Load device for pulse power supply test

Abstract

The present invention discloses a load device for testing a pulse power supply, which includes a discharge electrode, a conductive liquid tank, a driving mechanism, a refrigeration mechanism, a voltage sensor and a current sensor; the discharge electrode is electrically connected to the output end of the pulse power supply according to polarity, the voltage sensor is connected in parallel with the discharge electrode according to polarity, and the current sensor is connected in series with the discharge electrode according to the current direction; the conductive liquid tank carries conductive liquid, and the refrigeration mechanism is used to cool the conductive liquid in the conductive liquid tank; the driving mechanism drives the discharge electrode to move to control whether the discharge electrode is immersed in the conductive liquid and the depth of immersion in the conductive liquid. The present invention mainly solves the problem of how to provide a load device that can withstand DC high voltage, large current pulse impact and long-term high power output test; it can withstand DC high voltage, large current pulse impact and long-term high power output test, has high durability, and has lower cost than resistive load and electronic load, and is suitable for popularization and application.

Description

Technical Field

[0001] The invention relates to the technical field of power supply loads, in particular to a load device for testing a pulse power supply. Background Art

[0002] The pulse power supply used for plasma discharge in the vacuum coating industry has the characteristics of high DC voltage (super kilovolts), large pulse impact current (super kiloamperes) and high power (hundreds of kilowatts). Ordinary DC electronic loads cannot withstand the high-voltage and high-current impact and long-term high-power output test of this type of pulse power supply.

[0003] At present, there are two solutions for the load device for output testing of this type of pulse power supply:

[0004] 1. Resistive load: Use power resistors in series and parallel to achieve the required electrical parameter requirements; although the cost of the resistive load solution is low, the resistive load device occupies a large space, has fixed electrical parameters, and is not suitable for wide range measurements.

[0005] 2. Electronic load: The electronic load is constructed using power transistors. Through inverter conversion, the electric energy consumed in the output test can be fed back to the power grid. However, the electronic load device cannot withstand the pulse impact of ultra-kilovolt DC voltage and kiloampere current, and the impedance characteristics of the electronic load device are different from those of vacuum plasma, so it is impossible to test the special pulse power supply in the vacuum coating industry.

[0006] In summary, how to provide a load device with low cost, high durability, and the ability to withstand high DC voltage, high current pulse impact, and long-term high power output testing has become an urgent problem to be solved. Summary of the invention

[0007] The object of the present invention is to provide a load device for testing a pulse power supply, which can withstand direct current high voltage, large current pulse impact and long-term high power output test and has low cost.

[0008] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a load device for testing a pulse power supply, comprising a discharge electrode, a conductive liquid tank, a driving mechanism, a cooling mechanism, a voltage sensor and a current sensor; the discharge electrode is electrically connected to the output end of the pulse power supply according to polarity, the voltage sensor is connected in parallel with the discharge electrode according to polarity, and the current sensor is connected in series with the discharge electrode according to the current direction; the conductive liquid tank carries conductive liquid, and the cooling mechanism is used to cool the conductive liquid in the conductive liquid tank; the driving mechanism drives the discharge electrode to move to control whether the discharge electrode is immersed in the conductive liquid and the depth of the immersion in the conductive liquid.

[0009] In the above technical solution, the driving mechanism includes an electric cylinder, an electrode bracket and an insulating clamp; the discharge electrode is fixed to the electrode bracket through the insulating clamp, and the electrode bracket is fixed to the push rod of the electric cylinder.

[0010] In the above technical solution, the load device for testing the pulse power supply also includes a short-circuit mechanism; the short-circuit mechanism includes a short-circuit electrode, an electromagnet and a contactor; one end of the contactor is electrically connected to one of the discharge electrodes, and the other end of the contactor is electrically connected to the short-circuit electrode; the electromagnet magnetically couples the short-circuit electrode to contact the other discharge electrode.

[0011] In the above technical solution, the load device for pulse power supply testing further includes a high-concentration conductive liquid channel for adding high-concentration conductive liquid into the conductive liquid tank.

[0012] In the above technical solution, the load device for testing a pulse power supply further includes a solvent channel for adding a solvent into the conductive liquid tank.

[0013] In the above technical solution, the load device for pulse power supply testing also includes a density sensor for measuring the density of the conductive liquid in the conductive liquid box.

[0014] In the above technical solution, the load device for pulse power supply testing also includes a liquid level sensor for measuring the liquid level of the conductive liquid in the conductive liquid tank.

[0015] In the above technical solution, the load device for testing the pulse power supply further includes a temperature sensor for measuring the temperature of the conductive liquid in the conductive liquid box.

[0016] In the above technical solution, the refrigeration mechanism includes a compressor, a condenser, a throttling device and an evaporator tube. The compressor, the condenser, the throttling device and the evaporator tube are circulated and connected in sequence along the flow direction of the refrigerant; the evaporator tube is connected to the conductive liquid tank and immersed in the conductive liquid, and the evaporator tube is coiled in the conductive liquid tank.

[0017] In the above technical solution, the evaporation tube is wrapped with a Teflon coating.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] 1. This type of load device for pulse power supply testing forms a circuit through a pulse power supply, a discharge electrode and a conductive liquid, with the conductive liquid providing load impedance, and drives the discharge electrode to move through a driving mechanism to control whether the discharge electrode is immersed in the conductive liquid and the depth of the immersion in the conductive liquid, thereby simulating various load conditions of the pulse power supply for plasma discharge in the vacuum coating industry, and then completing the pulse power supply test. It can withstand high DC voltage, high current pulse impact and long-term high-power output test, has high durability, and lower cost than resistive load and electronic load, and is suitable for promotion and application.

[0020] 2. This type of load device for pulse power supply testing is used to cool the conductive liquid in the conductive liquid tank through a refrigeration mechanism, so that the temperature of the conductive liquid is maintained constant, it is not easy to overheat and evaporate, it has high stability, and the load impedance is not easy to fluctuate. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a system schematic diagram of the present invention.

[0022] Figure 2 It is a structural schematic diagram of the evaporation tube in the present invention.

[0023] Figure 3 Schematic diagram of system control of the present invention.

[0024] The accompanying drawings are marked as follows: 1. discharge electrode; 2. conductive liquid tank; 3. driving mechanism; 31. electric cylinder; 32. electric cylinder bracket; 33. electrode bracket; 4. refrigeration mechanism; 41. compressor; 42. condenser; 43. throttling device; 44. evaporation tube; 441. Teflon coating; 5. short-circuit mechanism; 51. short-circuit electrode; 52. electromagnet; 53. contactor; 54. fixed beam; 61. high-concentration conductive liquid channel; 62. solvent channel; 63. liquid discharge channel; 71. density sensor; 72. liquid level sensor; 73. temperature sensor; 81. voltage sensor; 82. current sensor. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] See also Figure 1-Figure 3 A load device for pulse power supply testing includes a discharge electrode 1, a conductive liquid box 2, a drive mechanism 3, a cooling mechanism 4, a voltage sensor 81 and a current sensor 82.

[0027] At the same time, the load device for pulse power supply testing also includes a main control, which is an embedded chip, a programmable controller (PLC) or an industrial computer, and the main control has at least a number of general input / output interfaces and analog input / output interfaces.

[0028] In this embodiment, the conductive liquid box 2 is a metal box, which has an outer box and an inner box. The inner box is a square metal box with a volume of 1m³. Considering the corrosiveness of the conductive liquid, the load-bearing capacity and heat resistance of the inner box, 316 stainless steel is used for welding as the inner box, and Teflon coating is sprayed on the inner wall and bottom wall of the inner box. The outer wall of the inner box is wrapped with an insulating layer, for example, the outer wall of the inner box is wrapped with engineering plastics or rubber to insulate the outer box and the inner box, and the inner box is fixed in the outer box with a metal bracket. In other possible embodiments, engineering plastics with good heat resistance are used as the inner box, and then the inner box and the outer box are directly fixed, which can also insulate the outer box and the inner box; the outer box is grounded so that the electric energy applied to the outer box can be introduced into the ground when leakage occurs, further improving the safety of use.

[0029] The conductive liquid box 2 contains a conductive liquid. In this embodiment, the solvent of the conductive liquid is pure water and the solute is sodium chloride. The conductive liquid has conductive properties and also has impedance. When the power supply circuit is connected, it can provide impedance for the circuit, thereby serving as a load for power supply testing.

[0030] The discharge electrode 1 is a long strip of 316 stainless steel. To slow down the corrosion of the discharge electrode 1, its dimensions are 1000 mm long, 20 mm wide, and 10 mm thick. Its bottom is turned into an angular shape to reduce the splashing of liquid when the discharge electrode 1 is inserted into the liquid. There are two discharge electrodes 1, corresponding to the positive and negative poles respectively, and the specifications of the two discharge electrodes 1 are the same.

[0031] The discharge electrode 1 is electrically connected to the output end of the pulse power supply according to polarity. Specifically, the two discharge electrodes 1 are electrically connected to the positive and negative output ends of the pulse power supply through a large current cable, so that the two discharge electrodes 1 correspond to the positive and negative poles respectively. The voltage sensor 81 is connected in parallel with the discharge electrode 1 according to polarity, that is, the voltage sensor 81 is a DC voltage sensor, or a multifunctional voltage sensor is used and set to a DC voltage detection gear. The positive and negative input ends of the voltage sensor 81 are connected to the two discharge electrodes 1 through a large current cable according to polarity. The sampling frequency of the voltage sensor 81 is at the MHz level, which can quickly sample the actual voltage value of the pulse current and meet the needs of short-circuit testing. The current sensor 82 is connected in series with the discharge electrode 1 according to the current direction, that is, the current sensor 82 is a DC current sensor, or a multifunctional current sensor is used and set to a DC current detection gear. The current sensor 82 is connected in series with the discharge electrode 1 corresponding to the negative pole through a large current cable. The sampling frequency of the current sensor 82 is at the MHz level, which can quickly sample the actual current value of the pulse current and meet the needs of short-circuit testing. The signal output terminals of the voltage sensor 81 and the current sensor 82 are respectively connected to the analog input / output interface signal of the main control to feed back the voltage and current signals to the main control to complete the pulse power supply test.

[0032] The driving mechanism 3 drives the discharge electrode 1 to move so as to control whether the discharge electrode 1 is immersed in the conductive liquid and the depth of immersion in the conductive liquid; specifically, the driving mechanism 3 includes an electric cylinder 31, an electric cylinder bracket 32, an electrode bracket 33 and an insulating clamp; the electric cylinder bracket 32 ​​is a metal bracket, which is straddled on the conductive liquid box 2, that is, the electric cylinder bracket 32 ​​includes two feet and a beam arm, the two feet are respectively vertically fixed on the two opposite walls of the outer box of the conductive liquid box 2, the beam arm is straddled and fixed on the two feet, and the beam arm provides a fixed foundation for the electric cylinder 31; the electric cylinder 31 is an electric cylinder driven by a servo motor, and its push rod can perform precise telescopic movement, the body of the electric cylinder 31 is fixed on the beam arm of the electric cylinder bracket 32, the push rod of the electric cylinder 31 is vertically downwardly arranged and passes through the beam arm of the electric cylinder bracket 32, and the control end of the servo motor of the electric cylinder 31 is connected to the general input / output pin of the main control; the insulating clamp block is a clamp block made of engineering plastic, and the insulating clamp block A clamping groove is provided, and the shape of the clamping groove matches the discharge electrode 1, that is, the discharge electrode 1 can be inserted into the clamping groove of the insulating clamping block; the electrode bracket 33 is a metal arm, and two insulating clamping blocks are provided. The two insulating clamping blocks are respectively fixed at both ends of the electrode bracket 33, so that the two discharge electrodes 1 have a certain distance; the discharge electrode 1 is fixed on the electrode bracket 33 through the insulating clamping block, and the electrode bracket 33 is fixed on the push rod of the electric cylinder 31. Specifically, the electrode bracket 33 is horizontally fixed to the end of the push rod of the electric cylinder 31; after the assembly is completed, the electric cylinder 31 can link the two discharge electrodes 1 to rise and fall, and when the conductive liquid box 2 carries the conductive liquid, the electric cylinder 31 can link the two discharge electrodes 1 to control whether the two discharge electrodes 1 are immersed in the conductive liquid and the depth of the two discharge electrodes 1 immersed in the conductive liquid. The fixed heights of the two discharge electrodes 1 are the same, so that the two discharge electrodes 1 are immersed in or leave the conductive liquid at the same time, and the depths of the two discharge electrodes 1 immersed in the conductive liquid are the same.

[0033] The present invention utilizes the resistance law R=ρL / S, where: R is the resistance value, ρ is the resistivity of the conductor, L is the length of the conductor, and S is the cross-sectional area of ​​the conductor; that is, the resistance value is equal to the resistivity of the conductor multiplied by the length of the conductor divided by the cross-sectional area of ​​the conductor; in the present invention, the load is composed of two discharge electrodes 1 and a conductive liquid, and the resistivity, length and cross-sectional area of ​​the discharge electrode 1 are fixed, so the factors affecting the load impedance are the resistivity of the conductive liquid and the contact area between the discharge electrode 1 and the conductive liquid. By adjusting the ion concentration of the conductive liquid, the resistivity of the conductive liquid can be limited to a certain range. At this time, only the contact area between the discharge electrode 1 and the conductive liquid is a variable, and the electric cylinder 31 drives the discharge electrode 1 to move up and down to change the contact area between the discharge electrode 1 and the conductive liquid, thereby changing the load impedance. The voltage value between the two discharge electrodes 1 is sampled by the voltage sensor 81, the current value flowing through the discharge electrode 1 is sampled by the current sensor 82, and the stroke of the discharge electrode 1 is sampled by the sensor of the electric cylinder 31, and the feedback is sent to the main control for closed-loop control, so that the impedance value of the load device for pulse power supply test can be fine-tuned by adjusting the stroke of the discharge electrode 1. By continuously controlling the movement speed and stroke of the discharge electrode 1 by the electric cylinder 31, the contact area between the discharge electrode 1 and the conductive liquid is changed linearly or nonlinearly, and various impedance waveforms such as triangle, trapezoid, sine wave and pulse wave can be simulated within a certain range.

[0034] When performing a pulse power supply test, the push rod of the electric cylinder 31 retracts, causing the discharge electrode 1 to leave the conductive liquid, and the pulse power supply to be tested is turned on to apply electrical energy to the discharge electrode 1; the push rod of the electric cylinder 31 extends, causing the discharge electrode 1 to enter the conductive liquid, thereby connecting the circuit composed of the pulse power supply, the discharge electrode 1 and the conductive liquid, and starting the pulse power supply test. The movement speed and stroke of the discharge electrode 1 are continuously controlled by the electric cylinder 31, thereby linearly or nonlinearly changing the contact area between the discharge electrode 1 and the conductive liquid, so that various impedance waveforms such as triangles, trapezoids, sine waves and pulse waves can be simulated within a certain range, thereby simulating various load conditions of the pulse power supply for plasma discharge in the vacuum coating industry; the main control continuously records the voltage value continuously fed back by the voltage sensor 81 and the current value continuously fed back by the current sensor 82, and generates a chart to obtain the electrical parameters of the pulse power supply, thereby completing the pulse power supply test.

[0035] The refrigeration mechanism 4 is used to cool the conductive liquid in the conductive liquid tank 2; the refrigeration mechanism 4 includes a compressor 41, a condenser 42, a throttling device 43 and an evaporation tube 44, and the compressor 41, the condenser 42, the throttling device 43 and the evaporation tube 44 are circulated and connected in sequence along the flow direction of the refrigerant; specifically, the compressor 41, the condenser 42, the throttling device 43 and the evaporation tube 44 are connected in sequence through pipelines, and the evaporation tube 44 is also connected to the input end of the compressor 41 through the pipeline, thereby forming a refrigerant circulation loop; in this embodiment, the evaporation tube 44, the pipeline in the condenser 42, and the pipeline connecting the compressor 41, the condenser 42, the throttling device 43 and the evaporation tube 44 are all copper tubes; the evaporation tube 44 is connected to the conductive liquid tank 2 and immersed in the conductive liquid In the body, that is, the evaporation tube 44 passes through the outer box and the inner box of the conductive liquid box 2 until it enters the inner box cavity of the conductive liquid box 2, and the gaps between the evaporation tube 44 and the outer box and the inner box of the conductive liquid box 2 are filled with heat-resistant sealant respectively; the evaporation tube 44 is coiled in the conductive liquid box 2. In this embodiment, the evaporation tube 44 is coiled in the conductive liquid box 2 in a spiral shape to increase the contact area between the evaporation tube 44 and the conductive liquid and improve the cooling effect; the refrigerant is compressed into a high-temperature and high-pressure gas state by the compressor 41, and then condensed into a medium-temperature and high-pressure liquid state in the condenser 42 and releases heat, and then expanded into a low-temperature and low-pressure liquid state in the throttling device 43, and finally absorbs heat in the evaporation tube 44 and is converted into a gas state. After the refrigerant flows back to the compressor 41, a refrigeration cycle is completed. The control signal interface of the compressor 41 is connected to the general input / output interface signal of the main control, so that the main control can control the operating power of the compressor 41, thereby adjusting the cooling capacity of the refrigeration mechanism 4.

[0036] When the power supply test is performed, the conductive liquid in the conductive liquid tank 2 is charged and generates a large amount of heat. It is necessary to ensure that there is good heat exchange performance between the evaporation tube 44 and the conductive liquid in order to cool the conductive liquid. At the same time, it is also necessary to ensure that there is insulation between the evaporation tube 44 and the conductive liquid to avoid damaging the refrigeration mechanism 4. Based on this consideration, the evaporation tube 44 is wrapped with a Teflon coating 441, that is, a layer of Teflon coating 441 is sprayed on the outside of the evaporation tube 44; the evaporation tube 44 is wrapped with the Teflon coating 441, so that the evaporation tube 44 has good insulation performance, can withstand a voltage of 5kV, and maintain good thermal conductivity.

[0037] The load device for testing the pulse power supply also includes a short-circuit mechanism 5 so as to perform a short-circuit test on the pulse power supply; the short-circuit mechanism 5 includes a short-circuit electrode 51, an electromagnet 52 and a contactor 53, wherein the short-circuit electrode 51 is a workpiece made of 316 stainless steel, and the lower part of the short-circuit electrode 51 is bent to form a bent portion; a fixed beam 54 is provided on the outer box of the conductive liquid box 2, and the fixed beam 54 is straddled on two opposite walls of the outer box of the conductive liquid box 2, and is located below the bracket of the electric cylinder 31, and the fixed beam 54 and the electric cylinder bracket 32 ​​are perpendicular to each other; the short-circuit electrode 51 is pivotally connected to the fixed beam 54 through a pivot frame made of engineering plastic material; the electromagnet 52 is also fixed on the fixed beam 54, and after the electromagnet 52 is energized, it can adsorb the short-circuit electrode 51, so that the short-circuit electrode 51 swings; in this embodiment, the universal input / output interface of the main control directly powers the electromagnet 52; the contactor 53 is a DC contactor, one end of the contactor 53 is electrically connected to one of the discharge electrodes 1, in this embodiment, this end of the contactor 53 is electrically connected to the discharge electrode 1 of the corresponding positive pole, and the other end of the contactor 53 is electrically connected to the short-circuit electrode 51; the control end of the contactor 53 is connected to the universal input / output interface signal of the main control; the electromagnet 52 magnetically couples the short-circuit electrode 51 to contact with another discharge electrode 1, that is, after the electromagnet 52 is energized, it can absorb the short-circuit electrode 51, so that the short-circuit electrode 51 swings toward the discharge electrode 1 of the corresponding negative pole, and then the bent portion of the short-circuit electrode 51 contacts with the discharge electrode 1 of the corresponding negative pole.

[0038] When performing a short-circuit test, the push rod of the electric cylinder 31 extends to allow the discharge electrode 1 to enter the conductive liquid to a certain depth, thereby obtaining a certain load impedance; the contactor 53 is closed in advance to electrically connect the short-circuit electrode 51 to the discharge electrode 1 of the corresponding positive electrode; then the universal input / output interface of the main control directly supplies power to the electromagnet 52, and then the power is instantly cut off to allow the electromagnet 52 to operate for an instant. During this instant, the electromagnet 52 absorbs the short-circuit electrode 51, so that the bent portion of the short-circuit electrode 51 contacts the discharge electrode 1 of the corresponding negative electrode for an instant and then separates. When the bent portion of the short-circuit electrode 51 contacts the discharge electrode 1 of the corresponding negative electrode, the discharge electrodes 1 of the corresponding positive and negative electrodes are short-circuited, thereby simulating the electrical condition of a target short circuit in a vacuum furnace in the vacuum coating industry. The main control records the voltage value continuously fed back by the voltage sensor 81 and the current value continuously fed back by the current sensor 82 at this instant, and generates a chart to record the electrical parameters of the pulse power supply under the short-circuit condition. In this way, the short-circuit test of the pulse power supply can be completed.

[0039] The load device for testing the pulse power supply also includes a high-concentration conductive liquid channel 61 for adding high-concentration conductive liquid to the conductive liquid tank 2, a solvent channel 62 for adding solvent to the conductive liquid tank 2, a density sensor 71 for measuring the density of the conductive liquid in the conductive liquid tank 2, a liquid level sensor 72 for measuring the liquid level of the conductive liquid in the conductive liquid tank 2, and a discharge channel 63 for releasing the conductive liquid in the conductive liquid tank 2. The high-concentration conductive liquid channel 61 is a plastic pipe, one end of which is connected to the inner box of the conductive liquid tank 2. A solenoid valve is provided on the high-concentration conductive liquid channel 61, and the solenoid valve is connected to the general input / output interface signal of the main control. The staff configures a high-concentration conductive liquid of a constant concentration and stores it in a high-concentration conductive liquid storage tank. A liquid pump is provided in the high-concentration conductive liquid storage tank. The other end of the high-concentration conductive liquid channel 61 is connected to the output end of the liquid pump. The liquid pump provides pressure for the high-concentration conductive liquid. After the solenoid valve is opened, the high-concentration conductive liquid can enter the conductive liquid tank 2, thereby increasing the concentration of the conductive liquid. The solvent channel 62 is a plastic pipe, one end of which is connected to the inner box of the conductive liquid box 2. A solenoid valve is provided on the solvent channel 62, and the solenoid valve is connected to the general input / output interface signal of the main control. The staff stores pure water in the solvent storage tank, and a liquid pump is provided in the solvent storage tank. The other end of the solvent channel 62 is connected to the output end of the liquid pump, and the liquid pump provides pressure for the pure water. After the solenoid valve is opened, the pure water can enter the conductive liquid box 2, thereby reducing the concentration of the conductive liquid. The body of the density sensor 71 is fixed on the outer box of the conductive liquid box 2, and the probe of the density sensor 71 is insulated, such as wrapped in plastic or rubber. The probe of the density sensor 71 extends into the conductive liquid in the conductive liquid box 2 to detect the density of the conductive liquid in the conductive liquid box 2; the signal output end of the density sensor 71 is connected to the analog input / output interface signal of the main control. The liquid level sensor 72 is an ultrasonic liquid level sensor, the body of which is fixed on the outer box of the conductive liquid tank 2. The probe of the liquid level sensor 72 extends into the inner box of the conductive liquid tank 2 and is located above the conductive liquid to detect the liquid level of the conductive liquid in the conductive liquid tank 2. The signal output end of the liquid level sensor 72 is connected to the analog input / output interface signal of the main control. The discharge channel 63 is a plastic pipe, one end of which is connected to the inner box of the conductive liquid tank 2, and the other end of the discharge channel 63 is connected to the return water channel to recover the conductive liquid. In this embodiment, two discharge channels 63 are provided, one of which is provided with a solenoid valve, which is connected to the universal input / output interface signal of the main control so that the discharge channel 63 can be controlled by the main control to discharge, and the other discharge channel 63 is provided with a manual valve so that the staff can manually discharge.The main control calculates the current conductive liquid concentration of the conductive liquid tank 2 according to the signal fed back by the density sensor 71; if the concentration is lower than the set range, the solenoid valve of the high-concentration conductive liquid channel 61 is opened to add high-concentration conductive liquid to the conductive liquid tank 2 until the concentration of the conductive liquid returns to the set range; if the concentration is higher than the set range, the solenoid valve of the solvent channel 62 is opened to add pure water to the conductive liquid tank 2 until the concentration of the conductive liquid returns to the set range. The main control calculates the current conductive liquid level of the conductive liquid tank 2 according to the signal fed back by the liquid level sensor 72; if the liquid level is lower than the set range, the solenoid valves of the high-concentration conductive liquid channel 61 and the solvent channel 62 are opened to add conductive liquid to the conductive liquid tank 2 until the conductive liquid level returns to the set range; if the liquid level is higher than the set range, the solenoid valve of the liquid discharge channel 63 is opened to release the conductive liquid in the conductive liquid tank 2 until the conductive liquid level returns to the set range.

[0040] This load device for testing a pulse power supply also includes a temperature sensor 73 for measuring the temperature of the conductive liquid in the conductive liquid box 2. The body of the temperature sensor 73 is fixed on the outer box of the conductive liquid box 2. The probe of the temperature sensor 73 is wrapped with plastic with good thermal conductivity and inserted into the conductive liquid in the conductive liquid box 2, so that the temperature sensor 73 can measure the temperature of the conductive liquid; the temperature sensor 73 is connected to the analog input / output interface signal of the main control, so as to feed back the temperature of the conductive liquid in the conductive liquid box 2 to the main control, provide a reference for the main control to adjust the operating power of the compressor 41 in the refrigeration mechanism 4, and realize closed-loop control of the temperature of the conductive liquid.

[0041] This load device for testing pulse power supplies forms a circuit through a pulse power supply, a discharge electrode 1, and a conductive liquid, and uses the conductive liquid to provide load impedance. The discharge electrode 1 is driven to move by a driving mechanism 3 to control whether the discharge electrode 1 is immersed in the conductive liquid and the depth of the immersion in the conductive liquid, thereby simulating various load conditions of the pulse power supply for plasma discharge in the vacuum coating industry, and then completing the pulse power supply test. It can withstand high DC voltage, high current pulse impact, and long-term high-power output testing, has high durability, and is lower in cost than resistive loads and electronic loads, and is suitable for promotion and application. Moreover, the refrigeration mechanism 4 is used to cool the conductive liquid in the conductive liquid tank 2, so that the temperature of the conductive liquid is maintained constant, and it is not easy to overheat and evaporate. It has high stability and the load impedance is not easy to fluctuate.

[0042] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A load device for pulse power supply testing, characterized in that: It includes a discharge electrode, a conductive liquid tank, a driving mechanism, a refrigeration mechanism, a voltage sensor and a current sensor; The discharge electrode is electrically connected to the output end of the pulse power supply according to polarity, the voltage sensor is connected in parallel with the discharge electrode according to polarity, and the current sensor is connected in series with the discharge electrode according to current direction; The conductive liquid tank contains conductive liquid, and the refrigeration mechanism is used to cool the conductive liquid in the conductive liquid tank; The driving mechanism drives the discharge electrode to move so as to control whether the discharge electrode is immersed in the conductive liquid and the depth of the discharge electrode immersed in the conductive liquid; Also includes a short-circuit mechanism; The short-circuit mechanism includes a short-circuit electrode, an electromagnet and a contactor; one end of the contactor is electrically connected to one of the discharge electrodes, and the other end of the contactor is electrically connected to the short-circuit electrode; the electromagnet magnetically couples the short-circuit electrode to contact the other discharge electrode.

2. The load device for pulse power supply testing according to claim 1, characterized in that: The driving mechanism comprises an electric cylinder, an electrode support and an insulating clamp; the discharge electrode is fixed on the electrode support through the insulating clamp, and the electrode support is fixed on the push rod of the electric cylinder.

3. The load device for pulse power supply testing according to claim 1, characterized in that: Also included is a high-concentration conductive liquid channel for adding high-concentration conductive liquid into the conductive liquid tank.

4. The load device for pulse power supply testing according to claim 1 or 3, characterized in that: Also included is a solvent channel for adding solvent to the conductive liquid tank.

5. The load device for pulse power supply testing according to claim 1, characterized in that: Also included is a density sensor for measuring the density of the conductive liquid in the conductive liquid tank.

6. The load device for pulse power supply testing according to claim 1, characterized in that: Also included is a liquid level sensor for measuring the liquid level of the conductive liquid in the conductive liquid tank.

7. The load device for pulse power supply testing according to claim 1, characterized in that: Also included is a temperature sensor for measuring the temperature of the conductive liquid in the conductive liquid tank.

8. The load device for pulse power supply testing according to claim 1, characterized in that: The refrigeration mechanism comprises a compressor, a condenser, a throttling device and an evaporating tube, wherein the compressor, the condenser, the throttling device and the evaporating tube are circulated and connected in sequence along the flow direction of the refrigerant; The evaporation tube is connected to the conductive liquid box and immersed in the conductive liquid, and the evaporation tube is coiled in the conductive liquid box.

9. The load device for pulse power supply testing according to claim 8, characterized in that: The evaporation tube is wrapped with a Teflon coating.

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