Ultrahigh-voltage excitation variable-pulse-energy electric arc machining system, method and machine tool

Abstract

The invention relates to an ultrahigh-voltage excitation variable pulse energy arc machining system and method and a machine tool. The ultrahigh-voltage excitation variable pulse energy arc machining system comprises an arc power supply circuit, the arc power supply circuit is sequentially connected with a first power source and a first diode in series, the arc power supply circuit is further provided with a first switch part in series, and the ultrahigh-voltage excitation variable pulse energy arc machining system further comprises a dielectric breakdown circuit; a second power supply, a second switch piece and a second diode are sequentially connected to the dielectric breakdown circuit in series, the arc power supply circuit and the workpiece dielectric breakdown circuit are connected in parallel and then connected into a power supply loop, and the power supply loop is used for connecting a machine tool electrode and a workpiece; the output voltage of the second power source is larger than the output voltage of the first power source, when the second switch piece controls the medium breakdown circuit to be connected into the power supply loop, the current capable of being output by the second power source can break down the workpiece medium, and the machining efficiency and the machining quality are improved through the machining system.

Description

Technical Field

[0001] The present invention relates to the technical field of electro - machining, and particularly relates to an ultra - high - voltage excitation variable - pulse - energy arc - machining system, method and machine tool. Background Art

[0002] The statements herein only provide background art related to the present invention and do not necessarily constitute prior art.

[0003] In recent years, the aerospace industry has developed rapidly. To meet the service requirements of components in extreme environments, higher requirements are put forward for material properties. High - performance materials such as titanium alloys, nickel - based superalloys and composite materials have been widely used in the manufacturing of aero - engines, rocket engines and other high - end equipment due to their excellent strength, heat resistance and wear resistance. However, these materials are usually difficult - to - machine materials, and problems such as severe tool wear, large machining deformation and low removal efficiency are prone to occur during the machining process, posing great challenges to precision manufacturing.

[0004] In the field of mechanical machining, arc - machining is a new type of non - traditional machining method that has emerged in recent years. It uses a long - pulse high - energy - density quasi - steady - state plasma to rapidly melt and vaporize materials to achieve high - speed removal of materials. Its greatest feature is high machining efficiency and low machining accuracy.

[0005] Patent CN105081525B discloses an arc - machining discharge - state detection system. During operation, arc - machining is carried out by the action of an arc - machining power supply EAMDC. However, when the above - mentioned arc - machining discharge system operates, there is only one low - voltage arc - machining power supply, which has a delay during dielectric breakdown, a low success rate, is only applicable to metals with good conductivity, has a weak breakdown ability for heterogeneous or composite materials, and it is difficult to discharge the electro - erosion products in time, resulting in low arc - machining efficiency and low machining accuracy. Summary of the Invention

[0006] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide an ultra - high - voltage excitation variable - pulse - energy arc - machining system, method and machine tool, which improve the efficiency and machining accuracy of arc - machining.

[0007] To achieve the above purpose, the present invention is realized through the following technical solutions:

[0008] In the first aspect, an embodiment of the present invention provides an ultra - high - voltage excitation variable - pulse - energy arc - machining system, including an arc power - supply circuit. A first power supply and a first diode are sequentially connected in series on the arc power - supply circuit. A first switching element is also connected in series on the arc power - supply circuit. It further includes a dielectric - breakdown circuit. A second power supply, a second switching element and a second diode are sequentially connected in series on the dielectric - breakdown circuit. The arc power - supply circuit and the workpiece dielectric - breakdown circuit are connected in parallel and then connected into a power - supply loop, and the power - supply loop is used to connect the machine - tool electrode and the workpiece;

[0009] The output voltage of the second power supply is greater than that of the first power supply. When the second switching device controls the dielectric breakdown circuit to be connected to the power supply circuit, the current output by the second power supply can break down the workpiece dielectric.

[0010] Optionally, the output voltage of the second power supply is 900V - 1100V, preferably 1000V, and the output voltage of the first power supply is 75V - 85V, preferably 80V.

[0011] Optionally, the first switching device uses a first IGBT tube, and the first IGBT tube is connected to the first pulse generator.

[0012] Optionally, the first pulse generator can enable the arc power supply circuit to generate a pulsed current with a pulse width of 0 - 1000 milliseconds and a frequency of 4 - 6Hz through the first IGBT tube.

[0013] Optionally, the second switching device uses a second IGBT tube, and the second IGBT tube is connected to the second pulse generator.

[0014] Optionally, the second pulse generator can enable the dielectric breakdown circuit to generate a pulsed current with a pulse width of 1 microsecond to 10 microseconds and a frequency of 45Hz - 55Hz through the second IGBT tube.

[0015] Optionally, it further includes an independent detection circuit for connecting the workpiece and the machine tool electrode. A third power supply, a fixed-value resistor, a Hall sensor, and a third diode are sequentially connected in series on the independent detection circuit.

[0016] Optionally, one end of the Hall sensor is grounded, and the other end is used as the output end of the independent detection circuit and is connected to the input end of the voltage stabilization circuit. The output end of the voltage stabilization circuit is connected to the positive terminal port of the voltage comparator in the voltage comparison circuit, and the output end of the voltage comparison circuit is connected to the controller.

[0017] In a second aspect, an embodiment of the present invention provides a working method for a super-high voltage excitation variable pulse energy arc machining system:

[0018] The second switching device controls the dielectric breakdown circuit to conduct, and the second power supply outputs current to break down the workpiece dielectric and form a stable discharge channel.

[0019] After the second switching device is disconnected, the first switching device conducts the arc power supply circuit, and the second power supply outputs current to perform arc machining on the workpiece.

[0020] In a third aspect, an embodiment of the present invention provides a super-high voltage excitation variable pulse energy arc machining machine tool, which is provided with the super-high voltage excitation variable pulse energy arc machining system described in the first aspect.

[0021] The beneficial effects of the present invention are as follows:

[0022] 1. The arc machining system of the present invention is provided with a dielectric breakdown circuit. After the dielectric breakdown circuit is turned on through the second switching element, it can use the second power supply to provide a high-voltage current to break down the workpiece dielectric, thereby increasing the discharge gap under the action of high-voltage excitation, and can cooperate with the high-pressure pump to flush liquid to achieve efficient chip removal and cooling, improve the discharge environment, facilitate the discharge of electrolytic products, improve the utilization rate of effective arcs, and further can greatly improve the arc machining efficiency, reaching dozens or even hundreds of times that of traditional electrical discharge machining. Moreover, by using the high-voltage current provided by the second power supply to break down the workpiece dielectric, the high-voltage pulse energy is concentrated, and a stable plasma channel is directly formed, which can avoid multiple attempts to break down or failure caused by uneven local impedance of the material during low-voltage breakdown. The high-voltage current provided by the second power supply to break down the workpiece dielectric can reduce local energy accumulation, the channel shape is regular, reduce microcracks and heat-affected zones on the machining surface, improve the machining quality. In addition, by using the high-voltage breakdown of the workpiece dielectric by the second power supply, it has a strong breakdown ability for heterogeneous or composite materials, is suitable for arc machining of heterogeneous or composite materials, improves the applicability of the entire machining system. When the second power supply works, it directly breaks down the oxide layer or protective coating on the workpiece surface without pretreatment (such as pickling, grinding), saving processes.

[0023] 2. The arc machining system of the present invention can output pulsed discharges through the first pulse generator, the second pulse generator, the first IGBT tube, and the second IGBT tube. The pulse width can be accurately controlled through the first pulse generator and the second pulse generator, and then the arc discharge energy can be controlled, so as to realize roughing and finishing integration machining. Especially under the ultra-high-voltage excitation of the dielectric breakdown circuit, high-precision control can be achieved while high-efficiency machining, breaking through the bottleneck of low precision in traditional arc machining.

[0024] 3. The arc machining system of the present invention realizes the integrated application of high-voltage short pulses and low-voltage long pulses through the composite design of the dielectric breakdown circuit and the arc power supply circuit, making the arc discharge process more stable and the electrolytic products easier to discharge, thereby improving the machining efficiency and the machining surface quality. Description of the Drawings

[0025] The specification drawings forming a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention.

[0026] Figure 1 is the overall schematic diagram of Embodiment 1 of the present invention;

[0027] Figure 2 is the method flow chart of Embodiment 2 of the present invention;

[0028] Figure 3 It is a schematic diagram of pulse discharge voltage and discharge current;

[0029] Among them, 1. The first IGBT tube, 2. The first diode, 3. The second diode, 4. The second IGBT tube, 5. The water tank, 6. The water pump, 7. The X-direction drive system, 8. The Y-direction drive system, 9. The Z-direction drive system. Specific implementation mode

[0030] Electrical Arc Machining (EAM) is a new type of special machining method that uses the local high temperature generated by the arc discharge between the tool electrode and the workpiece electrode to erode the workpiece material, so as to meet the predetermined machining requirements of the workpiece size accuracy, shape and position accuracy, and surface quality. As a new type of electric machining technology, electrical arc machining inherits the advantages of electrical discharge machining. During the machining process, the tool electrode does not directly contact the workpiece, and there is no macroscopic acting force. It only relies on the plasma between the tool electrode and the workpiece to erode the material, but the energy density of its plasma can reach 1010 J / cm 2 , and the temperature can reach tens of thousands of degrees, much higher than the temperature of the electrical discharge machining plasma. Taking the arc plasma as the energy source, the workpiece material can be efficiently melted and vaporized, and the material removal rate can reach 20000 mm 3 / min, which has unique advantages in machining difficult-to-cut materials such as high strength, high hardness, high wear resistance, and high heat resistance, and is especially suitable for the machining of parts such as aerospace impeller disks, rocket engine inducer wheels, compressor casings, and aluminum matrix silicon carbide brackets made of materials such as titanium alloys, nickel-based alloys, and silicon aluminum alloys, and has broad application prospects in the high-precision and sophisticated fields of aerospace

[0031] Example 1

[0032] This embodiment provides a super-high-voltage excitation variable pulse energy electrical arc machining system, as Figure 1 shown, including an electrical arc machining power supply module (EAMPC), a voltage stabilizing module (RV), a voltage comparison module (VC), and an independent detection circuit module (IDC). The machining system of this embodiment is improved on the basis of the electrical arc machining discharge state detection system disclosed in Patent CN105081525B, and only the electrical arc machining power supply module is improved. The voltage stabilizing module, the voltage comparison module, and the independent detection circuit module can adopt the technologies disclosed in Patent CN105081525B.

[0033] In this embodiment, the arc machining power supply module includes a power supply circuit. The two ends of the power supply circuit are respectively used to connect the workpiece and the machine tool electrode. An arc power supply circuit and a dielectric breakdown circuit which are connected in parallel are connected in series in the power supply circuit. The arc power supply circuit can adopt the technology disclosed in CN105081525B. A first power supply P2 and a first diode 2 are connected in series on the arc power supply circuit. The first diode 2 is used to be connected to the machine tool electrode through the power supply circuit, and the negative electrode of the first power supply is used to be connected to the workpiece through the power supply circuit.

[0034] In this embodiment, the first power supply P2 is a DC power supply with an output voltage of 75V - 85V, preferably 80V.

[0035] In traditional technology, it is considered that only DC voltage can generate arc discharge, and pulse voltage can only generate pulse discharge. But in fact, arc discharge is not necessarily discharge under DC voltage. Usually, the so-called pulse spark discharge also contains arc discharge components. According to electrical engineering theory, the distinction between arc discharge and spark discharge lies in their different volt-ampere characteristics. The discharge with a positive volt-ampere characteristic (as the inter-electrode voltage decreases, the current passing through the medium decreases) is arc discharge, and the discharge with a negative volt-ampere characteristic (as the inter-electrode voltage decreases, the current passing through the medium increases) is spark discharge. DC voltage is difficult to control accurately in arc machining. Therefore, in this embodiment, pulse current is used for arc machining. Therefore, a first switching element is connected in series in the arc power supply circuit. The first switching element is used to control the conduction and disconnection of the arc power supply circuit so as to realize the first power supply outputting pulse current. The first switching element adopts a first IGBT tube 1. The first IGBT tube 1 is connected to a first pulse generator. The first pulse generator can control the frequency and pulse width of the pulse current of the arc power supply circuit through the first IGBT tube 1 to ensure the stability of arc discharge and machining accuracy.

[0036] Currently, arc machining is usually used for rough machining of large allowances of workpieces. Although the material removal rate has exceeded 20000mm 3 / min, which is dozens or even hundreds of times that of EDM, it has the disadvantages of low machining accuracy and poor machining surface quality, and cannot be competent for the task of machining such parts in one go, becoming a bottleneck restricting the development of this machining technology. In this embodiment, the arc power supply circuit outputs an 80V pulse voltage through the first IGBT tube 1 and the first pulse generator. The pulse width is adjustable, ranging from 0 to 1000 milliseconds, and is responsible for providing the main machining energy. The first pulse generator is connected to the control system and can adjust the pulse width and frequency in real time through the control system to adapt to different machining requirements to ensure the stability of arc discharge and machining accuracy.

[0037] Preferably, the first pulse generator can enable the arc power supply circuit to generate a pulsed current with a pulse width of 0 - 1000 milliseconds and a frequency of 4 - 6 Hz through the first IGBT tube 1.

[0038] The arc machining of the workpiece based on the adjustable pulsed current by the conduction of the arc power supply circuit breaks the reality that it is difficult to perform precision control in arc machining with a DC power supply, breaks through the traditional cognition, and brings the possibility of high-precision arc machining.

[0039] In this embodiment, on the basis of the existing arc machining power supply module, a dielectric breakdown circuit is added. The dielectric breakdown circuit is arranged in parallel with the arc power supply circuit and is connected to the power supply loop after being paralleled. A second power supply P1, a second switching element, and a second diode 3 are sequentially connected in series on the dielectric breakdown circuit. The second switching element enables a pulsed current to be generated in the dielectric breakdown circuit.

[0040] The second power supply P1 can output an ultra-high voltage. In this embodiment, the second power supply P1 uses a DC power supply that can output 900V - 1100V, preferably 1000V. The negative electrode of the second power supply P1 is used to connect to the workpiece through the power supply loop.

[0041] In this embodiment, the second switching element uses a second IGBT tube 4. The second IGBT tube 4 is connected to the second pulse generator. Through the second IGBT tube 4 and the second pulse generator, a high-voltage pulsed current can be generated in the dielectric breakdown circuit to break down the workpiece dielectric.

[0042] Preferably, the second pulse generator can enable the dielectric breakdown circuit to generate a pulsed current with a pulse width of 1 microsecond to 10 microseconds and a frequency of 45Hz - 55Hz through the second IGBT tube 4 for breaking down the workpiece dielectric.

[0043] The voltage stabilization module, the voltage comparison module, and the independent detection circuit module can adopt the technologies disclosed in Patent CN105081525B. The independent detection circuit module includes an independent detection circuit. A third power supply, a Hall sensor CS, a fixed-value resistor R1, and a third diode are sequentially connected in series on the independent detection circuit. The third power supply has a rated voltage of 55V, the fixed-value resistor R1 is 55Ω, the third electrode tube cooperates with the first diode and the second diode to isolate the independent detection circuit. One end of the Hall sensor CS is grounded, and the other end is used as the output end of the independent detection circuit and is connected to the input end of the voltage stabilization circuit.

[0044] The voltage stabilization module includes a voltage stabilization circuit, in which a fixed-value resistor R2, a fixed-value resistor R3 and a capacitor C1 are connected. The fixed-value resistor R2 is 5.7 kΩ, the fixed-value resistor R3 is 150 kΩ, and the capacitor is 68 nF. The input signal of the voltage stabilization circuit is the output signal Ui of the independent detection circuit. After voltage division, the output voltage is Us.

[0045] The voltage comparison module includes a voltage comparison circuit, which consists of a voltage comparator UC, a DC power supply VCC and a slide wire rheostat R4. The rated voltage of the DC power supply VCC is 5V. The output signal of the voltage stabilization circuit is the input signal of the voltage comparison circuit. The output terminal of the voltage stabilization circuit is connected to the positive terminal port of the voltage comparator UC. The output terminal of the voltage comparison circuit is connected to the input interface of the controller. In this embodiment, the PLC controller can be used as the controller.

[0046] The voltage stabilization module, the voltage comparison module and the independent detection circuit module can adopt the existing technology, and their further technical details will not be described in detail here.

[0047] The arc machining system of this embodiment only adds a dielectric breakdown circuit, a first pulse generator, a second pulse generator and a first IGBT tube. The rest of the structure is the same as the technology described in Patent CN105081525B, and will not be described in further detail here.

[0048] The machining system of this embodiment is provided with a dielectric breakdown circuit. After the dielectric breakdown circuit is turned on through the IGBT tube, it can use the second power supply to provide a high-voltage current of 1000V to break through the workpiece medium, thereby increasing the discharge gap under the action of high-voltage excitation, being able to cooperate with the high-pressure pump for liquid flushing to achieve efficient chip removal and cooling, improving the discharge environment, facilitating the discharge of electro-erosion products, improving the utilization rate of the effective arc, and further being able to greatly improve the arc machining efficiency, reaching dozens or even hundreds of times that of traditional electrical discharge machining. Moreover, by using the 1000V high-voltage current provided by the second power supply to break through the workpiece medium, the high-voltage pulse energy is concentrated, directly forming a stable plasma channel, which can avoid multiple attempts or failures of breakdown due to uneven local impedance of the material during low-voltage breakdown. The 1000V high-voltage current provided by the second power supply to break through the workpiece medium can reduce local energy accumulation, the channel shape is regular, reducing the micro-cracks and heat-affected zones on the machining surface, improving the machining quality. In addition, using the second power supply to break through the workpiece medium at high voltage has a strong breakdown ability for heterogeneous or composite materials, is suitable for arc machining of heterogeneous or composite materials, improving the applicability of the entire machining system. When the second power supply works, it directly breaks through the surface oxide layer or protective coating of the workpiece without pretreatment (such as pickling, grinding), saving processes.

[0049] Embodiment 2

[0050] This embodiment provides a working method for the ultra-high voltage excitation variable pulse energy arc machining system described in Embodiment 1, as follows: Figure 2 It includes the following steps:

[0051] Fix the workpiece to be machined on the workbench and load the machining parameters. First, the second pulse generator conducts the dielectric breakdown circuit through the second IGBT tube, and outputs a high-frequency pulse voltage of 1000V through the second power supply. The pulse width is 5 microseconds and the frequency is 50kHz, which is used for dielectric breakdown of the workpiece to form a plasma channel for arc discharge. After the second pulse generator controls the dielectric breakdown circuit to conduct for a set time, observe whether a stable arc is formed. If a stable arc is not formed, adjust the working parameters of the second pulse generator and discharge again until a stable arc is formed.

[0052] After a stable arc is formed, the first pulse generator conducts the arc power supply circuit through the first IGBT tube and outputs a low-frequency pulse voltage of 80V through the first power supply. The pulse width is 50 milliseconds and the frequency is 5Hz. The initial phases of the two pulse voltages are the same. Adjust the fluid flushing speed of the machine tool, detect the arc state. If an abnormality occurs, adjust the frequency and pulse width of the low-frequency pulse voltage through the first pulse generator, and adjust the fluid pressure and electrode rotation speed until the arc state is normal, and then start machining the workpiece. The high-energy arc acts on the surface of the workpiece, and high-efficiency removal is achieved by locally melting and eroding the material at high temperature. The machining control system of the machine tool controls the movement trajectory of the tool electrode to complete the milling machining of complex shapes until the machining is completed.

[0053] During the arc machining of this embodiment, it is detected in real time whether the discharge gap is blocked. If the discharge gap is blocked, a short circuit occurs, and the control system immediately issues an instruction. The machine tool spindle drives the tool electrode to retract until the short circuit is eliminated, and then the machine tool spindle drives the tool electrode to feed again to the machining position and continue the arc machining.

[0054] In this embodiment, it is possible to judge whether the discharge gap is blocked by the abnormal fluctuation of the current signal captured by the Hall sensor of the independent detection module and / or the decrease of the current signal and / or by the comparison result of the actual discharge voltage received by the voltage comparator and the preset voltage.

[0055] By adopting the machining system and machining method of this embodiment, a dielectric breakdown circuit is provided. After the dielectric breakdown circuit is conducted through the second IGBT tube, it can use the second power supply to provide high-voltage current to break down the workpiece dielectric, thereby increasing the discharge gap and improving the discharge state under the action of high-voltage excitation, and can greatly improve the arc machining efficiency, reaching dozens or even hundreds of times that of traditional electric discharge machining.

[0056] In a specific application test of this embodiment, as Figure 3As shown, it is the single-pulse discharge waveform of the high- and low-voltage power supplies collected by the oscilloscope. Δt1 is the breakdown delay interval, Δt2 is the spark discharge interval (usually 0 - 10 -5 seconds), and Δt3 is the arc discharge interval. It can be seen from the figure that when the high-voltage breakdown voltage and the low-voltage discharge voltage in the same medium are certain, the high-voltage breakdown delay interval Δt1 is a fixed value, the spark discharge interval Δt2 is a fixed value, and the only variable is the arc discharge interval Δt3. When Δt3 changes from 0 to +∞, the pulsed discharge becomes a DC discharge. From the above analysis, it is known that theoretically any pulsed discharge with a pulse width greater than 10 -5 seconds has an arc discharge component. Therefore, the energy of the arc discharge can be controlled by controlling the discharge voltage and current in the Δt3 section, and thus the machining accuracy can be controlled.

[0057] Therefore, in this embodiment, the first pulse generator, the second pulse generator, the first IGBT tube, and the second IGBT tube can output pulsed discharge. The first pulse generator and the second pulse generator can accurately control the voltage and current of the pulsed discharge, control the energy of the arc discharge, thereby improving the machining accuracy. Especially under the ultra-high voltage excitation of the dielectric breakdown circuit, it can achieve high-precision control while processing at high efficiency, breaking through the bottleneck of low machining accuracy in traditional arc machining.

[0058] Through the composite design of the dielectric breakdown circuit and the arc power supply circuit, the integrated application of high-voltage short pulses and low-voltage long pulses is realized, making the arc discharge process more stable and the electro-erosion products easier to discharge, thereby improving the quality of the machined surface and reducing surface defects. The machining system and method of this embodiment can achieve a lower surface roughness (Ra < 5μm) at a higher efficiency, and the machining accuracy can reach 0.02 mm, meeting the requirements of high-precision machining. It is especially suitable for aerospace structural parts that require large allowance removal and high machining accuracy. The arc machining system and working method of this embodiment can ensure the best balance between the material removal rate and the machining accuracy, greatly improving the machining ability of aerospace structural parts, and can improve the level of aerospace manufacturing industry, having great practical application value.

[0059] Embodiment 3

[0060] This embodiment provides an ultra-high voltage excitation variable pulse energy arc machining machine tool, which includes a water tank, a water pump, a three-axis drive system, a workpiece platform, an electrode, a machine tool control system, etc., and also includes the ultra-high voltage excitation variable pulse energy arc machining system described in Embodiment 1, a water tank 5, a water pump 6, a three-axis drive system, a workpiece platform, an electrode, a machine tool control system CNC, etc. The three-axis drive system includes an X-axis drive system 7, a Y-axis drive system 8, and a Z-axis drive system 9 connected to the electrode. The water pump 6 is connected to a water pipe. The above devices can adopt existing technologies and will not be described in detail here.

[0061] When machining a workpiece using the machining tool of this embodiment, for a workpiece material with higher hardness, the pulse width is adjusted to increase to provide more energy for material removal; for a workpiece material with softer hardness, the pulse width is reduced to reduce the influence of the arc on the workpiece and improve the surface quality.

[0062] The above are only the preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, various changes and modifications can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the protection scope of the present application.

Claims

1. A pulsed energy arc machining system for ultra-high voltage excitation transformers, including an arc power supply circuit, on which a first power supply and a first diode are sequentially connected in series. It is characterized in that, A first switching element is also serially arranged on the arc power supply circuit. A dielectric breakdown circuit is further included. A second power supply, a second switching element, and a second diode are serially arranged on the dielectric breakdown circuit in sequence. After the arc power supply circuit and the workpiece dielectric breakdown circuit are connected in parallel, they are connected to the power supply loop, and the power supply loop is used to connect the machine tool electrode and the workpiece; The output voltage of the second power supply is greater than that of the first power supply. When the second switching element controls the dielectric breakdown circuit to be connected to the power supply loop, the current output by the second power supply can break down the workpiece dielectric.

2. The ultra-high voltage excitation variable pulse energy arc machining system according to claim 1, characterized in that, The output voltage of the second power supply is 900V - 1100V, preferably 1000V, and the output voltage of the first power supply is 75V - 85V, preferably 80V.

3. A pulsed energy arc machining system for ultra-high voltage excitation transformers as claimed in claim 1, wherein, The first switching element uses a first IGBT tube, and the first IGBT tube is connected to a first pulse generator.

4. The ultra-high voltage excitation variable pulse energy arc machining system according to claim 3, characterized in that, The first pulse generator can enable the arc power supply circuit to generate a pulsed current with a pulse width of 0 - 1000 milliseconds and a frequency of 4 - 6Hz through the first IGBT tube.

5. The ultra-high voltage excitation variable pulse energy arc machining system according to claim 1, wherein The second switching element uses a second IGBT tube, and the second IGBT tube is connected to a second pulse generator.

6. The ultra-high voltage excitation variable pulse energy arc machining system according to claim 5, characterized in that, The second pulse generator can enable the dielectric breakdown circuit to generate a pulsed current with a pulse width of 1 microsecond to 10 microseconds and a frequency of 45Hz - 55Hz through the second IGBT tube.

7. The ultra-high voltage excitation variable pulse energy arc machining system according to claim 1, characterized in that, An independent detection circuit for connecting the workpiece and the machine tool electrode is further included. A third power supply, a fixed-value resistor, a Hall sensor, and a third diode are serially connected to the independent detection circuit in sequence.

8. The ultra-high voltage excitation variable pulse energy arc machining system according to claim 7, characterized in that, One end of the Hall sensor is grounded, and the other end is used as the output end of the independent detection circuit and is connected to the input end of the voltage stabilizing circuit. The output end of the voltage stabilizing circuit is connected to the positive terminal port of the voltage comparator in the voltage comparison circuit, and the output end of the voltage comparison circuit is connected to the controller.

9. A working method of the ultra-high voltage excitation variable pulse energy arc machining system according to any one of claims 1 - 8, characterized in that: The second switching element controls the dielectric breakdown circuit to conduct, and the second power supply outputs current to break down the workpiece dielectric and form a stable discharge channel; After the second switching element is disconnected, the first switching element conducts the arc power supply circuit, and the second power supply outputs current to perform arc machining on the workpiece.

10. A pulsed energy arc machining machine tool for ultra-high voltage excitation, characterized in that, An ultra-high voltage excitation variable pulse energy arc machining system according to any one of claims 1 - 8 is provided.

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