage through the inverter.

[0061] Within the same welding time (60 seconds of continuous welding), metal spatter particles scattered on both sides of the weld were collected using a fume hood and a collection tray. The spatter generation rate (unit: g / min) was calculated after weighing. The test results are as follows: Control group 1 (traditional constant voltage): Due to the inability of the current to decrease rapidly in the later stages of the short circuit, the current reached approximately 280A at the moment of liquid bridge fracture, resulting in violent explosive spatter. The measured spatter generation rate was 3.85 g / min, and a large number of fine particles adhered to the weld surface.

[0062] Control group 2 (resistance detection + soft switching): Although it can detect necking to some extent, it is affected by fluctuations in contact resistance, leading to premature or delayed arc termination due to misjudgment. Furthermore, because the loop inductance cannot be physically bypassed, the current decay rate is limited (approximately 150 A / ms). The measured spatter generation rate is 1.42 g / min, mainly manifested as large particle spatter.

[0063] Embodiment of the present invention: through phase angle gradient The timing of the liquid bridge diameter shrinking to approximately 300 μm was precisely pinpointed, immediately triggering a topology switch. Oscilloscope waveforms showed that after hardware bypass was enabled, the welding current decay rate exceeded 500 A / ms, and the current at the moment of physical liquid bridge fracture had decreased to below 15 A. The measured spatter generation rate was only 0.35 g / min, a reduction of approximately 90% compared to control group 1 and approximately 75% compared to control group 2. The weld formation was continuous and smooth, with almost no visible spatter adhesion.

[0064] The above quantitative data shows that the present invention significantly reduces the spatter rate in a 100% CO2 welding environment through hardware collaboration of high-frequency complex impedance detection and dynamic inductor topology, achieving a welding effect with extremely low spatter.

[0065] Combined with appendix Figure 3This application also provides a computer device, including: a processor and a memory, wherein the memory stores a computer program executable by the processor, and the computer program performs the method described above when executed by the processor.

[0066] The present invention also provides a storage medium storing a computer program, which is executed by a processor to perform the method described above.

[0067] The storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as Static Random Access Memory, Electrically Erasable Programmable Read-Only Memory (EEPROM), Erasable Programmable Read-Only Memory (EPROM), Programmable Red-Only Memory (PROM), Read-Only Memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk.

[0068] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A welding control method, characterized in that, Includes the following steps: During the welding process, a high-frequency detection signal is continuously injected into the welding circuit, and the voltage and current data of the welding circuit are acquired. The high-frequency voltage component and high-frequency current component corresponding to the frequency of the high-frequency detection signal are separated from the voltage data and current data, and the real-time complex impedance phase angle of the welding circuit is calculated based on the high-frequency voltage component and the high-frequency current component. When a short circuit is detected during welding, the power semiconductor switch is kept in the off state, and the gradient value of the complex impedance phase angle with respect to time is calculated. The gradient value is compared with a preset necking threshold. When the gradient value meets the preset triggering condition, the droplet bridge is determined to have entered a critical necking state. In response to the molten droplet bridge entering a critical necking state, the welding power supply is controlled to stop outputting power, and at the same time, the power semiconductor switch is controlled to switch from an open state to a closed conducting state to bypass the main smoothing inductor. When the voltage of the welding circuit is detected to recover to above the arc ignition voltage threshold, the power semiconductor switch is controlled to open and the power output of the welding power source is restored.

2. The welding control method according to claim 1, characterized in that, The continuous injection of high-frequency detection signals into the welding circuit includes: A sinusoidal AC signal with a frequency of 20kHz to 100kHz is superimposed on the DC output terminal of the welding circuit, and the frequency of the sinusoidal AC signal avoids the inverter switching frequency of the welding power supply.

3. The welding control method according to claim 1, characterized in that, The calculation of the real-time complex impedance phase angle of the welding circuit based on the high-frequency voltage component and the high-frequency current component includes: The high-frequency voltage component and the high-frequency current component are quadratured using in-phase reference signal and quadrature reference signal, respectively, to obtain in-phase voltage component, quadrature voltage component, in-phase current component and quadrature current component. Based on the in-phase voltage component, the quadrature voltage component, the in-phase current component, and the quadrature current component, the phase difference between the voltage vector and the current vector is calculated, and the phase difference is used as the phase angle of the real-time complex impedance.

4. The welding control method according to claim 1, characterized in that, The calculation of the gradient value of the complex impedance phase angle with respect to time includes: Establish a sliding window containing complex impedance phase angle data from multiple consecutive sampling times; Calculate the difference between the complex impedance phase angle at the current moment and the complex impedance phase angle at a historical moment in the sliding window; Dividing the difference by the corresponding time interval yields the gradient value of the complex impedance phase angle with respect to time.

5. The welding control method according to claim 1, characterized in that, The step of comparing the gradient value with a preset necking threshold, and determining that the molten droplet bridge has entered a critical necking state when the gradient value meets a preset triggering condition, includes: Calculate the absolute value of the gradient; Determine whether the absolute value of the gradient value is greater than or equal to the necking determination threshold; If so, the gradient value is determined to meet the preset triggering condition, confirming that the necking singularity of the molten droplet bridge has been captured.

6. The welding control method according to claim 1, characterized in that, The control of the power semiconductor switch from an open state to a closed on state to bypass the main smoothing inductor includes: Turning on the power semiconductor switch switches the current flow path of the welding circuit from flowing through the main smoothing inductor to flowing through the dynamic demagnetizing bypass branch. The energy-consuming element in the dynamic demagnetizing bypass branch is used to increase the loop damping and reduce the current decay time constant of the welding circuit to the fast-break mode time constant dominated by the distributed inductance of the line.

7. The welding control method according to claim 1, characterized in that, The step of detecting a short circuit during welding includes: Compare the voltage data of the welding circuit with a preset short-circuit voltage threshold; When the voltage data is lower than the preset short-circuit voltage threshold, it is confirmed that the welding has entered a short-circuit state, and a lockout disconnect command is sent to the power semiconductor switch until it is determined that the molten droplet bridge has entered a critical necking state.

8. A welding control device, applied to the welding control method according to any one of claims 1-9, characterized in that, include: The inverter main power unit is used to output welding current; A high-frequency injection unit is used to inject high-frequency detection signals into the welding circuit; A dynamic inductor topology unit is connected in series in the welding circuit. The dynamic inductor topology unit includes a main smoothing inductor and a dynamic demagnetizing bypass branch connected in parallel across the main smoothing inductor. The dynamic demagnetizing bypass branch includes a power semiconductor switch and a power dissipation element connected in series. The signal acquisition unit is used to acquire voltage and current data of the welding circuit; The central control unit is used to control problems that occur during the welding process.

9. A computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the method as described in any one of claims 1-7.

10. A storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the method as described in any one of claims 1-7.

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