System and method for testing withstand voltage performance of high-voltage cable of ion thruster

Abstract

The invention relates to the technical field of spacecraft propulsion, in particular to an ion thruster high-voltage cable withstand voltage performance test system and method, and the system comprises a vacuum device, an ion thruster, a high-voltage cable, a DC power supply, a stepping motor, and a discharge monitoring system. Wherein the vacuum equipment adopts a flange binding post to realize power supply connection inside and outside the equipment; the ion thruster is mounted in the vacuum equipment in an insulated mounting manner; the direct-current power supply is a variable voltage-stabilizing direct-current power supply and is mounted outside the vacuum equipment; the high-voltage cable comprises a first cable and a second cable; the middle area of the first cable is fixed on the stepping motor in an insulated mounting manner; and the discharge monitoring system is arranged in the vacuum equipment. According to the invention, safe and reliable loading of high-voltage cable power supply is realized in a manner of loading the screen grid voltage in a stepped manner, and the risk of misjudgment of the power supply performance of the high-voltage cable caused by ion beam current flickering in the high-voltage loading process is solved.

Description

Technical Field

[0001] This application relates to the field of spacecraft propulsion technology, and more specifically, to a test system and method for the withstand voltage performance of high-voltage cables for ion thrusters. Background Technology

[0002] Ion electric propulsion technology, with ion thrusters at its core, has outstanding advantages such as high specific impulse, long lifespan, and precise adjustable thrust, and is widely used in spacecraft attitude control, orbital transfer, and position maintenance missions.

[0003] Due to its unique working principle and structural form, the highest operating voltage of an ion thruster during operation typically reaches thousands of volts. This places high demands on the insulation characteristics of the ion thruster itself, as well as stringent requirements on the voltage withstand performance of its high-voltage power supply cable. As the power carrier between the ion thruster and the power supply unit, the high voltage withstand performance is fundamental to the normal operation of the ion thruster. Therefore, the assessment and verification of the voltage withstand performance of high-voltage cables is a fundamental project in the verification of high-voltage electrical performance in aerospace electric propulsion, and it often runs throughout the entire process of high-voltage cable power supply performance testing.

[0004] Currently, the voltage withstand performance verification of high-voltage cables used in ion thrusters is mostly conducted according to their design specifications. Although there are numerous verification items and complex testing methods, the testing conditions and methods for voltage withstand performance testing are relatively simple and do not fully consider the characteristics and modes of ion thruster space applications. The verification methods and their rationality need further improvement, and there is a significant difference between the actual verification results and application requirements. Therefore, it is necessary to further improve the methods for verifying the voltage withstand performance of electric propulsion high-voltage cables and the corresponding test systems to provide support for the safe and reliable on-orbit application of ion thrusters. Summary of the Invention

[0005] This application provides a voltage withstand performance testing system and method for ion thruster high-voltage cables, which can effectively reduce the technical risks of insufficient ground verification of the voltage withstand performance of high-voltage cables and unreliable in-orbit applications.

[0006] To achieve the above objectives, this application provides a high-voltage withstand voltage performance testing system for ion thruster high-voltage cables, used for ground verification of the withstand voltage performance of ion thruster high-voltage cables. The system includes a vacuum device, an ion thruster, a high-voltage cable, a DC power supply, a stepper motor, and a discharge monitoring system. Specifically: the vacuum device uses flange terminals to connect the internal and external power supplies; the ion thruster is installed inside the vacuum device using an insulated mounting method; the DC power supply is a variable-voltage regulated DC power supply installed outside the vacuum device; the high-voltage cable includes a first cable and a second cable. The first cable is located inside the vacuum device and connects the outer shell of the ion thruster to the flange terminals of the vacuum device; the second cable is located outside the vacuum device and connects the flange terminals of the vacuum device to the port of the DC power supply; the stepper motor is located inside the vacuum device; the middle section of the first cable is fixed to the stepper motor using an insulated mounting method; the discharge monitoring system is located inside the vacuum device and connected to the DC power supply via a signal cable to monitor abnormal phenomena occurring during the power supply process of the high-voltage cable.

[0007] Furthermore, under atmospheric conditions, the withstand voltage between the flange terminals of the vacuum equipment and between the terminals and the housing is ≥ 4 times the withstand voltage of the high-voltage cable to be verified.

[0008] Furthermore, the first and second cables are connected to the ports of the vacuum equipment flange terminals using crimp terminals.

[0009] Furthermore, after the stepper motor starts, it can drive the first cable to bend, with a bending angle ≥10°.

[0010] Furthermore, the gate assembly of the ion thruster consists only of a screen grid.

[0011] Furthermore, the high-voltage cable has undergone irradiation testing.

[0012] Furthermore, abnormal phenomena that occur during the power supply process of high-voltage cables include abnormal discharge, arc flash, and creepage.

[0013] In addition, this application also provides a method for testing the withstand voltage performance of high-voltage cables using an ion thruster system, comprising the following steps: Step 1: Install the vacuum equipment, ion thruster, high-voltage cable, DC power supply, stepper motor and discharge monitoring system. Check and confirm that the bending angle of the first cable driven by the stepper motor is ≥10°, and at the same time ensure that the first cable is within the monitoring range of the discharge monitoring system. Step 2: Turn on the vacuum equipment and adjust the vacuum level to less than 1.0 × 10⁻⁶. -4 Pa, and maintain for at least 6 hours; Step 3: Purify and degas the gas supply pipeline, hollow cathode, and discharge chamber of the ion thruster; Step 4: Start the ion thruster until the discharge chamber is successfully ignited; Step 5: After the ion thruster discharge chamber is successfully ignited and operates continuously for 10 minutes, the grid voltage is applied in a stepped manner. The initial voltage of the grid voltage is set to 1000V, and the adjustment step is 500V. After each adjustment, the voltage is stabilized for 6 minutes until the designed withstand voltage value is reached. Under this parameter mode, the ion thruster operates continuously for 5 hours, and the changes in the operating parameters of the ion thruster and the operation of the discharge monitoring system are observed. Step 6: After the ion thruster has been running stably for 6 hours, turn off the ion thruster, and also turn off the stepper motor and discharge monitoring system.

[0014] The voltage withstand performance testing system and method for ion thruster high-voltage cables provided in this application have the following beneficial effects: This application addresses the matching issue between the power supply requirements of ion thrusters and the power supply characteristics of space high-voltage cables. It constructs a ground verification system for the voltage withstand performance of high-voltage cables, achieving safe and reliable loading of high-voltage cable power supply through stepped loading of the grid voltage. This solves the risk of misjudgment of high-voltage cable power supply performance caused by ion beam scintillation during high-voltage loading, and effectively reduces the technical risks of insufficient ground verification of high-voltage cable voltage withstand performance and unreliable in-orbit application. Attached Figure Description

[0015] The accompanying drawings, which form part of this application, are used to provide a further understanding of the application and to make other features, objects, and advantages of the application more apparent. The illustrative embodiments and descriptions of this application are used to explain the application and do not constitute an undue limitation of the application.

[0016] In the attached diagram: Figure 1 This is a schematic diagram of the voltage withstand performance testing system for ion thruster high-voltage cables provided according to an embodiment of this application; In the diagram: 1-vacuum equipment, 2-ion thruster, 3-high voltage cable, 31-first cable, 32-second cable, 4-DC power supply, 5-stepper motor, 6-discharge monitoring system, 7-flange terminal block. Detailed Implementation

[0017] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0018] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this application described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0019] In this application, the terms "upper," "lower," "left," "right," "front," "rear," "top," "bottom," "inner," "outer," "middle," "vertical," "horizontal," "lateral," and "longitudinal" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for the purpose of better describing this application and its embodiments, and are not intended to limit the indicated device, element, or component to having a specific orientation, or to be constructed and operated in a specific orientation.

[0020] Furthermore, in addition to indicating location or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in some cases to indicate a certain dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0021] In addition, the term "multiple" should mean two or more.

[0022] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0023] like Figure 1As shown, this application provides a voltage withstand performance testing system for high-voltage cables of an ion thruster, used for ground verification of the voltage withstand performance of the high-voltage cable 3 of the ion thruster 2. The system includes a vacuum device 1, an ion thruster 2, a high-voltage cable 3, a DC power supply 4, a stepper motor 5, and a discharge monitoring system 6. Specifically: the vacuum device 1 uses flange terminals 7 to connect the power supply inside and outside the device; the ion thruster 2 is installed inside the vacuum device 1 using an insulated mounting method; the DC power supply 4 is a variable-voltage regulated DC power supply installed outside the vacuum device 1; the high-voltage cable 3 includes a first cable 31 and a second cable 32. The first cable 31 is located inside the vacuum device 1 and connects the outer shell of the ion thruster 2 to the flange terminals 7 of the vacuum device 1; the second cable 32 is located outside the vacuum device 1 and connects the flange terminals 7 of the vacuum device 1 to the port of the DC power supply 4; the stepper motor 5 is located inside the vacuum device 1; the middle area of ​​the first cable 31 is fixed to the stepper motor 5 using an insulated mounting method; the discharge monitoring system 6 is located inside the vacuum device 1 and connected to the DC power supply 4 via a signal cable to monitor abnormal phenomena occurring during the power supply process of the high-voltage cable 3.

[0024] Specifically, the withstand voltage of conventional high-voltage cables used in aerospace is generally below 1000V, which is a low-voltage condition. However, the withstand voltage capability of high-voltage cables used in ion thrusters is generally required to be no less than 6 times the highest operating voltage of the ion thruster (mostly 1000V, with some reaching 1500V). The high-voltage withstand voltage performance test system for ion thruster high-voltage cables provided in this application embodiment is mainly used for ground verification of the withstand voltage performance of the high-voltage cable 3 of the ion thruster 2, thereby ensuring the withstand voltage performance of the high-voltage cable 3 and enabling the normal power-on of the ion thruster 2. The vacuum equipment 1 is mainly used to simulate different vacuum environments by changing the vacuum level inside the vacuum equipment 1. The high-voltage cable 3 is used to connect the ion thruster 2 to the DC power supply 4. It is divided into two parts: a first cable 31 installed inside the vacuum equipment 1 and a second cable 32 installed outside the vacuum equipment 1. The ion thruster 2 is fixed inside the vacuum equipment 1 by insulated installation. Then, its outer shell is connected to the flange terminal 7 of the vacuum equipment 1 through the first cable 31. During the test, it is determined whether to perform grounding treatment according to the actual situation. The DC power supply 4 is a variable voltage regulated DC power supply. Its power supply interface is connected to the flange terminal 7 of the vacuum equipment 1 through the second cable 32. It is used to supply power to the ion thruster 2 and various structures of the system. The stepper motor 5 is mainly used to drive the first cable 31 to bend without affecting the installation and fastening effect of the high-voltage cable 3. The discharge monitoring system 6 can monitor abnormal phenomena such as high-definition arcing that occur during the power supply process of the high-voltage cable 3 in a vacuum environment.

[0025] Furthermore, under atmospheric conditions, the withstand voltage between the flange terminals 7 of vacuum equipment 1 and between the terminals and the casing is ≥ 4 times the withstand voltage of the high-voltage cable 3 to be verified. Based on leakage current calculations, when the withstand voltage between the flange terminals 7 and between the terminals and the casing is more than 4 times the voltage of the high-voltage cable 3 to be verified, the leakage current has a negligible impact on the withstand voltage test of the high-voltage cable, thus ensuring the accuracy of the test.

[0026] Furthermore, the first cable 31 and the second cable 32 are connected to the port of the flange terminal 7 of the vacuum equipment 1 using crimp terminals. Using crimp terminals for port connection allows for better matching of the structure of the flange terminal 7.

[0027] Furthermore, after the stepper motor 5 starts, it can drive the first cable 31 to bend at a bending angle ≥10°. Bending the first cable 31 via the stepper motor 5 is primarily to simulate the bending effect generated when the mechanism fixing the high-voltage cable 3 on the satellite swings. Frequent bending can cause micro-cracks in the insulation material of the high-voltage cable 3, thus affecting its withstand voltage performance. In this embodiment, considering the bending radius requirements in the general specifications of the high-voltage cable 3 and the swing angle of the mechanism fixing the high-voltage cable 3 on the satellite, the bending angle is preferably ≥10°, thereby verifying the change in withstand voltage performance of the high-voltage cable 3 under frequent bending during energized operation.

[0028] Furthermore, the gate assembly of the ion thruster 2 consists only of a screen grid. Since the gate assembly is prone to abnormal discharge under high voltage, the operating parameters of the ion thruster 2 will exhibit low voltage and high current, similar to the abnormal phenomenon observed in the withstand voltage test of the high-voltage cable 3. To avoid misjudgment, the gate assembly uses only a screen grid, thus solving the problem of high-voltage arcing in the gate assembly.

[0029] Furthermore, the high-voltage cable 3 has undergone irradiation testing, in which the irradiation dose is not lower than its designed maximum tolerable dose.

[0030] Furthermore, abnormal phenomena that occur during the power supply process of high-voltage cable 3 include abnormal discharge, arc flash, and creepage.

[0031] Furthermore, this application also provides a method for testing the withstand voltage performance of high-voltage cables using an ion thruster system, comprising the following steps: Step 1: Install the vacuum equipment 1, ion thruster 2, high-voltage cable 3, DC power supply 4, stepper motor 5 and discharge monitoring system 6. Check and confirm that the bending angle of the first cable 31 driven by the stepper motor 5 is ≥10°, and at the same time ensure that the first cable 31 is within the monitoring range of the discharge monitoring system 6. Step 2: Turn on vacuum device 1 to make the vacuum level of vacuum device 1 less than 1.0 × 10⁻⁶. -4 Pa, and maintain for at least 6 hours; Step 3: Purify and degas the gas supply pipeline, hollow cathode, and discharge chamber of ion thruster 2. Step 4: Start ion thruster 2 according to the ignition start strategy of ion thruster 2 until the discharge chamber is successfully ignited; Step 5: After the discharge chamber of ion thruster 2 is successfully ignited and operates continuously for 10 minutes, the grid voltage is applied in a stepped manner. The initial voltage of the grid voltage is set to 1000V, and the adjustment step is 500V. After each adjustment, the device operates stably for 6 minutes until the designed withstand voltage value is reached. Under this parameter mode, ion thruster 2 operates continuously for 5 hours. The changes in the operating parameters of ion thruster 2 and the operation of discharge monitoring system 6 are observed. Step 6: After the ion thruster 2 has been running stably for 6 hours, turn off the ion thruster 2, and also turn off the stepper motor 5 and the discharge monitoring system 6.

[0032] Specifically, in this embodiment, when the ion thruster 2 is running, abnormal leakage will occur if the high-voltage withstand voltage performance cannot meet the requirements. This is characterized by the constant voltage power supply failing to reach its rated value, the voltage being abnormally low, the leakage current in the constant current source increasing abnormally, and the actual output constant current ratio decreasing. At this time, the discharge monitoring system will detect abnormal discharge and arcing phenomena. Therefore, during the 6-hour operation of the ion thruster 2, if the voltage and current parameters of each electrode of the ion thruster 2 remain stable and controlled within the design requirements, and the discharge monitoring system 6 does not detect abnormal discharge, arcing, or creepage phenomena, it indicates that the withstand voltage performance of the high-voltage cable 3 meets its own withstand voltage design requirements; otherwise, its withstand voltage performance cannot meet its withstand voltage design requirements.

[0033] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A voltage withstand performance testing system for high-voltage cables of ion thrusters, characterized in that, Ground-based verification of the withstand voltage performance of high-voltage cables for ion thrusters includes vacuum equipment, ion thrusters, high-voltage cables, DC power supplies, stepper motors, and discharge monitoring systems, among which: The vacuum equipment uses flange terminals to connect the power supply inside and outside the equipment; The ion thruster is installed inside the vacuum equipment using an insulated mounting method; The DC power supply is a variable regulated DC power supply, which is installed outside the vacuum equipment; The high-voltage cable includes a first cable and a second cable. The first cable is disposed inside the vacuum equipment and is used to connect the outer shell of the ion thruster to the flange terminal of the vacuum equipment. The second cable is disposed outside the vacuum equipment and is used to connect the flange terminal of the vacuum equipment to the port of the DC power supply. The stepper motor is installed inside the vacuum equipment; The middle section of the first cable is fixed to the stepper motor using an insulated mounting method; The discharge monitoring system is installed inside the vacuum equipment and connected to the DC power supply via a signal cable. It is used to monitor abnormal phenomena that occur during the power supply process of the high-voltage cable.

2. The high-voltage withstand voltage performance testing system for ion thruster cables according to claim 1, characterized in that, Under atmospheric conditions, the withstand voltage between the flange terminals of the vacuum equipment and between the terminals and the outer casing is ≥ 4 times the withstand voltage of the high-voltage cable to be verified.

3. The high-voltage withstand voltage performance testing system for ion thruster cables according to claim 2, characterized in that, The first cable and the second cable are connected to the port of the flange terminal of the vacuum equipment using crimp terminals.

4. The voltage withstand performance testing system for ion thruster high-voltage cables according to claim 3, characterized in that, After the stepper motor is started, it can drive the first cable to bend, with a bending angle ≥10°.

5. The voltage withstand performance testing system for ion thruster high-voltage cables according to claim 4, characterized in that, The gate assembly of the ion thruster consists only of a screen grid.

6. The voltage withstand performance testing system for ion thruster high-voltage cables according to claim 5, characterized in that, The high-voltage cable has undergone irradiation testing.

7. The high-voltage withstand voltage performance testing system for ion thruster cables according to claim 6, characterized in that, Abnormal phenomena that occur during the power supply process of high-voltage cables include abnormal discharge, arc flash, and creepage.

8. A method for testing the withstand voltage performance of high-voltage cables using the ion thruster high-voltage cable testing system as described in claim 7, characterized in that, Includes the following steps: Step 1: Install the vacuum equipment, ion thruster, high-voltage cable, DC power supply, stepper motor and discharge monitoring system. Check and confirm that the bending angle of the first cable driven by the stepper motor is ≥10°, and at the same time ensure that the first cable is within the monitoring range of the discharge monitoring system. Step 2: Turn on the vacuum equipment and adjust the vacuum level to less than 1.0 × 10⁻⁶. -4 Pa, and maintain for at least 6 hours; Step 3: Purify and degas the gas supply pipeline, hollow cathode, and discharge chamber of the ion thruster; Step 4: Start the ion thruster until the discharge chamber is successfully ignited; Step 5: After the ion thruster discharge chamber is successfully ignited and operates continuously for 10 minutes, the grid voltage is applied in a stepped manner. The initial voltage of the grid voltage is set to 1000V, and the adjustment step is 500V. After each adjustment, the voltage is stabilized for 6 minutes until the designed withstand voltage value is reached. Under this parameter mode, the ion thruster operates continuously for 5 hours, and the changes in the operating parameters of the ion thruster and the operation of the discharge monitoring system are observed. Step 6: After the ion thruster has been running stably for 6 hours, turn off the ion thruster, and also turn off the stepper motor and discharge monitoring system.

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