An arc regulation method and system based on a rotating magnetic field

Abstract

The application relates to the technical field of arc control, and discloses an arc regulation and control method and system based on a rotating magnetic field, which comprises the following steps: arranging 2N electromagnets uniformly in the circumferential direction of a welding gun; selecting a current working mode according to the regulation and control target of arc energy; in response to the need to improve the arc energy concentration, exciting adjacent electromagnet pairs in turn according to a cycle, and passing opposite currents through the electromagnet pairs to generate a periodic one-side Lorenz force on the arc plasma, which is directed to the axis of the welding gun, so that the arc is continuously compressed and driven in the circumferential direction; and in response to the need to regulate the arc energy distribution, synchronously exciting multiple groups of electromagnet pairs that are symmetrically distributed in space to form a multi-lobe symmetrical magnetic field, so that a radially symmetrical compression force is applied to the arc, and the compression direction is rotated in the circumferential direction through periodic rotation of the groups. The application realizes high-precision adaptive regulation and control of the arc shape and energy distribution, and significantly improves the stability of the welding process and the weld forming quality.

Description

Technical Field

[0001] This invention relates to the field of electric arc control technology, and in particular to an electric arc control method and system based on a rotating magnetic field. Background Technology

[0002] In modern high-precision welding, the stability, morphology, and energy distribution of the electric arc directly affect the weld quality. Applying an external magnetic field to control the arc is an effective method, using the Lorentz force to alter the trajectory of charged particles and thus achieve active control over the arc's behavior.

[0003] Existing magnetic control technologies mainly include transverse magnetic fields, longitudinal magnetic fields, rotating magnetic fields, and sharp-angle magnetic fields, which respectively achieve unidirectional oscillation, symmetrical rotation, or multi-pole compression of the electric arc. However, these methods have obvious limitations: transverse and longitudinal magnetic fields can only achieve oscillation in one direction, making it difficult to simultaneously control melt depth and melt width; traditional rotating magnetic fields cause overall arc shift and energy dispersion due to symmetrical excitation, easily leading to spatter or edge biting; although fixed sharp-angle magnetic fields can compress the arc, the symmetry of the force field limits the fine control of local dynamic response; in addition, existing devices are mostly in fixed modes and lack the ability to adaptively switch according to process parameters.

[0004] Therefore, a new magnetic field control mechanism is urgently needed to stabilize the electric arc while improving energy concentration and control precision. Summary of the Invention

[0005] To address the limitations of existing magnetically controlled electric arc technology in achieving high-frequency unilateral periodic compression, which results in dispersed arc energy and a lack of adaptive control capabilities, this invention proposes an arc control method and system based on a rotating magnetic field.

[0006] According to a first aspect of the present invention, an arc control method based on a rotating magnetic field is provided, comprising: 2N electromagnets are evenly arranged around the welding torch, where N is an integer ≥ 2; Select the current operating mode based on the target of controlling the electric arc energy; In response to the need to increase the concentration of electric arc energy, the first mode is selected and adjacent electromagnet pairs are excited sequentially in a periodic manner. Currents in opposite directions are passed through the electromagnet pairs to generate a periodic unilateral Lorentz force pointing towards the welding torch axis on the electric arc plasma, thereby realizing continuous unilateral compression and circumferential rotation drive of the electric arc. In response to the need to regulate the energy distribution of the electric arc, a second mode is selected and multiple sets of spatially symmetrically distributed electromagnet pairs are excited simultaneously to form a multi-lobed symmetrical magnetic field, so as to apply a radially symmetrical compressive force to the electric arc, and the compression direction is rotated circumferentially by periodically rotating the excitation groups.

[0007] In some embodiments, in the first mode, the two electromagnets in the excited electromagnet pair are spaced 90° apart on the circumference.

[0008] In some embodiments, in the first mode, the switching angle of the excited electromagnet pair is 360° / (2N).

[0009] In some embodiments, the sequential excitation of adjacent electromagnet pairs in a periodic manner includes: Only one pair of electromagnets is excited during each excitation period, and the excited electromagnets are rotated sequentially between different excitation periods, so that the single-sided compression position moves sequentially along the circumference.

[0010] In some embodiments, the sequential excitation of adjacent electromagnet pairs in a periodic manner includes: Multiple pairs of adjacent electromagnets are excited simultaneously during each excitation period, and the excited electromagnet combinations are rotated cyclically between different excitation periods, so that multiple compression positions rotate synchronously in the circumferential direction.

[0011] In some embodiments, the synchronous excitation of multiple spatially symmetrically distributed pairs of electromagnets includes: Synchronous excitation is provided by multiple pairs of electromagnets that are mirror- or rotationally symmetrically distributed on a circumference, with each pair containing at least two electromagnets to form a multi-lobed symmetrical magnetic field.

[0012] In some embodiments, the arc control method based on a rotating magnetic field further includes: Based on at least one of welding current, arc voltage, welding speed, visual signal of molten pool or arc sensing signal, the first mode and the second mode are dynamically switched, and the amplitude, frequency and phase of the excitation current are adjusted.

[0013] In some embodiments, adjusting the amplitude, frequency, and phase of the excitation current includes: Arc stability is determined based on arc voltage fluctuation rate; If the arc voltage fluctuation rate exceeds the first preset threshold, the frequency of the excitation current is increased and the current amplitude is increased until the arc voltage fluctuation rate falls back to below the second preset threshold.

[0014] According to a second aspect of the present invention, an arc control system based on a rotating magnetic field is also provided for use in the method described in any of the foregoing embodiments, comprising: 2N electromagnets are evenly arranged around the circumference of the welding torch, where N is an integer ≥ 2; Multiple independently controllable excitation power supplies are connected to each of the electromagnets; A magnetically controlled arc controller is used to select the current working mode according to the target of arc energy regulation and to control the excitation power supply to apply excitation current to the electromagnet. In response to the need to increase the concentration of arc energy, a first mode is selected, in which the magnetically controlled arc controller controls the excitation power supply to periodically excite adjacent pairs of electromagnets and applies currents in opposite directions to the electromagnets to generate a periodic unilateral Lorentz force pointing towards the welding torch axis on the arc plasma, thereby achieving continuous unilateral compression and circumferential rotation drive of the arc. In response to the need to regulate the arc energy distribution, a second mode is selected, in which the magnetically controlled arc controller controls the excitation power supply to synchronously excite multiple sets of spatially symmetrically distributed pairs of electromagnets to form a multi-lobed symmetrical magnetic field, thereby applying a radially symmetrical compressive force to the arc and rotating the compression direction circumferentially by periodically alternating the excitation groups.

[0015] In some embodiments, the frequency range of the excitation current of the excitation power supply is 1~500Hz.

[0016] This invention has at least the following beneficial effects: It proposes an arc control method based on a rotating magnetic field. Through multi-mode electromagnetic excitation and automatic selection of working modes under different conditions, it achieves high-precision adaptive control of arc morphology and energy distribution, significantly improving the stability of the welding process and the quality of weld formation. Specifically, by uniformly arranging 2N electromagnets around the welding torch and selecting the current working mode according to the target of arc energy control, to increase arc energy concentration, the first mode is selected. By periodically exciting adjacent pairs of electromagnets and passing them with reverse current, a periodic unilateral Lorentz force pointing towards the welding torch axis is generated on the arc plasma, achieving continuous unilateral compression and high-frequency circumferential rotation drive of the arc, significantly improving the arc energy concentration. To control the arc energy distribution, the second mode is selected. By synchronously exciting multiple sets of spatially symmetrically distributed pairs of electromagnets and periodically rotating the excitation groups, a rotating multi-lobed symmetrical magnetic field is formed, dynamically changing the long axis direction of the elliptical arc to adjust the arc energy distribution, thereby actively controlling the heat flow distribution of the molten pool, which is beneficial to improving weld formation. The automatic selection of the working mode for the control target of electric arc energy enables adaptive optimization for different welding conditions, ensuring that the electric arc always works in the best state, and greatly improving the adaptability of the welding process and the yield.

[0017] In addition, an arc control system based on a rotating magnetic field, as described in this invention, can also achieve the above-mentioned technical effects, which will not be elaborated here. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other embodiments can be obtained based on these drawings without creative effort.

[0019] Figure 1 A flowchart of an arc control method based on a rotating magnetic field, provided as an embodiment of the present invention; Figure 2 A schematic diagram of an arc control system based on a rotating magnetic field, provided as an embodiment of the present invention; Figure 3 A top view of an electric arc under force without any external magnetic field, provided as an embodiment of the present invention; Figure 4 A schematic diagram of an electromagnet pair in a first mode provided for an embodiment of the present invention; Figure 5 Another schematic diagram of the excitation of the electromagnet pair in a first mode according to an embodiment of the present invention; Figure 6 A schematic diagram of a pair of electromagnets in a second mode provided for an embodiment of the present invention; Figure 7 This is a schematic diagram of an existing fixed-angle magnetic field mode; Figure 8 This is a schematic diagram of the existing transverse magnetic field mode; Figure 9 This is a schematic diagram of the existing longitudinal magnetic field mode; Figure 10 This is a schematic diagram of the existing diameter rotating magnetic field mode. Detailed Implementation

[0020] The following describes embodiments of the present invention. However, it should be understood that the disclosed embodiments are merely examples, and other embodiments may take various alternative forms.

[0021] Furthermore, it should be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or apparatus that comprises a list of elements may include not only those elements but also elements not expressly listed or inherent to such process, method, article, or apparatus.

[0022] First, some technical terms and working principles involved in this application will be explained. In this invention, the electromagnet is a magnetic core wound with an excitation coil, which generates a magnetic field when an electric current is passed through it. The Lorentz force is the force exerted on a moving charge in a magnetic field, and its direction follows the right-hand rule, with the formula F=J×B, where J is the current density vector (i.e., the direction of the current in the arc), and B is the magnetic induction intensity vector. The welding arc itself can be regarded as a flexible current-carrying conductor, and its current direction is roughly along the welding torch axis. Therefore, a ring-shaped self-generated magnetic field is generated around the arc. When the external magnetic field interacts with the self-generated magnetic field of the arc, it changes the force balance in the arc plasma, thereby achieving the control of the arc shape and trajectory. This invention uses multiple electromagnets arranged around the welding torch to apply specific time-sequential excitation currents, generating a magnetic field with a predetermined spatial distribution and temporal variation law, so as to precisely control the arc.

[0023] One or more embodiments of the present invention will now be described with reference to the accompanying drawings.

[0024] In a first aspect, this invention provides an embodiment of an arc control method based on a rotating magnetic field. For example... Figure 1 The flowchart shown illustrates an arc control method based on a rotating magnetic field, comprising: S1. 2N electromagnets are evenly arranged around the welding torch, where N is an integer ≥2.

[0025] In one specific embodiment, the present invention provides an arc control method based on a rotating magnetic field and an arc control system based on a rotating magnetic field. The system includes 2N (N is an integer ≥2) electromagnets uniformly arranged circumferentially along the welding torch, a multi-channel excitation power supply, and a magnetically controlled arc controller. These 2N electromagnets form a closed-loop ring array. For example... Figure 2 In the welding torch, 12 electromagnets of the same specification are evenly arranged around the circumference of the torch, and are installed at equal intervals of 30° around the insulation of the torch. Figure 3 As shown, this is a top view of the electric arc under force without any external magnetic field. These 12 electromagnets can be labeled as (1) to (12) respectively, forming a structure similar to the stator of a torque motor, providing a hardware basis for generating various complex magnetic fields.

[0026] S2. Select the current working mode according to the control target of electric arc energy.

[0027] As a feasible implementation, when it is necessary to increase the concentration of arc energy, the first mode, namely the chord rotating magnetic field mode, is selected. In the first mode, the controller controls multiple excitation power supplies to sequentially excite adjacent pairs of electromagnets on a periodic basis; here, "adjacent" refers to electromagnets that are mechanically adjacent on the circumference. When it is necessary to regulate the arc energy distribution, such as regulating the heat flow distribution of the molten pool or improving weld formation, the second mode, namely the sharp-angle rotating magnetic field mode, is selected. The above-mentioned automatic selection of the working mode based on the target of arc energy regulation achieves adaptive optimization for different welding conditions, ensuring that the arc always works in the best state, and significantly improving the adaptability of the welding process and the yield.

[0028] S3. In response to the need to increase the concentration of electric arc energy, the first mode is selected and adjacent electromagnet pairs are excited sequentially according to the cycle. Currents in opposite directions are passed through the electromagnet pairs to generate a periodic unilateral Lorentz force pointing towards the welding torch axis on the electric arc plasma, thereby realizing continuous unilateral compression and circumferential rotation drive of the electric arc.

[0029] The first mode generates a periodic, unilateral Lorentz force pointing towards the welding torch axis on the arc plasma by sequentially exciting adjacent pairs of electromagnets and passing them in opposite directions. This achieves continuous unilateral compression and high-frequency circumferential rotation of the arc, significantly improving the energy concentration of the arc. Because the first mode uses a high-frequency, circumferential, unilateral Lorentz force pointing towards the axis to continuously compress and rotate the circular arc, it concentrates the arc energy towards the center, significantly improving the rigid energy density of the arc. Therefore, it is suitable for applications requiring increased arc energy concentration.

[0030] S4. In response to the need to regulate the energy distribution of the electric arc, the second mode is selected and multiple sets of spatially symmetrically distributed electromagnet pairs are excited simultaneously to form a multi-lobed symmetrical magnetic field to apply radially symmetrical compressive force to the electric arc. By periodically rotating the excitation groups, the compression direction is rotated circumferentially.

[0031] The second mode generates a rotating, multi-lobed symmetrical magnetic field by synchronously exciting multiple sets of spatially symmetrically distributed electromagnets and periodically rotating the excitation groups. This dynamically changes the direction of the major axis of the elliptical arc, thereby actively regulating the heat flow distribution of the molten pool. Meanwhile, research shows that after applying a sharp-angled magnetic field, the cross-sectional area of ​​the elliptical arc is reduced compared to that of a circular arc. Therefore, this mode not only regulates the energy distribution but also compresses the arc, making it suitable for conditions where the arc energy distribution needs to be controlled, such as welding scenarios that require improved weld formation and control of molten pool flow.

[0032] The above-mentioned arc control method based on rotating magnetic field achieves high-precision adaptive control of arc shape and energy distribution through multi-mode electromagnetic excitation and automatic selection of working mode under different working conditions, which significantly improves the stability of the welding process and the quality of weld formation.

[0033] In some embodiments, the two electromagnets in the electromagnet pair excited in the first mode are spaced 90° apart on the circumference. For example... Figure 4 As shown, taking a system with 12 electromagnets as an example, the mechanical angle between adjacent electromagnets is 30°. Therefore, 90° corresponds to electromagnets spaced 3 positions apart in terms of mechanical angle. That is, the excited electromagnet pairs are (1,4)——(2,5)——(3,6)——(4,7)——(5,8)——(6,9)——(7,10)——(8,11)——(9,12)——(10,1)——(11,2)——(12,3). Setting the interval angle of the excited electromagnet pairs on the circumference in the first mode to 90° allows the local asymmetric magnetic field and the arc's self-generated magnetic field to interact optimally, thereby generating a maximized Lorentz force pointing towards the axis on one side of the arc, achieving efficient unilateral compression. If the interval angle is too small, the magnetic field superposition area will be too narrow, resulting in insufficient compression effect; if the interval angle is too large, it may weaken the local asymmetric characteristics of the magnetic field, affecting the directionality of unilateral compression.

[0034] In some embodiments, the switching angle of the excited electromagnet pair in the first mode and the second mode is 360° / (2N). For example, as Figure 4 As shown, for a system with 12 electromagnets (N=6), the switching angle is 360° / 12=30°, meaning that each time the electromagnet pair is switched, the excited pair rotates 30° circumferentially. This switching angle is directly related to the total number of electromagnets, ensuring that each pair is excited once within a complete cycle (360°), thus achieving uniform and continuous circumferential compression of the arc. Specifically, when switching from the excitation pair (1,4) to (2,5), the compression position moves 30° circumferentially; when switching to (3,6), it moves another 30°, and so on. After 12 switching cycles, a complete rotation cycle is completed.

[0035] According to several embodiments of the present invention, adjacent pairs of electromagnets are excited sequentially in a periodic manner, including: exciting only one pair of electromagnets in each excitation period, and rotating the excited electromagnets in turn between different excitation periods, so that the unilateral compression position moves sequentially in the circumferential direction.

[0036] In some embodiments, such as Figure 4As shown, for a system with 12 electromagnets, the total number of excitation periods within a cycle T is related to the number of electromagnets moving uniformly along the circumference of the welding torch. In this embodiment, a total of 12 electromagnets are arranged, therefore, there are 12 excitation periods within a cycle, t1~t12, and the duration of each excitation period is equal. The excitation sequence within a cycle is: (1,4)——(2,5)——(3,6)——(4,7)——(5,8)——(6,9)——(7,10)——(8,11)——(9,12)——(10,1)——(11,2)——(12,3).

[0037] During the first excitation period t1, only electromagnets (1, 4) are energized, and the currents are in opposite directions. A forward current flows through electromagnet (1), and a reverse current flows through electromagnet (4), forming a locally asymmetrical N / S polarity pair. This local magnetic field interacts with the ring-shaped self-generated magnetic field of the arc, generating a Lorentz force pointing towards the welding torch axis on the side closer to electromagnets (1) and (4), thus compressing the arc on one side. The switching angle between adjacent excitation pairs is 360° / (2N) = 30°. The frequency of the excitation current determines the compression and rotation speed, which can be adjusted within the range of 1Hz to 500Hz.

[0038] During the second excitation period t2, the next pair of adjacent electromagnets (2, 5) is switched. A positive current is passed through electromagnet (2) and a reverse current is passed through electromagnet (5), forming a locally asymmetrical NS polarity pair. At this time, the position of the single-sided compression is also rotated by 30°.

[0039] This cycle continues until the 12th excitation period t12, when switching to the next pair of adjacent electromagnets (12, 3), a positive current is passed through electromagnet (12) and a reverse current is passed through electromagnet (3), forming a locally asymmetrical NS polarity pair.

[0040] In the first excitation period t1, the adjacent electromagnet pair (1, 4) generates a local asymmetric magnetic field. Under the influence of this magnetic field, the arc region closer to the electromagnet is enhanced because the applied magnetic field and the arc's self-generated magnetic field are in the same direction, while the magnetic field distribution on the side farther from the electromagnet is sparser, having less impact on the arc. This generates a Lorentz force F pointing towards the welding torch axis on the enhanced side, causing unilateral compression of the arc. Before the arc returns to its circular state, the second excitation period t2 quickly begins, and the newly activated electromagnet pair (2, 5) generates radial thrust on the other side, further compressing the arc. After 12 cycles of switching, the electromagnet group completes continuous unilateral compression and circumferential rotation of the arc. By adjusting the frequency of the excitation current, the frequency of the arc's periodic contraction and expansion can be effectively controlled, thereby achieving precise control of the arc's dynamic behavior.

[0041] According to several embodiments of the present invention, adjacent pairs of electromagnets are excited sequentially in a periodic manner, including: simultaneously exciting multiple sets of adjacent pairs of electromagnets in each excitation period, and cyclically rotating the excited electromagnet combinations between different excitation periods, so that multiple sets of compression positions rotate synchronously in the circumferential direction.

[0042] As a feasible embodiment, adjacent pairs of electromagnets are excited sequentially in a periodic manner, including simultaneously exciting multiple sets of adjacent pairs of electromagnets within each excitation period. The total number of excitation periods within a period T is related to the number of electromagnets uniformly arranged along the circumference of the welding torch. In this embodiment, a total of 12 electromagnets are arranged, therefore, there are 12 excitation periods within one period, t1~t12, and each excitation period has an equal duration. Figure 5 As shown, the excitation sequence within one cycle is: (1,4) and (2,5) — (2,5) and (3,6) — (3,6) and (4,7) — (4,7) and (5,8) — (5,8) and (6,9) — (6,9) and (7,10) — (7,10) and (8,11) — (8,11) and (9,12) — (9,12) and (10,1) — (10,1) and (11,2) — (11,2) and (12,3) — (12,3) and (1,4).

[0043] During the first excitation period t1, two adjacent electromagnetic pairs (1, 4) and (2, 5) are simultaneously excited, and positive current is passed through electromagnets (1) and (2), and reverse current is passed through electromagnets (4) and (5), forming two adjacent local asymmetric magnetic field regions, and generating two forces pointing towards the axis, which synchronously compress the electric arc at two positions.

[0044] During the second excitation period t2, the excitation combination is changed to (2, 5) and (3, 6), and forward current is passed through electromagnets (2) and (3), and reverse current is passed through electromagnets (5) and (6).

[0045] This cycle continues, and in the 12th excitation period t12, the excitation combination is changed to (12, 3) and (1, 4), and a forward current is passed through electromagnets (12) and (1), while a reverse current is passed through electromagnets (3) and (4).

[0046] The simultaneous excitation of two adjacent pairs of electromagnets creates a stronger local magnetic field compared to exciting only a single pair. This allows for the synchronous circumferential rotation of multiple compression positions, forming a more complex compression force field and enabling more precise control of the electric arc. For example, in the first excitation period t1, the resultant force generated by exciting only a single pair of electromagnets (1) and (4) is approximately 45°, while the resultant force generated by simultaneously exciting two adjacent pairs of electromagnets (1, 4) and (2, 5) is approximately 60°. By combining these two excitation modes, a fine-tuned force direction control with a 15° angle difference can be achieved, thus enabling more precise compression and rotation control of the electric arc.

[0047] According to several embodiments of the present invention, synchronously exciting multiple sets of spatially symmetrically distributed electromagnet pairs includes: synchronously exciting multiple sets of electromagnet pairs that are mirror- or rotationally symmetrically distributed on a circumference, each set of electromagnet pairs containing at least two electromagnets to form a multi-lobed symmetrical magnetic field.

[0048] In some embodiments, in the second mode, multiple pairs of electromagnets symmetrically distributed in space are synchronously excited to form a multi-lobed symmetrical magnetic field. The total number of excitation periods within a cycle T is related to the number of electromagnets uniformly arranged along the circumference of the welding torch. In this embodiment, a total of 12 electromagnets are arranged, therefore, there are 12 excitation periods within one cycle, t1~t12, and each excitation period has an equal duration. Figure 6 As shown, in a system of 12 electromagnets, the excitation sequence within one cycle is as follows: (1,3) and (7,9) — (2,4) and (8,10) — (3,5) and (9,11) — (4,6) and (10,12) — (5,7) and (11,1) — (6,8) and (12,2) — (7,9) and (1,3) — (8,10) and (2,4) — (9,11) and (3,5) — (10,12) and (4,6) — (11,1) and (5,7) — (12,2) and (6,8).

[0049] During the first excitation period t1, two pairs of electromagnets (1,3) and (7,9) that are symmetrically distributed in space are synchronously excited, and positive current is passed through electromagnets (1) and (7), while reverse current is passed through electromagnets (3) and (9). At this time, the two sets of magnetic poles work together to generate a two-lobed symmetrical enhanced magnetic field around the arc, which applies a radially symmetrical compressive force pointing towards the axis of the arc, making the arc cross-section present an approximately elliptical shape.

[0050] During the second excitation period t2, the excitation groups are alternated between (2, 4) and (8, 10), and positive current is applied to electromagnets (2) and (8), while reverse current is applied to electromagnets (4) and (10). This causes the direction of the radial compressive force (i.e., the direction of the major axis of the ellipse) to rotate 30° circumferentially.

[0051] This cycle repeats until the 12th excitation period t12, when the excitation groups are switched between electromagnet pairs (12, 2) and (6, 8), and forward current is applied to electromagnets (12) and (6), while reverse current is applied to electromagnets (2) and (8). The duration of each of the above excitation periods is equal, and the total period T is adjustable (corresponding to the frequency f = 1 / T).

[0052] In the first excitation period t1, the two synchronously excited spatially symmetrical electromagnet pairs (1,3) and (7,9) form NS polarity pairs, i.e., electromagnet pair (1,3) forms an NS polarity pair, and electromagnet pair (7,9) forms an NS polarity pair. The magnetic field generated is basically consistent with the direction of the arc's self-generated magnetic field, which enhances the magnetic field strength around the arc, thereby applying a symmetrical radial compressive force to the arc. In the second excitation period t2, the excitation groups are switched to (2,4) and (8,10), which also generate radial compressive forces of equal magnitude but with a 30° deflection in direction. After 12 rapid rotations of excitation, the electromagnet groups complete the full circumferential compression of the arc. By dynamically and periodically adjusting the direction of the radial compressive force (i.e., the direction of the major axis of the arc's elliptical cross section), the heat transfer direction of the arc to the molten pool and the distribution of the molten pool flow field can be effectively controlled.

[0053] like Figure 7 A schematic diagram of an existing fixed-angle magnetic field mode is shown, which uses multiple pairs of electromagnets arranged with alternating polarities to form an elliptical or petal-shaped arc. While it can exert a certain degree of compression on the arc, this compression is symmetrical and relatively static, and the direction of the resulting radial compressive force is fixed. This limits the ability to finely control the local dynamic response of the arc, making it difficult to meet the real-time optimization requirements for arc energy distribution under complex welding conditions, such as those requiring arc energy regulation. Figure 6 As shown, the second mode provided by the present invention improves the existing static radial compression of the sharp-angle magnetic field to dynamic rotational compression. By periodically changing the excitation group, the compression direction is continuously changed along the circumference, dynamically changing the major axis direction of the elliptical electric arc, thereby actively controlling the heat flow distribution of the molten pool, significantly improving the weld formation quality and expanding the process adaptability.

[0054] As a feasible embodiment, multiple sets of spatially symmetrically distributed electromagnet pairs under synchronous excitation can be mirror- or rotationally symmetrically distributed on the circumference. Each set of electromagnet pairs can contain two or more electromagnets, thereby forming a two-lobed, three-lobed or multi-lobed compressive force field.

[0055] According to several embodiments of the present invention, the arc control method based on a rotating magnetic field further includes: dynamically switching between a first mode and a second mode according to at least one of welding current, arc voltage, welding speed, visual signal of molten pool or arc sensing signal, and adjusting the amplitude, frequency and phase of the excitation current.

[0056] According to several embodiments of the present invention, adjusting the amplitude, frequency and phase of the excitation current includes: judging the arc stability based on the arc voltage fluctuation rate; if the arc voltage fluctuation rate exceeds a first preset threshold, increasing the frequency and amplitude of the excitation current until the arc voltage fluctuation rate falls back to below a second preset threshold.

[0057] As a specific implementation, the stability of the arc is determined by real-time monitoring of the arc voltage and calculation of its fluctuation rate. A first preset threshold is set at 10%, and a second preset threshold at 5%. When the calculated arc voltage fluctuation rate exceeds 10%, the arc is deemed unstable. At this point, if the system is currently operating in the first mode, the string rotation frequency will be automatically increased, for example, from 100Hz to 200Hz, and the excitation current amplitude will be increased, for example, by 15%, to enhance the constraint and drive of the arc, thereby suppressing fluctuations. During this process, the arc voltage fluctuation rate is continuously monitored until it falls below 5%, at which point the arc is considered to have stabilized.

[0058] The aforementioned arc control method based on a rotating magnetic field achieves high-precision adaptive control of arc morphology and energy distribution by combining multi-mode electromagnetic excitation with intelligent control, significantly improving the stability of the welding process and the quality of weld formation.

[0059] A second aspect of the invention provides an embodiment of an arc control system based on a rotating magnetic field. Further reference... Figure 2 An arc control system based on a rotating magnetic field, used to achieve any of the aforementioned methods, includes: 2N electromagnets uniformly arranged along the circumference of a welding torch, where N is an integer ≥2; multiple independently controllable excitation power supplies, each connected to an electromagnet; and a magnetically controlled arc controller, used to select the current operating mode according to the arc energy control target and control the excitation power supply to apply excitation current to the electromagnets; wherein, in response to the need to increase the arc energy concentration, a first mode is selected, and the magnetically controlled arc controller controls the excitation power supply to periodically excite adjacent pairs of electromagnets sequentially, and applies currents in opposite directions to the electromagnet pairs to generate a periodic unilateral Lorentz force pointing towards the welding torch axis on the arc plasma, thereby achieving continuous unilateral compression and circumferential rotation drive of the arc; in response to the need to control the arc energy distribution, a second mode is selected, and the magnetically controlled arc controller controls the excitation power supply to synchronously excite multiple sets of spatially symmetrically distributed pairs of electromagnets to form a multi-lobed symmetrical magnetic field to apply a radially symmetrical compressive force to the arc, and by periodically rotating the excitation groups, the compression direction is rotated circumferentially.

[0060] As one specific embodiment, such as Figure 2 As shown, 12 electromagnets are evenly arranged around the welding torch, labeled as electromagnets (1) to (12). Each electromagnet is independently connected to a multi-channel controllable excitation power supply. This excitation power supply can provide each electromagnet with an independently adjustable current in terms of amplitude, frequency, and phase according to the received instructions. The frequency range of the excitation current of the excitation power supply is 1~500Hz. The magnetic arc controller can be one of a single-chip microcomputer, digital signal processor, ARM processor, field-programmable gate array, programmable logic controller, or industrial computer. The magnetic arc controller integrates or runs a pattern recognition module and parameter optimization algorithm to receive real-time welding parameters (such as welding current, arc voltage, welding speed) or sensor feedback signals (such as molten pool visual sensor images, arc sensing signals), and automatically selects the current best working mode according to the preset logic or algorithm, and generates the corresponding excitation timing signal, which is sent to the multi-channel excitation power supply for execution.

[0061] The aforementioned arc control system based on a rotating magnetic field achieves high-precision adaptive control of arc morphology and energy distribution through a combination of multi-mode electromagnetic excitation and intelligent control, significantly improving the stability of the welding process and the quality of weld formation.

[0062] In addition, the arc control system based on rotating magnetic field of the present invention also supports a variety of existing magnetic field modes.

[0063] In some embodiments, the arc control system based on a rotating magnetic field of the present invention supports a transverse magnetic field mode. For example... Figure 8 As shown, when it is necessary to increase the penetration depth, the controller can select this mode to excite only a pair of electromagnets arranged in a diametrical manner, such as (1, 7), and pass an alternating current through them, thereby generating an alternating magnetic field perpendicular to the welding direction, driving the arc to oscillate back and forth in the welding direction.

[0064] In some embodiments, the arc control system based on a rotating magnetic field of the present invention supports a longitudinal magnetic field mode. For example... Figure 9 As shown, when it is necessary to widen the weld, the controller can select this mode to excite only another pair of electromagnets arranged in opposite directions, such as (4, 10), and pass an alternating current through them, thereby generating an alternating magnetic field parallel to the welding direction, driving the arc to oscillate back and forth in a direction perpendicular to the welding direction (i.e., transverse).

[0065] In some embodiments, the arc control system based on a rotating magnetic field of the present invention supports a diameter rotating magnetic field mode. For example... Figure 10As shown, when it is necessary to stir the molten pool and improve the uniformity of the structure, the controller can select this mode to excite each pair of electromagnets arranged in opposite directions in a cycle, such as (1,7)——(2,8)——(3,9)——(4,10)——(5,11)——(6,12), forming a magnetic field that rotates symmetrically around the welding gun axis, driving the entire arc to rotate.

[0066] Finally, it should be noted that those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The program for setting system parameters can be stored in a computer-readable storage medium. When executed, the program can include the processes of the embodiments of the above methods. The storage medium for the program can be a magnetic disk, optical disk, read-only memory (ROM), or random access memory (RAM), etc. The above computer program embodiments can achieve the same or similar effects as any of the corresponding foregoing method embodiments.

[0067] Furthermore, the method disclosed in the embodiments of the present invention can also be implemented as a computer program executed by a processor, which may be stored in a computer-readable storage medium. When the computer program is executed by the processor, it performs the functions defined in the method disclosed in the embodiments of the present invention.

[0068] Furthermore, the above-described method steps and system units can also be implemented using a controller and a computer-readable storage medium for storing a computer program that enables the controller to perform the functions of the above-described steps or units.

[0069] Those skilled in the art will also understand that the various exemplary logic blocks, modules, circuits, and algorithm steps described in conjunction with the disclosure herein can be implemented as electronic hardware, computer software, or a combination of both. To clearly illustrate this interchangeability between hardware and software, the functionality of various illustrative components, blocks, modules, circuits, and steps has been generally described. Whether this functionality is implemented as software or as hardware depends on the specific application and the design constraints imposed on the system as a whole. Those skilled in the art can implement the functionality in various ways for each specific application, but such implementation decisions should not be construed as departing from the scope of the embodiments disclosed herein.

[0070] The above are exemplary embodiments disclosed in this invention. However, it should be noted that various changes and modifications can be made without departing from the scope of the embodiments of this invention as defined by the claims. The functions, steps, and / or actions of the methods according to the disclosed embodiments described herein do not need to be performed in any particular order. Furthermore, although the elements disclosed in the embodiments of this invention may be described or claimed individually, they may be understood as multiple unless explicitly limited to a singular number.

[0071] It should be understood that, as used herein, the singular form “a” is intended to include the plural form as well, unless the context clearly supports an exception. It should also be understood that, as used herein, “and / or” refers to any and all possible combinations of one or more of the associated listed items.

[0072] The embodiment numbers disclosed in the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0073] Those skilled in the art will understand that all or part of the steps of the above embodiments can be implemented by hardware or by a program instructing related hardware. The program can be stored in a computer-readable storage medium, such as a read-only memory, a disk, or an optical disk.

[0074] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the invention (including the claims) is limited to these examples. Within the framework of the invention, technical features of the above embodiments or different embodiments can be combined, and many other variations of different aspects of the invention exist, which are not provided in the details for the sake of brevity. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the invention should be included within the protection scope of the invention.

Claims

1. An arc control method based on a rotating magnetic field, characterized in that, include: 2N electromagnets are evenly arranged around the welding torch, where N is an integer ≥ 2; Select the current operating mode based on the target of controlling the electric arc energy; In response to the need to increase the concentration of arc energy, a first mode is selected and adjacent electromagnet pairs are sequentially excited periodically. Currents in opposite directions are then applied to these electromagnet pairs to generate a periodic, unilateral Lorentz force pointing towards the welding torch axis on the arc plasma, thereby achieving continuous unilateral compression and circumferential rotation of the arc. In the first mode, the two electromagnets in the excited electromagnet pair are spaced 90° apart on the circumference. In the first mode, the switching angle of the excited electromagnet pair is 360° / (2N). The sequential excitation of adjacent electromagnet pairs according to a period includes: Only one pair of electromagnets is excited during each excitation period, and the excited electromagnet pairs are rotated sequentially between different excitation periods, causing the unilateral compression position to move sequentially along the circumferential direction; or Multiple pairs of adjacent electromagnets are excited simultaneously during each excitation period, and the excited electromagnet combinations are rotated cyclically between different excitation periods, so that multiple compression positions rotate synchronously in the circumferential direction.

2. An arc control system based on a rotating magnetic field, characterized in that, The method for implementing the arc control method based on a rotating magnetic field as described in claim 1 includes: 2N electromagnets are evenly arranged around the circumference of the welding torch, where N is an integer ≥ 2; Multiple independently controllable excitation power supplies are connected to each of the electromagnets; A magnetically controlled arc controller is used to select the current working mode according to the target of arc energy regulation and to control the excitation power supply to apply excitation current to the electromagnet. In response to the need to increase the concentration of arc energy, the first mode is selected. The magnetic arc controller controls the excitation power supply to excite adjacent electromagnet pairs in a periodic manner and applies currents in opposite directions to the electromagnet pairs to generate a periodic unilateral Lorentz force pointing towards the welding torch axis on the arc plasma, thereby realizing continuous unilateral compression and circumferential rotation drive of the arc. In the first mode, the two electromagnets in the excited electromagnet pair are spaced 90° apart on the circumference. In the first mode, the switching angle of the excited electromagnet pair is 360° / (2N). The sequential excitation of adjacent electromagnet pairs according to a period includes: Only one pair of electromagnets is excited during each excitation period, and the excited electromagnet pairs are rotated sequentially between different excitation periods, causing the unilateral compression position to move sequentially along the circumferential direction; or Multiple pairs of adjacent electromagnets are excited simultaneously during each excitation period, and the excited electromagnet combinations are rotated cyclically between different excitation periods, so that multiple compression positions rotate synchronously in the circumferential direction.

3. The arc control system based on a rotating magnetic field according to claim 2, characterized in that, The frequency range of the excitation current of the excitation power supply is 1~500Hz.

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