A power supply device and forming process control method for an electron gun manufactured in space additive manufacturing

Abstract

This application relates to a power supply device and forming process control method for an electron gun in space additive manufacturing. It is applicable to on-orbit additive manufacturing of cold cathode electron guns and is a device that can provide negative high voltage, pulsed current, and electrostatic field voltage to regulate the operating voltage of the filament coaxial cold cathode electron gun and promote droplet transfer in a microgravity environment. Addressing the shortcomings of existing technologies and the unique characteristics of the microgravity additive manufacturing environment, this application proposes a power supply device for a space additive manufacturing electron gun by setting an electrostatic field terminal at the beam output end of the filament coaxial cold cathode electron gun to provide it with an electrostatic field voltage, causing the droplets to be subjected to electrostatic force and accelerating droplet transfer. To ensure the orderly and controllable deposition and forming of metal droplets in a microgravity environment, a pulsed current is introduced to further promote droplet transfer. Through the above methods, the power supply device and forming process control method for the space additive manufacturing electron gun provided in this application meet the requirements for efficient, high-quality, and rapid manufacturing of filament coaxial cold cathode electron guns in the space environment.

Description

Technical Field

[0001] This application relates to the field of electron beam additive manufacturing technology, and in particular to a power supply device and forming process control method for an electron gun used in space additive manufacturing. Background Technology

[0002] Manned spacecraft and space stations are crucial for human space exploration. To improve the long-term stability and reliability of these vehicles, a large number of spare parts are typically stored within a limited space, severely compressing the living and experimental space for astronauts. Simultaneously, an equal number of spare parts need to be stored on the ground for immediate launch. However, only a very small percentage of these spare parts are actually used for replacement, less than 5%. To address all potential failures of the vehicles in orbit, various types of spare parts are needed to handle unforeseen malfunctions. The spare parts inventory far exceeds the number of components that might be used in the future, inevitably leading to a significant waste of resources in providing support for deep-space manned spaceflight. In future space exploration, the space trusses required for ultra-large area antennas and on-orbit service platforms are indispensable. Their geometric dimensions often need to reach hundreds or even tens of kilometers in length, with a mass reaching tens of thousands of tons. Such large-scale structures are almost impossible to implement using the conventional "ground manufacturing, rocket transportation, space application" model.

[0003] Additive manufacturing technology makes it possible for astronauts to manufacture spacecraft repair parts and large trusses in orbit. However, not all additive manufacturing technologies are suitable for the extreme environment of space. Compared with other additive manufacturing technologies, electron beam filament additive manufacturing technology has become an important direction for the development of on-orbit additive manufacturing technology due to its advantages such as high electron beam energy conversion efficiency, suitability for vacuum environments, and ease of filament confinement, with promising application prospects. NASA considers on-orbit additive manufacturing technology as one of the key technologies supporting deep space exploration missions. The Electron Beam Freeform (EBF3) system developed by NASA's Langley Research Center has been tested in a microgravity environment simulated by a jet aircraft. Currently, the common axial wire feeding mode of electron beam filament additive manufacturing technology in microgravity environments has shortcomings such as difficulty in filament alignment, the existence of heated shadow areas, and excessive heat input, which limits its future development potential. Summary of the Invention

[0004] This application provides a power supply device and a forming process control method for an electron gun in space additive manufacturing, which meets the requirements for long-term stable operation of the electron gun in space additive manufacturing and effectively improves forming quality and forming efficiency.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] This application provides a power supply device for a space additive manufacturing electron gun, comprising:

[0007] High-voltage power supply, pulse power supply, electrostatic field power supply, DSP control system, air flow controller, host computer;

[0008] The negative terminal of the high-voltage power supply is connected to the ring cathode, and the positive terminal of the high-voltage power supply is connected to the metal substrate through the beam sampling resistor; the negative terminal of the pulse power supply is connected to the metal wire disc support, and the positive terminal of the pulse power supply is grounded; the negative terminal of the electrostatic field power supply is connected to the electrostatic field terminal, and the positive terminal of the electrostatic field power supply is grounded; the DSP control system is connected to the high-voltage power supply, pulse power supply, electrostatic field power supply, gas flow controller, and host computer respectively; the gas flow controller is connected to the electron gun chamber.

[0009] The DSP control system is used to: receive the start command from the host computer; control the output voltage of the high-voltage power supply and adjust the beam current in the electron beam energy focusing region; control the output pulse current of the pulse power supply to regulate the droplet transition rate; control the output voltage of the electrostatic field power supply to accelerate the transition of the droplets to the substrate; and control the gas flow rate output by the gas flow controller to adjust the beam current.

[0010] Furthermore, the high-voltage power supply includes: a high-voltage power supply reverse connection protection unit, a high-voltage power supply first inverter unit, a high-voltage power supply first transformer unit, a high-voltage power supply first rectifier circuit, a high-voltage power supply second inverter unit, a high-voltage power supply second transformer unit, a high-voltage power supply second rectifier circuit, a high-voltage power supply voltage sensor, a high-voltage DC power supply control circuit, a high-voltage power supply first inverter drive circuit, a high-voltage inverter power supply control circuit, and a high-voltage power supply second inverter drive circuit.

[0011] The high-voltage power supply reverse connection protection unit takes DC power as input and includes diode D0, diode D1, inductor L0, and capacitor C0. The anode of diode D0 is connected to the positive terminal of the DC power supply, and the cathode of diode D0 is connected to one end of inductor L0. The cathode of diode D1 is connected to the negative terminal of the DC power supply, and the anode of diode D1 is connected to one end of capacitor C0. The other end of capacitor C0 is connected to the end of inductor L0 that is not connected to diode D0.

[0012] The output terminal of the high-voltage power supply reverse connection protection unit is connected to the first high-voltage power supply inverter unit, which is a full-bridge circuit composed of power switching devices; the output terminal of the first high-voltage power supply inverter unit is connected to the power transformer T of the first high-voltage power supply transformer unit. 10 The primary side, power transformer T 10 The secondary side is connected to the input terminal of the first rectifier circuit of the high-voltage power supply; the output terminal of the first rectifier circuit of the high-voltage power supply is connected in parallel with the high-voltage power supply voltage sensor; the high-voltage power supply voltage sensor detects the output voltage signal U of the first rectifier circuit of the high-voltage power supply. f , will U f Feedback is sent to the high-voltage DC power supply control circuit;

[0013] The output of the first rectifier circuit of the high voltage power supply is connected to the second inverter unit of the high voltage power supply. The second inverter unit of the high voltage power supply is also a full-bridge circuit composed of power switching devices. The gate of each power switching device is connected to the second inverter drive circuit of the high voltage power supply. The second inverter drive circuit of the high voltage power supply receives the PWM signal from the control circuit of the high voltage inverter power supply and controls each power switching device to turn on at full frequency and full pulse width.

[0014] The second rectifier circuit of the high-voltage power supply includes a high-voltage diode D. 11 D 12 D 13 D 14 The rectifier bridge and high-voltage diode D are composed of 15 D 16 D 17 D 18 The rectifier bridge consists of high-voltage diode D. 11 D 12 D 13 D 14 The positive terminal of the rectifier bridge is connected to the high-voltage diode D. 15 D 16 D 17 D 18 The negative end of the rectifier bridge is connected;

[0015] The output of the second inverter unit of the high-voltage power supply is connected to the second transformer unit of the high-voltage power supply. The second transformer unit of the high-voltage power supply includes two high-voltage transformers T. 11 T 12 High-voltage transformer T 11 T 12 The primary side is connected in parallel to the output terminal of the second inverter unit of the high-voltage power supply, and the high-voltage transformer T 11 The two ends of the secondary side are respectively connected to the high-voltage diode D. 11 D 12 D 13 D 14 The rectifier bridge is composed of; the high-voltage transformer T 12 The two ends of the secondary side are respectively connected to the high-voltage diode D. 15 D 16 D 17 D 18 The rectifier bridge is composed of;

[0016] The negative output terminal of the second rectifier circuit of the high-voltage power supply is connected to the ring cathode; the positive output terminal of the second rectifier circuit of the high-voltage power supply is connected to one end of the beam sampling resistor R1, and the beam sampling signal I... bf Take it from one end of the beam sampling resistor R1, and connect the other end of the beam sampling resistor R1 to the reference ground.

[0017] Furthermore, a high-voltage sampling circuit is connected in parallel between the negative and positive output terminals of the second rectifier circuit of the high-voltage power supply. This high-voltage sampling circuit includes several voltage-dividing resistors and a high-voltage sampling resistor R0. The voltage-dividing resistors and the high-voltage sampling resistor R0 are connected in series, and the high-voltage feedback signal U is acquired at the connection points of these resistors and R0. hvf The other end of the high-voltage sampling resistor R0 is connected to the positive output terminal of the second rectifier circuit of the high-voltage power supply.

[0018] High voltage feedback signal U hvf Feedback is sent to the DSP control system, which then uses the high-voltage given signal U... hvg With high voltage feedback signal U hvf Perform PID control and output U hvgg The signal is sent to the high-voltage DC power supply control circuit, which simultaneously receives the output voltage signal U from the first rectifier circuit of the high-voltage power supply detected by the high-voltage power supply voltage sensor. f ;

[0019] U f with U hvgg After PID regulation by the high-voltage DC power supply control circuit, the pulse width of the output PWM signal is adjusted. Then, after passing through the first inverter drive circuit of the high-voltage power supply, four PWM signals are output to the gates of each power switching device in the full-bridge circuit of the first inverter unit of the high-voltage power supply, adjusting the conduction time of the corresponding power switching devices, thereby adjusting the output voltage of the first rectifier circuit and the output voltage of the second rectifier circuit of the high-voltage power supply, and realizing the adjustment of the negative high voltage output of the high-voltage power supply to the ring cathode.

[0020] Furthermore, the pulse power supply includes: a pulse power supply reverse connection protection unit, a pulse power supply inverter unit, a pulse power supply transformer unit, a pulse power supply rectifier circuit, a pulse power supply discharge switch, a pulse power supply discharge switch drive circuit, a pulse power supply current sensor, and a filter inductor L. 202 Charging capacitor C 202 Pulse power supply control circuit, pulse power supply inverter drive circuit;

[0021] The pulse power reverse connection protection unit receives DC power as input and includes diode D. 201 Diode D 202 Inductor L 201 Capacitor C 201 diode D 201 The anode of diode D is connected to the positive terminal of the DC power supply. 201 Cathode connection inductor L 201 One end; diode D 202 The cathode of diode D is connected to the negative terminal of the DC power supply. 202Anode connection capacitor C 201 One end, capacitor C 201 The other end is connected to inductor L 201 Not with diode D 201 One end of the connection;

[0022] The output of the pulse power reverse connection protection unit is connected to the pulse power inverter unit, which is a bridge circuit composed of power switching devices; the output of the pulse power inverter unit is connected to the transformer T of the pulse power transformer unit. 20 The primary side of the transformer T 20 The two ends of the secondary side are respectively connected to diode D 21 D 22 D 23 D 24 The input terminal of the pulse power supply rectifier circuit;

[0023] The negative output terminal of the pulse power rectifier circuit is connected to the filter inductor L. 202 One end, filter inductor L 202 The other end is connected in series with a pulse power current sensor and then connected to a charging capacitor C. 202 One end, the charging capacitor C 202 The other end is connected to the positive output terminal of the pulse power rectifier circuit; the positive output terminal of the pulse power rectifier circuit is also connected to a current-limiting resistor R. 201 One end, current-limiting resistor R 201 The other end is grounded;

[0024] Filter inductor L 202 With charging capacitor C 202 The common point of connection is connected to the emitter of the pulse power discharge switch. The pulse power discharge switch is composed of a single high-power IGBT or multiple IGBTs connected in parallel. The collector of the pulse power discharge switch is connected to the metal wire spool support. The metal wire spool support is insulated from the ground.

[0025] Furthermore, the charging capacitor C 202 A pulse power supply voltage sensor is connected in parallel across both ends. When the pulse power supply discharge switch is not turned on, the pulse power supply voltage sensor will collect the charging voltage signal U. pf Feedback is sent to the pulse power control circuit, which then transmits the charging voltage signal U given by the DSP control system. pgg with U pf Compare;

[0026] If U pgg >U pf The pulse power supply control circuit uses the charging current signal I collected by the pulse power supply current sensor. pfAdjusting the PWM pulse width changes the on / off time of the power switching devices in the pulse power inverter unit after passing through the pulse power inverter drive circuit, thus affecting the charging capacitor C. 202 Perform constant current charging; if U pgg =U pf The pulse power supply control circuit uses the charging voltage signal U collected by the pulse power supply voltage sensor. pf Adjusting the PWM pulse width affects the charging capacitor C. 202 Perform constant voltage charging to make the charging capacitor C 202 The stored electrical energy is stable.

[0027] Furthermore, the DSP control system also receives the droplet morphology status signal obtained by the host computer through machine vision. When the host computer determines that the droplet can detach from the wire end and transition to the metal substrate, the host computer outputs a droplet transition enable signal to the DSP control system.

[0028] The DSP control system detects and feeds back the charging voltage signal U. pf Has the set charging voltage U been reached? pgg If this is achieved, the DSP control system will issue a pulse power discharge switch on signal I. pIO The signal is transmitted to the base of the pulse power discharge switch through the pulse power discharge switch drive circuit, causing the pulse power discharge switch to conduct.

[0029] During the pulse power discharge switch's on-time period, the DSP control system adjusts the charging voltage U. pgg If the signal is zero, the pulse power supply control circuit will not output a PWM signal, and the power switching devices in the pulse power supply inverter unit will not operate; at the end of the discharge, the DSP control system will adjust the charging voltage U. pgg The signal has been restored to the set value.

[0030] Furthermore, the electrostatic power supply includes: an electrostatic power supply reverse connection protection unit, an electrostatic power supply inverter unit, an electrostatic power supply transformer unit, an electrostatic power supply rectifier circuit, an electrostatic power supply control circuit, and an electrostatic power supply inverter drive circuit.

[0031] The electrostatic field power supply reverse connection protection unit receives DC power as input and includes a diode D. 301 Diode D 302 Inductor L 301 Capacitor C 301 diode D 301 The anode of diode D is connected to the positive terminal of the DC power supply. 301 Cathode connection inductor L 301 One end; diode D 302 The cathode of diode D is connected to the negative terminal of the DC power supply. 302 Anode connection capacitor C301 One end, capacitor C 301 The other end is connected to inductor L 301 Not with diode D 301 One end of the connection;

[0032] The output of the electrostatic field power supply reverse connection protection unit is connected to the electrostatic field power supply inverter unit, which is a bridge circuit composed of power switching devices; the output of the electrostatic field power supply inverter unit is connected to the transformer T of the electrostatic field power supply transformer unit. 30 The primary side of the transformer T 30 The two ends of the secondary side are respectively connected to diode D 31 D 32 D 33 D 34 The input terminal of the electrostatic field power supply rectifier circuit;

[0033] The positive output terminal of the electrostatic field power supply rectifier circuit is grounded; the negative output terminal of the electrostatic field power supply rectifier circuit is connected to the filter inductor L. 302 One end, filter inductor L 302 The other end is connected to the filter inductor L 303 One end, filter inductor L 303 The other end is connected to a current-limiting resistor R. 301 Connected to the electrostatic field terminal; filter inductor L 302 With the filter inductor L 303 The common connection point is connected to the filter capacitor C. 302 One end, filter capacitor C 302 The other end is grounded.

[0034] Furthermore, the filter capacitor C shown... 302 An electrostatic field power supply voltage sensor is connected in parallel across both ends. The electrostatic field power supply voltage sensor will collect the electrostatic field voltage signal U. dcf Transmitted to the electrostatic field power control circuit;

[0035] The electrostatic field power supply control circuit will use the U given by the DSP control system dcgg with U dcf PID control is performed to adjust the output PWM pulse width, which in turn controls the on / off time of the power switching devices in the electrostatic power inverter unit through the electrostatic power inverter drive circuit, thereby maintaining a stable voltage at the electrostatic terminals; U dcgg It is the electrostatic field voltage given signal U from the external circuit. dcg The signal obtained after digital filtering.

[0036] This application also provides a method for controlling the forming process of a space additive manufacturing electron gun, including:

[0037] The host computer receives the additive manufacturing start command and transmits the operation start command to the DSP control system. The DSP control system then executes the operation based on the high-voltage given signal U. hvg With high voltage feedback signal U hvf Perform PID control and output U hvgg The signal is sent to the high-voltage DC power supply control circuit to make the working voltage of the ring cathode connected to the output terminal of the high-voltage power supply reach the set value.

[0038] The DSP control system is based on the beam current given I bg and beam feedback I bf PID control is performed to convert the airflow into a setpoint signal U. ggas The signal is transmitted to the air flow controller, which then transmits the air flow signal U. gas The gas is transmitted to the gas flow meter, which then transmits the working gas through the gas guide tube into the electron gun chamber to adjust the beam size.

[0039] The DSP control system activates the pulse power discharge switch signal I. pIO When the signal is low, the pulse power supply discharge switch is not turned on; the DSP control system responds to the pulse current given signal I. pg The corresponding charging voltage signal U can be obtained by consulting the current-to-voltage conversion parameter table. pgg The DSP control system transmits this information to the pulse power supply control circuit, which then controls the charging capacitor C. 202 The highest charging voltage;

[0040] The DSP control system receives the electrostatic field voltage command signal U from the external circuit. dcg After digital filtering, the output U dcgg The electrostatic field power supply control circuit ensures that the voltage at the electrostatic field terminals reaches the set value.

[0041] The host computer controls the wire feeding mechanism to feed the metal wire at a preset speed. The metal wire is heated and melted at the convergence point of the annular electron beam. The molten metal forms droplets under the action of surface tension. The droplet morphology status signal obtained by machine vision is transmitted to the host computer.

[0042] If the host computer determines that the three-dimensional size of the molten droplet has reached the preset value, it outputs a droplet transition enable signal to the DSP control system. The DSP control system detects the feedback charging voltage signal U. pf Has the set charging voltage U been reached? pgg ;

[0043] If U pf Upon reaching the set value, the DSP control system outputs a pulse power discharge switch on signal I. pIO The signal is high, turning on the pulse power supply discharge switch; simultaneously, the DSP control system increases the charging voltage U.pgg The signal remains zero until the discharge ends, at which point the DSP control system outputs a pulse power discharge switch on signal I. pIO The signal is low, causing the pulse power supply discharge switch to turn off; the DSP control system adjusts the charging voltage U. pgg The signal has been restored to the set value;

[0044] After the molten droplet transitions to the metal substrate, the host computer moves the electron gun to the next deposition point according to the preset trajectory, repeating the above steps until the shape is completed according to the preset model.

[0045] Furthermore, it also includes:

[0046] The host computer sends a stop signal to the wire feeding mechanism, stopping the wire feeding. The host computer also sends a run-end command to the DSP control system, which outputs a U... hvgg When the signal is low, the output of the high-voltage power supply is zero.

[0047] DSP control system enables U ggas When the value is zero, the gas flow controller is turned off, and the DSP control system activates the pulse power discharge switch signal I. pIO When the voltage is low, the pulse power supply discharge switch is not turned on, and the DSP control system makes the charging voltage signal U... pgg The value is zero, causing the pulse power supply to stop working. The DSP control system then makes U... dcgg The value is zero, which disables the electrostatic power supply.

[0048] The power supply device and forming process control method of the electron gun for space additive manufacturing provided in this application, under microgravity conditions, because the metal droplet carries a negative charge and the electrostatic field terminal carries a negative charge, and there is a negative electric field between the electrostatic field terminal and the substrate, the droplet is constrained by the electrostatic field force and can grow in a controllable manner, without climbing back along the filament or drifting around; at the same time, under the action of the electric field force, the transition of the metal droplet to the metal substrate can be accelerated; when the droplet contacts the substrate, a circuit is formed between the metal substrate-droplet-filament-metal filament disk-metal filament disk support-pulse current source, and the large pulse current applied to the filament causes an electromagnetic force from a small cross section to a large cross section to be generated at the necking point where the filament and the droplet are connected, which can further promote the droplet transition, and the droplet transition rate can be controlled by adjusting the amplitude of the pulse current. Attached Figure Description

[0049] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0050] Figure 1 A schematic diagram of the power supply device for the space additive manufacturing electron gun provided in this application;

[0051] Figure 2 A schematic diagram of the high-voltage power supply provided in this application;

[0052] Figure 3 A schematic diagram of the pulse power supply provided in this application;

[0053] Figure 4 A schematic diagram of the electrostatic field power supply provided in this application;

[0054] Figure 5 A flowchart illustrating the forming process control method for the electron gun in space additive manufacturing provided in this application.

[0055] Reference numerals: 1. High-voltage power supply; 101. High-voltage power supply reverse connection protection unit; 102. High-voltage power supply first inverter unit; 103. High-voltage power supply first transformer unit; 104. High-voltage power supply first rectifier circuit; 105. High-voltage power supply second inverter unit; 106. High-voltage power supply second transformer unit; 107. High-voltage power supply second rectifier circuit; 108. High-voltage power supply high-voltage sampling circuit; 109. High-voltage power supply voltage sensor; 110. High-voltage DC power supply control circuit; 111. High-voltage power supply first inverter drive circuit; 112. High-voltage inverter power supply control circuit; 113. High-voltage power supply second inverter drive circuit; 2. Pulse power supply; 201. Pulse power supply reverse connection protection unit; 202. Pulse power supply inverter unit; 203. Pulse power supply transformer unit; 204. Pulse power supply rectifier circuit; 205. Pulse power supply discharge switch; 206. Pulse power supply 1. Discharge switch drive circuit; 207. Pulse power supply voltage sensor; 208. Pulse power supply current sensor; 209. Pulse power supply control circuit; 210. Pulse power supply inverter drive circuit; 3. Electrostatic field power supply; 301. Electrostatic field power supply reverse connection protection unit; 302. Electrostatic field power supply inverter unit; 303. Electrostatic field power supply transformer unit; 304. Electrostatic field power supply rectifier circuit; 305. Electrostatic field power supply voltage sensor; 306. Electrostatic field power supply control circuit; 307. Electrostatic field power supply inverter drive circuit; 4. DSP control system; 5. Gas flow controller; 51. Gas flow meter; 6. Ring cathode; 7. Electrostatic field terminal; 8. Electron gun chamber; 9. Metal substrate; 10. Metal wire spool support; 11. Metal wire spool; 12. Metal wire; 13. Electron beam; 14. Metal droplet; 15. Anode; 16. Gas guide tube; 17. Host computer. Detailed Implementation

[0056] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of this application with unnecessary detail.

[0057] It should be understood that, when used in this application specification and the appended claims, the term "comprising" indicates the presence of the described features, integrals, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or a collection thereof.

[0058] Furthermore, in the description of this application and the appended claims, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0059] References to "one embodiment" or "some embodiments" in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized. "A plurality" means "two or more."

[0060] The specific embodiments of this application will be described in further detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this application, but are not intended to limit the scope of this application.

[0061] like Figure 1 As shown, this embodiment provides a power supply device for a space additive manufacturing electron gun, which mainly includes: a high-voltage power supply 1, a pulse power supply 2, an electrostatic field power supply 3, a DSP control system 4, an air flow controller 5, and a host computer 17.

[0062] like Figure 2As shown, the high-voltage power supply 1 includes: a high-voltage power supply reverse connection protection unit 101, a high-voltage power supply first inverter unit 102, a high-voltage power supply first transformer unit 103, a high-voltage power supply first rectifier circuit 104, a high-voltage power supply second inverter unit 105, a high-voltage power supply second transformer unit 106, a high-voltage power supply second rectifier circuit 107, a high-voltage power supply high-voltage sampling circuit 108, a high-voltage power supply voltage sensor 109, a high-voltage power supply control circuit 110, a high-voltage power supply first inverter drive circuit 111, a high-voltage inverter power supply control circuit 112, and a high-voltage power supply second inverter drive circuit 113.

[0063] The high-voltage power supply reverse connection protection unit 101 has a DC 100V input. It consists of diodes D0 and D1, inductor L0, and capacitor C0. The anode of diode D0 is connected to the positive terminal of the DC 100V power supply, and the cathode of diode D0 is connected to one end of inductor L0. The cathode of diode D1 is connected to the negative terminal of the DC 100V power supply, and the anode of diode D1 is connected to one end of capacitor C0. The other end of capacitor C0 is connected to the end of inductor L0 that is not connected to diode D0. Inductor L0 and capacitor C0 form an LC filter circuit. This connection method between diodes D0 and D1 and the positive and negative terminals of the DC 100V power supply in the high-voltage power supply reverse connection protection unit 101 can prevent damage to the DC 100V power supply due to operational errors.

[0064] The output terminal of the high-voltage power supply reverse connection protection unit 101 is connected to the high-voltage power supply first inverter unit 102, which is a full-bridge circuit composed of power switching devices; the output terminal of the high-voltage power supply first inverter unit 102 is connected to the power transformer T of the high-voltage power supply first transformer unit 103. 10 The primary side, power transformer T 10 The primary-to-secondary transformation ratio is 1:6. The power transformer T of the first transformer unit 103 of the high-voltage power supply... 10 The secondary side is connected to the input terminal of the first rectifier circuit 104 of the high-voltage power supply; the output terminal of the first rectifier circuit 104 of the high-voltage power supply is connected in parallel with the high-voltage power supply voltage sensor 109. The high-voltage power supply voltage sensor 109 detects the output voltage signal U of the first rectifier circuit 104 of the high-voltage power supply. f , will U f Feedback is sent to the high-voltage power supply control circuit 110.

[0065] The output terminal of the first rectifier circuit 104 of the high-voltage power supply is connected to the second inverter unit 105 of the high-voltage power supply. The second inverter unit 105 of the high-voltage power supply is also a full-bridge circuit composed of power switching devices. The gates of each power switching device in the full-bridge circuit are respectively connected to the second inverter drive circuit 113 of the high-voltage power supply. The second inverter drive circuit 113 of the high-voltage power supply receives the PWM signal from the control circuit 112 of the high-voltage inverter power supply and controls each power switching device in the full-bridge circuit of the second inverter unit 105 of the high-voltage power supply to turn on at full frequency and full pulse width.

[0066] The output terminal of the second inverter unit 105 of the high-voltage power supply is connected to the second transformer unit 106 of the high-voltage power supply. The second transformer unit 106 of the high-voltage power supply consists of two high-voltage transformers T. 11 T 12 Composition, high-voltage transformer T 11 T 12 The primary side is connected in parallel to the output terminal of the second inverter unit 105 of the high-voltage power supply; the high-voltage transformer T 11 T 12 The turns ratios of both the primary and secondary sides are 1:27. High-voltage transformer T 11 The two ends of the secondary side are respectively connected to the high-voltage diode D. 11 D 12 D 13 D 14 Points A and B that form the rectifier bridge; high-voltage transformer T 12 The two ends of the secondary side are respectively connected to the high-voltage diode D. 15 D 16 D 17 D 18 Points E and F that make up the rectifier bridge.

[0067] High voltage diode D 11 D 12 D 13 D 14 The positive terminal of the rectifier bridge is connected to the high-voltage diode D. 15 D 16 D 17 D 18 The negative terminal of the rectifier bridge is connected to point O; the high-voltage diode D 11 D 12 D 13 D 14 The rectifier bridge and high-voltage diode D are composed of 15 D 16 D 17 D 18 The rectifier bridges together form the second rectifier circuit 107 of the high-voltage power supply.

[0068] The negative output terminal of the second rectifier circuit 107 of the high-voltage power supply is connected to the ring cathode 6; the positive output terminal of the second rectifier circuit 107 of the high-voltage power supply is connected to one end of the beam sampling resistor R1, and the beam sampling signal I... bf Take it from one end of the beam sampling resistor R1, and connect the other end of the beam sampling resistor R1 to the reference ground.

[0069] A high-voltage power supply high-voltage sampling circuit 108 is also connected in parallel between the negative and positive output terminals of the second rectifier circuit 107 of the high-voltage power supply. The high-voltage power supply high-voltage sampling circuit 108 consists of a voltage divider resistor R. a1 R a2 It consists of ... and the high-voltage sampling resistor R0; the voltage divider resistor R a1 R a2 ...and the high-voltage sampling resistor R0 are connected in series in sequence, with the voltage divider resistor R... a1 R a2 ...and the high-voltage feedback signal U is acquired at the connection point with the high-voltage sampling resistor R0. hvf The other end of the high-voltage sampling resistor R0 is connected to the positive output terminal of the second rectifier circuit 107 of the high-voltage power supply.

[0070] High voltage feedback signal U hvf Feedback is sent to DSP control system 4, which then uses the high-voltage given signal U... hvg With high voltage feedback signal U hvf Perform PID control and output U hvgg The signal is sent to the high-voltage DC power supply control circuit 110, which simultaneously receives the output voltage signal U from the high-voltage power supply voltage sensor 109, which detects the output voltage signal U from the first rectifier circuit 104 of the high-voltage power supply. f U f with U hvgg After PID regulation by the high-voltage DC power supply control circuit 110, the pulse width of the output PWM signal is adjusted. Then, after passing through the high-voltage power supply first inverter drive circuit 111, four PWM signals are output to the gates of each power switching device in the full-bridge circuit of the high-voltage power supply first inverter unit 102, adjusting the conduction time of the corresponding power switching devices, thereby adjusting the output voltage of the high-voltage power supply first rectifier circuit 104; subsequently, the output voltage of the high-voltage power supply second rectifier circuit 107 is adjusted, that is, the negative high voltage output from the high-voltage power supply 1 to the annular cathode 6 is adjusted.

[0071] like Figure 3 As shown, the pulse power supply 2 mainly consists of a pulse power supply reverse connection protection unit 201, a pulse power supply inverter unit 202, a pulse power supply transformer unit 203, a pulse power supply rectifier circuit 204, a pulse power supply discharge switch 205, a pulse power supply discharge switch drive circuit 206, a pulse power supply voltage sensor 207, a pulse power supply current sensor 208, and a filter inductor L. 202Charging capacitor C 202 It consists of a pulse power supply control circuit 209 and a pulse power supply inverter drive circuit 210.

[0072] The pulse power reverse connection protection unit 201 has a DC input of 100V and is composed of diode D. 201 Diode D 202 Inductor L 201 Capacitor C 201 Composition, in which diode D 201 The anode of diode D is connected to the positive terminal of a 100V DC circuit. 201 Cathode connection inductor L 201 One end; diode D 202 The cathode of diode D is connected to the negative terminal of a 100V DC circuit. 202 Anode connection capacitor C 201 One end, capacitor C 201 The other end is connected to inductor L 201 Not with diode D 201 One end of the connection, inductor L 201 Capacitor C 201 Composed of an LC filter circuit; diode D of pulse power supply reverse connection protection unit 201 201 Diode D 202 The connection method with the positive and negative terminals of a 100V DC power supply can prevent damage to the 100V DC power supply due to operational errors.

[0073] The output terminal of the pulse power reverse connection protection unit 201 is connected to the pulse power inverter unit 202, which is a bridge circuit composed of power switching devices; the output terminal of the pulse power inverter unit 202 is connected to the transformer T of the pulse power transformer unit 203. 20 The primary side of the transformer T 20 The primary-to-secondary turns ratio is 1:12. The transformer T in pulse power supply transformer unit 203... 20 The two ends of the secondary side are respectively connected to diode D 21 D 22 D 23 D 24 The A1 and B1 input terminals of the electrostatic field power rectifier circuit 204 are formed.

[0074] The negative output terminal of the pulse power rectifier circuit 204 is connected to the filter inductor L. 202 One end, filter inductor L 202 The other end is connected in series with the pulse power current sensor 208 and then connected to the charging capacitor C. 202 One end, the charging capacitor C 202The other end is connected to the positive output terminal of the pulse power rectifier circuit 204; the positive output terminal of the pulse power rectifier circuit 204 is also connected to a current-limiting resistor R. 201 One end, current-limiting resistor R 201 The other end is connected to the reference ground.

[0075] Filter inductor L 202 With charging capacitor C 202 The common point of connection is connected to the emitter of the pulse power discharge switch 205, which is composed of a single high-power IGBT or multiple IGBTs connected in parallel. The collector of the pulse power discharge switch 205 is connected to the wire spool support 10; the wire spool support 10 is insulated from the reference ground.

[0076] Charging capacitor C 202 A pulse power voltage sensor 207 is also connected in parallel at both ends. When the pulse power discharge switch 205 is not turned on, the pulse power voltage sensor 207 will collect the charging voltage signal U. pf Feedback is sent to the pulse power control circuit 209, which then transmits the charging voltage signal U from the DSP control system 4. pgg with U pf Compare, if U pgg >U pf The pulse power control circuit 209 uses the charging current signal I collected by the pulse power current sensor 208. pf Adjusting the PWM pulse width changes the on / off time of the power switching devices in the pulse power inverter unit 202 after passing through the pulse power inverter drive circuit 210, thus affecting the charging capacitor C. 202 Perform constant current charging; if U pgg =U pf The pulse power control circuit 209 controls the charging voltage signal U collected by the pulse power voltage sensor 209. pf Adjusting the PWM pulse width affects the charging capacitor C. 202 Perform constant voltage charging to make the charging capacitor C 202 The stored electrical energy is stable.

[0077] Charging capacitor C 202 The capacitance is not less than 2000μF, and the withstand voltage rating is not less than 2000V; the current-limiting resistor R 201 The resistance value is no greater than 1Ω.

[0078] When the pulse power discharge switch 205 is turned on, the pulse current flows from the charging capacitor C. 202 One end is connected via a pulse power discharge switch 205, a metal wire spool support 10, a metal wire spool 11, a metal wire 12, a molten droplet 14, a metal substrate 9, and a current-limiting resistor R. 201 Then, it flows to the charging capacitor C. 202At the other end, the pulsed current generates an electromagnetic force from a small cross-section to a large cross-section at the necking point where the metal wire 12 connects to the molten droplet 14, which will promote the transition of the molten droplet 14.

[0079] At the charging capacitor C 202 When the capacitance value is determined, the internal resistance of the pulse power supply discharge switch 205, the resistance values ​​of the metal wire support 10 and the metal wire 11, the resistance values ​​of the metal wire 12 and the molten droplet 14, the metal substrate 9 and the current limiting resistor R are considered. 201 When the resistance remains constant, the magnitude of the pulse current is determined by the charging capacitor C. 202 The maximum charging voltage is determined by a series of experiments to obtain the pulse current and charging capacitor C. 202 The voltage-to-current-to-voltage conversion parameter table is stored in the DSP control system 4. The DSP control system 4 uses the pulse current given signal I... pg The corresponding charging voltage signal U can be obtained by consulting the current-to-voltage conversion parameter table. pgg The DSP control system 4 transmits this information to the pulse power control circuit 209, which then determines the charging capacitor C. 202 The highest charging voltage is used to determine the magnitude of the pulse current.

[0080] The DSP control system 4 also receives droplet morphology status signals from the host computer 17 obtained through machine vision. When the host computer 17 determines that the droplet 14 can detach from the wire end and transition to the metal substrate 9, the host computer 17 outputs a droplet transition enable signal to the DSP control system 4. The DSP control system 4 detects the feedback charging voltage signal U. pf Has the set charging voltage U been reached? pgg If it doesn't reach the target, then wait for U. pf Reaching the set charging voltage U pgg ;U pf Upon reaching the set value, the DSP control system 4 outputs an on signal I to the pulse power discharge switch 205. pIO The signal is transmitted to the base of the pulse power discharge switch 205 via the pulse power discharge switch drive circuit 206, causing the pulse power discharge switch 205 to conduct. The conduction time t > 1 / 2 (RC), where R is the internal resistance of the pulse power discharge switch 205, the resistance of the metal wire support 10 and the metal wire 11, the resistance of the metal wire 12 and the molten droplet 14, and the resistance of the metal substrate 9 and the current limiting resistor R. 201 The sum of resistance values; C is the charging capacitor C. 202 The capacitance value.

[0081] During the period when the pulse power discharge switch 205 is turned on, the DSP control system 4 sets the charging voltage U pggIf the signal is zero, the pulse power control circuit 209 will not output a PWM signal, and the power switching devices in the pulse power inverter unit 202 will not work; when the discharge ends, the DSP control system 4 will set the charging voltage U... pgg The signal has been restored to the set value.

[0082] like Figure 4 As shown, the electrostatic power supply 3 mainly consists of an electrostatic power supply reverse connection protection unit 301, an electrostatic power supply inverter unit 302, an electrostatic power supply transformer unit 303, an electrostatic power supply rectifier circuit 304, an electrostatic power supply voltage sensor 305, an electrostatic power supply control circuit 306, and an electrostatic power supply inverter drive circuit 307.

[0083] The electrostatic field power supply reverse connection protection unit 301 has a DC input of 100V and is composed of diode D. 301 Diode D 302 Inductor L 301 Capacitor C 301 Composition, in which diode D 301 The anode of diode D is connected to the positive terminal of a 100V DC circuit. 301 Cathode connection inductor L 301 One end; diode D 302 The cathode of diode D is connected to the negative terminal of a 100V DC circuit. 302 Anode connection capacitor C 301 One end, capacitor C 301 The other end is connected to inductor L 301 Not with diode D 301 One end of the connection, inductor L 301 Capacitor C 301 Composed of an LC filter circuit; diode D of pulse power supply reverse connection protection unit 301 301 Diode D 302 The connection method with the positive and negative terminals of a 100V DC power supply can prevent damage to the 100V DC power supply due to operational errors.

[0084] The output terminal of the electrostatic field power supply reverse connection protection unit 301 is connected to the electrostatic field power supply inverter unit 302, which is a bridge circuit composed of power switching devices; the output terminal of the electrostatic field power supply inverter unit 302 is connected to the transformer T of the electrostatic field power supply transformer unit 303. 30 The primary side of the transformer T 30 The primary-to-secondary transformation ratio is 5:6. Transformer T 30 The two ends of the secondary side are respectively connected to diode D 31 D 32 D 33 D 34The A2 and B2 input terminals of the electrostatic field power rectifier circuit 304 are connected; the positive output terminal of the electrostatic field power rectifier circuit 304 is also connected to the reference ground; the negative output terminal of the electrostatic field power rectifier circuit 304 is connected to the filter inductor L. 302 One end, filter inductor L 302 The other end is connected to the filter inductor L 303 One end, filter inductor L 303 The other end is connected to a current-limiting resistor R. 301 Connect to electrostatic field terminal 7; filter inductor L 302 With the filter inductor L 303 The common connection point is connected to the filter capacitor C. 302 One end, filter capacitor C 302 The other end is connected to the reference ground; filter inductor L 302 Filter inductor L 303 Filter capacitor C 302 Form a "T" type filter circuit.

[0085] The filter capacitor C shown 302 An electrostatic field power supply voltage sensor 305 is connected in parallel across both ends. The electrostatic field power supply voltage sensor 305 will collect the electrostatic field voltage signal U. dcf The signal is transmitted to the electrostatic field power supply control circuit 306, which will receive the U signal from the DSP control system 4. dcgg with U dcf PID regulation is performed to adjust the width of the output PWM pulse. The turn-on / turn-off time of the power switching devices in the electrostatic field power inverter unit 302 is controlled by the electrostatic field power inverter drive circuit 307, thereby maintaining a stable voltage at the electrostatic field terminal 7.

[0086] The electrostatic field terminal 7 is negatively charged. Before the molten droplet 14 transitions to the substrate, the surface of the molten droplet 14 carries a large amount of negative charge. The electrostatic field terminal 7 repels the molten droplet 14, preventing it from climbing back along the metal wire 12 and promoting the controlled deposition of the molten droplet 14 toward the metal substrate 9. dcgg It is the electrostatic field voltage given signal U from the external circuit. dcg The signal obtained after digital filtering.

[0087] like Figure 5 As shown in the figure, this embodiment also provides a method for controlling the forming process of an electron gun in space additive manufacturing, as detailed below:

[0088] Step 1 S001, Multi-parameter preset: The host computer 17 receives the additive manufacturing start command through the human-machine interface and transmits the operation start command to the DSP control system 4. The DSP control system 4 then sets the parameters according to the high-voltage given signal U. hvg With high voltage feedback signal U hvfPerform PID control and output U hvgg The signal is sent to the high-voltage DC power supply control circuit 110, so that the working voltage of the ring cathode 6 connected to the output terminal of the high-voltage power supply 1 reaches the set value.

[0089] DSP control system 4 based on beam current input I bg and beam feedback I bf PID control is performed to convert the airflow into a setpoint signal U. ggas The gas flow signal Ugas is transmitted to the gas flow controller 5, which in turn transmits the gas flow signal Ugas to the gas flow meter 51. The gas flow meter 51 then transmits the working gas through the gas guide tube 16 into the electron gun chamber 8. Adjusting the amount of working gas entering the electron gun chamber 8 can achieve the purpose of adjusting the beam size.

[0090] The DSP control system 4 activates the pulse power discharge switch 205 via signal I. pIO When the signal is low, the pulse power discharge switch 205 is not turned on; the DSP control system 4 responds to the pulse current given signal I. pg The corresponding charging voltage signal U can be obtained by consulting the current-to-voltage conversion parameter table. pgg The DSP control system 4 transmits this information to the pulse power control circuit 209, which controls the charging capacitor C. 202 The highest charging voltage; change the pulse current given signal I pg That is, the charging capacitor C was changed. 202 The maximum charging voltage is adjusted accordingly to change the pulse current magnitude.

[0091] The DSP control system 4 receives the electrostatic field voltage command signal U from the external circuit. dcg After digital filtering, the output U dcgg The electrostatic field power control circuit 306 is used to make the voltage at the electrostatic field terminal 7 reach the set value.

[0092] Step 2 S002, Directional melting of wire: The host computer 17 controls the wire feeding mechanism to feed the metal wire 12 at a preset speed. At the convergence point of the annular electron beam, the metal wire 12 is heated and melted. The molten metal forms droplets 14 under the action of surface tension. As the metal wire 12 is fed in and heated and melted, the droplets 14 gradually grow within the electric field constraint range under the action of electrostatic force, avoiding the uncontrollable phenomenon of the droplets 14 climbing in the opposite direction along the metal wire 12 and drifting away due to disturbance.

[0093] Step 3 S003, Droplet Transition Judgment: The droplet morphology status signal obtained by machine vision is transmitted to the host computer 17. The host computer 17 judges whether the three-dimensional size of the droplet has reached the transition state. If the three-dimensional size of the droplet has not reached the preset value, the detection and judgment continue.

[0094] Step 4 S004, Controllable Droplet Transition: The host computer 17 determines that the three-dimensional size of the droplet has reached the preset value, and outputs a droplet transition enable signal to the DSP control system 4. The DSP control system 4 detects the feedback charging voltage signal U. pf Has the set charging voltage U been reached? pgg If it doesn't reach the target, then wait for U. pf Reaching the set charging voltage U pgg ;U pf Upon reaching the set value, the DSP control system 4 outputs an on signal I to the pulse power discharge switch 205. pIO The signal is high, which turns on the pulse power discharge switch 205 and maintains it on for a time t; at the same time, the DSP control system 4 sets the charging voltage U pgg The signal is zero until the discharge ends, at which point the DSP control system 4 outputs an on signal I to the pulse power discharge switch 205. pIO The signal is low, causing the pulse power discharge switch 205 to turn off; the DSP control system 4 adjusts the charging voltage U. pgg The signal has been restored to the set value.

[0095] Step 5 S005: Forming according to a predetermined trajectory: After the molten droplet 14 transitions to the metal substrate 9, the host computer 17 moves the electron gun to the next deposition point according to the preset trajectory, repeating steps 2 to 5 until the formation is completed according to the preset model.

[0096] Step 6 S006, Operation End: The host computer 17 sends a stop signal to the wire feeding mechanism, causing the metal wire 12 to stop feeding; the host computer 17 sends an operation end command to the DSP control system 4, and the DSP control system 4 outputs U hvgg The signal is low, causing the output of high-voltage power supply 1 to be zero; the DSP control system 4 causes U ggas When the value is zero, the air flow controller 5 is turned off; the DSP control system 4 turns on the pulse power discharge switch 205 to activate signal I. pIO When the voltage is low, the pulse power discharge switch 205 is not turned on; the DSP control system 4 sets the charging voltage signal U... pgg The value is zero, causing pulse power supply 2 to stop working; DSP control system 4 makes U dcgg The value is zero, which disables the electrostatic power supply 3.

[0097] The power supply device and forming process control method for the electron gun in space additive manufacturing provided in this application embodiment can provide a negative high voltage of -20kV to -10kV to excite and accelerate secondary electrons, melting the filament located in the electron beam energy convergence region; based on the filament end status information provided by the filament end position monitoring closed-loop control system, the pulse current source connected to the filament is controlled to operate, inputting a peak pulse current of 100A to 1000A to regulate the droplet transition rate; simultaneously, a DC voltage of -100V to -24V is provided to the electrostatic field at the tip of the electron gun to accelerate the transition of the droplet to the substrate; through the above method, the high-efficiency, high-quality and rapid manufacturing requirements of the coaxial cold cathode electron gun in the space environment can be met.

[0098] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is merely an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the system can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. Furthermore, the specific names of the functional units and modules are only for easy differentiation and are not intended to limit the scope of protection of this application.

[0099] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A power supply device for a space additive manufacturing electron gun, characterized in that, include: High-voltage power supply, pulse power supply, electrostatic field power supply, DSP control system, air flow controller, host computer; the high-voltage power supply includes a high-voltage DC power supply control circuit. The pulse power supply includes a pulse power supply discharge switch, a pulse power supply control circuit, and a charging capacitor C. 202 The electrostatic field power supply includes an electrostatic field power supply control circuit. The negative terminal of the high-voltage power supply is connected to the annular cathode, and the positive terminal of the high-voltage power supply is connected to the metal substrate through a beam sampling resistor; the negative terminal of the pulse power supply is connected to the metal wire disc support, and the positive terminal of the pulse power supply is grounded; the negative terminal of the electrostatic field power supply is connected to the electrostatic field terminal, which is disposed between the electron gun chamber and the metal substrate; the positive terminal of the electrostatic field power supply is grounded; the DSP control system is connected to the high-voltage power supply, the pulse power supply, the electrostatic field power supply, the gas flow controller, and the host computer; the gas flow controller is connected to the electron gun chamber. The DSP control system is used to: receive the start command from the host computer; control the output voltage of the high-voltage power supply to adjust the beam current in the electron beam energy focusing region; control the output pulse current of the pulse power supply to regulate the droplet transition rate; control the output voltage of the electrostatic field power supply to accelerate the transition of the droplet to the substrate; and control the gas flow rate output by the gas flow controller to adjust the beam current. The host computer receives the additive manufacturing start command and transmits the operation start command to the DSP control system. The DSP control system then executes the operation based on the high-voltage given signal U. hvg With high voltage feedback signal U hvf Perform PID control and output U hvgg The signal is sent to the high-voltage DC power supply control circuit to make the working voltage of the ring cathode connected to the output terminal of the high-voltage power supply reach the set value. The DSP control system activates the pulse power discharge switch signal I. pIO When the signal is low, the pulse power discharge switch is not activated. The DSP control system uses the pulse current given signal I pg The corresponding charging voltage signal U can be obtained by consulting the current-to-voltage conversion parameter table. pgg The DSP control system transmits this information to the pulse power supply control circuit, which then controls the charging capacitor C. 202 The highest charging voltage; The DSP control system receives the electrostatic field voltage command signal U from the external circuit. dcg After digital filtering, the output U dcgg The electrostatic field power supply control circuit ensures that the voltage at the electrostatic field terminals reaches the set value.

2. The power supply device for the space additive manufacturing electron gun as described in claim 1, characterized in that, The high-voltage power supply also includes: a high-voltage power supply reverse connection protection unit, a high-voltage power supply first inverter unit, a high-voltage power supply first transformer unit, a high-voltage power supply first rectifier circuit, a high-voltage power supply second inverter unit, a high-voltage power supply second transformer unit, a high-voltage power supply second rectifier circuit, a high-voltage power supply voltage sensor, a high-voltage power supply first inverter drive circuit, a high-voltage inverter power supply control circuit, and a high-voltage power supply second inverter drive circuit. The high-voltage power supply reverse connection protection unit receives DC power as input. The high-voltage power supply reverse connection protection unit includes diode D0, diode D1, inductor L0, and capacitor C0. The anode of diode D0 is connected to the positive terminal of the DC power supply, and the cathode of diode D0 is connected to one end of inductor L0. The cathode of diode D1 is connected to the negative terminal of the DC power supply, and the anode of diode D1 is connected to one end of capacitor C0. The other end of capacitor C0 is connected to the end of inductor L0 that is not connected to diode D0. The output terminal of the high-voltage power supply reverse connection protection unit is connected to the high-voltage power supply first inverter unit, which is a full-bridge circuit composed of power switching devices; the output terminal of the high-voltage power supply first inverter unit is connected to the power transformer T of the high-voltage power supply first transformer unit. 10 The primary side of the power transformer T 10 The secondary side is connected to the input terminal of the first rectifier circuit of the high-voltage power supply; the output terminal of the first rectifier circuit of the high-voltage power supply is connected in parallel with a high-voltage power supply voltage sensor; the high-voltage power supply voltage sensor detects the output voltage signal U of the first rectifier circuit of the high-voltage power supply. f , will U f Feedback is sent to the high-voltage DC power supply control circuit; The output terminal of the first rectifier circuit of the high-voltage power supply is connected to the second inverter unit of the high-voltage power supply; the second inverter unit of the high-voltage power supply is also a full-bridge circuit composed of power switching devices, and the gate of each power switching device is connected to the second inverter drive circuit of the high-voltage power supply. The second inverter drive circuit of the high-voltage power supply receives PWM signals from the control circuit of the high-voltage inverter power supply and controls each power switching device to turn on at full frequency and full pulse width. The second rectifier circuit of the high-voltage power supply includes a high-voltage diode D. 11 D 12 D 13 D 14 The rectifier bridge and high-voltage diode D are composed of 15 D 16 D 17 D 18 The rectifier bridge consists of the high-voltage diode D. 11 D 12 D 13 D 14 The positive terminal of the rectifier bridge is connected to the high-voltage diode D. 15 D 16 D 17 D 18 The negative end of the rectifier bridge is connected; The output terminal of the second inverter unit of the high-voltage power supply is connected to the second transformer unit of the high-voltage power supply. The second transformer unit of the high-voltage power supply includes two high-voltage transformers T. 11 T 12 The high-voltage transformer T 11 T 12 The primary side of the high-voltage transformer T is connected in parallel to the output terminal of the second inverter unit of the high-voltage power supply. 11 The two ends of the secondary side are respectively connected to the high-voltage diode D. 11 D 12 D 13 D 14 The rectifier bridge is composed of the following components; the high-voltage transformer T 12 The two ends of the secondary side are respectively connected to the high-voltage diode D. 15 D 16 D 17 D 18 The rectifier bridge is composed of; The negative output terminal of the second rectifier circuit of the high-voltage power supply is connected to the ring cathode; the positive output terminal of the second rectifier circuit of the high-voltage power supply is connected to one end of the beam sampling resistor R1, and the beam sampling signal I... bf Take it from one end of the beam sampling resistor R1, and connect the other end of the beam sampling resistor R1 to the reference ground; A high-voltage power supply high-voltage sampling circuit is connected in parallel between the negative and positive output terminals of the second rectifier circuit of the high-voltage power supply. This high-voltage sampling circuit includes several voltage divider resistors and a high-voltage sampling resistor R0. The voltage divider resistors and the high-voltage sampling resistor R0 are connected in series, and a high-voltage feedback signal U is acquired at the connection points of these resistors and the high-voltage sampling resistor R0. hvf The other end of the high-voltage sampling resistor R0 is connected to the positive output terminal of the second rectifier circuit of the high-voltage power supply. The high-voltage feedback signal U hvf Feedback is sent to the DSP control system, which then uses the high-voltage given signal U... hvg With high voltage feedback signal U hvf Perform PID control and output U hvgg The signal is sent to the high-voltage DC power supply control circuit, which simultaneously receives the output voltage signal U from the first rectifier circuit of the high-voltage power supply detected by the high-voltage power supply voltage sensor. f ; The U f with U hvgg After PID regulation by the high-voltage DC power supply control circuit, the pulse width of the output PWM signal is adjusted. Then, after passing through the first inverter drive circuit of the high-voltage power supply, four PWM signals are output to the gates of each power switching device in the full-bridge circuit of the first inverter unit of the high-voltage power supply, adjusting the conduction time of the corresponding power switching devices, thereby adjusting the output voltage of the first rectifier circuit and the output voltage of the second rectifier circuit of the high-voltage power supply, and realizing the adjustment of the negative high voltage output of the high-voltage power supply to the ring cathode.

3. The power supply device for the space additive manufacturing electron gun as described in claim 1, characterized in that, The pulse power supply also includes: a pulse power supply reverse connection protection unit, a pulse power supply inverter unit, a pulse power supply transformer unit, a pulse power supply rectifier circuit, a pulse power supply discharge switch drive circuit, a pulse power supply current sensor, and a filter inductor L. 202 1. Pulse power supply inverter drive circuit; The pulse power reverse connection protection unit receives DC power as input and includes a diode D. 201 diode D 202 Inductor L 201 Capacitor C 201 diode D 201 The anode of diode D is connected to the positive terminal of the DC power supply. 201 Cathode connection inductor L 201 One end of the diode D; 202 The cathode of diode D is connected to the negative terminal of the DC power supply. 202 Anode connection capacitor C 201 One end, capacitor C 201 The other end is connected to inductor L 201 Not with diode D 201 One end of the connection; The output terminal of the pulse power reverse connection protection unit is connected to the pulse power inverter unit, which is a bridge circuit composed of power switching devices; the output terminal of the pulse power inverter unit is connected to the transformer T of the pulse power transformer unit. 20 The primary side of the transformer T 20 The two ends of the secondary side are respectively connected to diode D 21 D 22 D 23 D 24 The input terminal of the pulse power supply rectifier circuit; The negative output terminal of the pulse power rectifier circuit is connected to the filter inductor L. 202 One end, filter inductor L 202 The other end is connected in series with a pulse power current sensor and then connected to a charging capacitor C. 202 One end, the charging capacitor C 202 The other end is connected to the positive output terminal of the pulse power rectifier circuit; the positive output terminal of the pulse power rectifier circuit is also connected to a current-limiting resistor R. 201 One end, current-limiting resistor R 201 The other end is grounded; The filter inductor L 202 With charging capacitor C 202 The common point of connection is connected to the emitter of the pulse power discharge switch, which is composed of a single high-power IGBT or multiple IGBTs connected in parallel. The collector of the pulse power discharge switch is connected to the metal wire spool support. The metal wire spool support is insulated from ground. The charging capacitor C 202 A pulse power supply voltage sensor is connected in parallel across both ends. When the pulse power supply discharge switch is not turned on, the pulse power supply voltage sensor will collect the charging voltage signal U. pf Feedback is sent to the pulse power control circuit, which then transmits the charging voltage signal U given by the DSP control system. pgg with U pf Compare; If U pgg >U pf The pulse power control circuit uses the charging current signal I collected by the pulse power current sensor. pf Adjusting the PWM pulse width changes the on / off time of the power switching devices in the pulse power inverter unit after passing through the pulse power inverter drive circuit, thus affecting the charging capacitor C. 202 Perform constant current charging; if U pgg =U pf The pulse power supply control circuit uses the charging voltage signal U collected by the pulse power supply voltage sensor. pf Adjusting the PWM pulse width affects the charging capacitor C. 202 Perform constant voltage charging to charge capacitor C. 202 The stored electrical energy is stable.

4. The power supply device for the space additive manufacturing electron gun as described in claim 3, characterized in that, The DSP control system also receives the droplet morphology status signal obtained by the host computer through machine vision. When the host computer determines that the droplet can detach from the wire end and transition to the metal substrate, the host computer outputs a droplet transition enable signal to the DSP control system. The DSP control system detects and feeds back the charging voltage signal U. pf Has the set charging voltage U been reached? pgg If this is achieved, the DSP control system will issue a pulse power discharge switch on signal I. pIO The signal is transmitted to the base of the pulse power discharge switch through the pulse power discharge switch drive circuit, causing the pulse power discharge switch to conduct. During the pulse power discharge switch's on-time period, the DSP control system adjusts the charging voltage U. pgg If the signal is zero, the pulse power supply control circuit will not output a PWM signal, and the power switching devices in the pulse power supply inverter unit will not operate; at the end of the discharge, the DSP control system will set the charging voltage U... pgg The signal has been restored to the set value.

5. The power supply device for the space additive manufacturing electron gun as described in claim 1, characterized in that, The electrostatic power supply also includes: an electrostatic power supply reverse connection protection unit, an electrostatic power supply inverter unit, an electrostatic power supply transformer unit, an electrostatic power supply rectifier circuit, and an electrostatic power supply inverter drive circuit. The electrostatic field power supply reverse connection protection unit receives DC power as input and includes a diode D. 301 diode D 302 Inductor L 301 Capacitor C 301 diode D 301 The anode of diode D is connected to the positive terminal of the DC power supply. 301 Cathode connection inductor L 301 One end of the diode D; 302 The cathode of diode D is connected to the negative terminal of the DC power supply. 302 Anode connection capacitor C 301 One end, capacitor C 301 The other end is connected to inductor L 301 Not with diode D 301 One end of the connection; The output terminal of the electrostatic field power supply reverse connection protection unit is connected to the electrostatic field power supply inverter unit, which is a bridge circuit composed of power switching devices; the output terminal of the electrostatic field power supply inverter unit is connected to the transformer T of the electrostatic field power supply transformer unit. 30 The primary side of the transformer T 30 The two ends of the secondary side are respectively connected to diode D 31 D 32 D 33 D 34 The input terminal of the electrostatic field power supply rectifier circuit; The positive output terminal of the electrostatic field power supply rectifier circuit is grounded; the negative output terminal of the electrostatic field power supply rectifier circuit is connected to the filter inductor L. 302 One end, filter inductor L 302 The other end is connected to the filter inductor L 303 One end, filter inductor L 303 The other end is connected to a current-limiting resistor R. 301 Connected to the electrostatic field terminal; the filter inductor L 302 With the filter inductor L 303 The common connection point is connected to the filter capacitor C. 302 One end, filter capacitor C 302 The other end is grounded; The filter capacitor C 302 An electrostatic field power supply voltage sensor is connected in parallel across both ends of the device. The electrostatic field power supply voltage sensor collects the electrostatic field voltage signal U. dcf Transmitted to the electrostatic field power supply control circuit; The electrostatic field power supply control circuit will use the U given by the DSP control system dcgg with U dcf PID control is performed to adjust the output PWM pulse width, and the on / off time of the power switching devices in the electrostatic field power inverter unit is controlled by the electrostatic field power inverter drive circuit, thereby maintaining a stable voltage at the electrostatic field terminals; the U dcgg It is the electrostatic field voltage given signal U from the external circuit. dcg The signal obtained after digital filtering.

6. A method for controlling the forming process of a space additive manufacturing electron gun, characterized in that, The power supply device is based on the space additive manufacturing electron gun according to any one of claims 1 to 5; The method for controlling the forming process of the space additive manufacturing electron gun includes: The host computer receives the additive manufacturing start command and transmits the operation start command to the DSP control system. The DSP control system then executes the operation based on the high-voltage given signal U. hvg With high voltage feedback signal U hvf Perform PID control and output U hvgg The signal is sent to the high-voltage DC power supply control circuit to make the working voltage of the ring cathode connected to the output terminal of the high-voltage power supply reach the set value. The DSP control system is based on the beam current given I bg and beam feedback I bf PID control is performed to convert the airflow into a setpoint signal U. ggas The signal is transmitted to the air flow controller, which then transmits the air flow signal U. gas The gas is transmitted to the gas flow meter, which then transmits the working gas through the gas guide tube into the electron gun chamber to adjust the beam size. The DSP control system activates the pulse power discharge switch signal I. pIO When the signal is low, the pulse power supply discharge switch is not turned on; the DSP control system responds to the pulse current given signal I. pg The corresponding charging voltage signal U can be obtained by consulting the current-to-voltage conversion parameter table. pgg The DSP control system transmits this information to the pulse power supply control circuit, which then controls the charging capacitor C. 202 The highest charging voltage; The DSP control system receives the electrostatic field voltage command signal U from the external circuit. dcg After digital filtering, the output U dcgg The electrostatic field power supply control circuit ensures that the voltage at the electrostatic field terminals reaches the set value. The host computer controls the wire feeding mechanism to feed the metal wire at a preset speed. The metal wire is heated and melted at the convergence point of the annular electron beam. The molten metal forms droplets under the action of surface tension. The droplet morphology status signal obtained by machine vision is transmitted to the host computer. If the host computer determines that the three-dimensional size of the molten droplet has reached the preset value, it outputs a droplet transition enable signal to the DSP control system. The DSP control system detects the feedback charging voltage signal U. pf Has the set charging voltage U been reached? pgg ; If U pf When the set value is reached, the DSP control system outputs a pulse power discharge switch on signal I. pIO The signal is high, turning on the pulse power supply discharge switch; simultaneously, the DSP control system increases the charging voltage U. pgg The signal remains zero until the discharge ends, at which point the DSP control system outputs a pulse power discharge switch on signal I. pIO The signal is low, causing the pulse power supply discharge switch to turn off; the DSP control system adjusts the charging voltage U. pgg The signal has been restored to the set value; After the molten droplet transitions to the metal substrate, the host computer moves the electron gun to the next deposition point according to the preset trajectory, repeating the above steps until the shape is completed according to the preset model.

7. The method for controlling the forming process of a space additive manufacturing electron gun as described in claim 6, characterized in that, Also includes: The host computer sends a stop signal to the wire feeding mechanism, stopping the wire feeding. The host computer also sends a run-end command to the DSP control system, which outputs a U... hvgg When the signal is low, the output of the high-voltage power supply is zero. DSP control system enables U ggas When the value is zero, the gas flow controller is turned off, and the DSP control system activates the pulse power discharge switch signal I. pIO When the voltage is low, the pulse power supply discharge switch is not turned on, and the DSP control system makes the charging voltage signal U... pgg The value is zero, causing the pulse power supply to stop working. The DSP control system then makes U... dcgg The value is zero, which disables the electrostatic power supply.

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