Hall thruster and excitation method of Hall thruster

Abstract

The invention discloses a Hall thruster and an excitation method of the Hall thruster, and relates to the technical field of power devices.On one hand, a regulation and control coil is additionally arranged in the Hall thruster, a second magnetic field is generated through the regulation and control coil, and magnetic field distribution in a discharge area is adjusted; discharge current oscillation or anode voltage oscillation of the Hall thruster is effectively suppressed, and stable performance of the Hall thruster is ensured. On the other hand, the first excitation coil and the second excitation coil are connected in series, so that the first excitation coil and the second excitation coil share the first power supply, the regulation and control coil and the hollow cathode share the third power supply, and meanwhile, the first power supply, the second power supply and the third power supply are connected and can share the common ground; therefore, the number of power supplies of the Hall thruster can be greatly reduced, and the cost of the Hall thruster can be effectively reduced under the condition that the number of regulation and control coils is increased.

Description

Technical Field

[0001] The present application relates to the technical field of power devices, and particularly to a Hall thruster and a method for exciting a Hall thruster. Background Art

[0002] Compared with other types of thrusters (such as cold gas thrusters and chemical thrusters), Hall thrusters have comprehensive advantages in terms of cost and performance, and are widely used in various spacecrafts and are used to perform important tasks such as orbit transfer, position keeping, and terminal reentry.

[0003] During the life cycle of a Hall thruster, as the usage time of the Hall thruster increases, the performance of the Hall thruster may change. In order to cope with this performance change, the Hall thruster needs to be modified. During the modification process, the cost of the Hall thruster will inevitably increase. However, in order to meet the demand for low cost of commercial satellites, it is necessary to compress the cost of the Hall thruster and ensure a certain degree of controllability. Summary of the Invention

[0004] The present application provides a Hall thruster and a method for exciting a Hall thruster, so as to at least solve the problems of high cost and poor controllability of Hall thrusters in related technologies.

[0005] The present application provides a Hall thruster, and the Hall thruster includes: A hollow cathode for emitting electrons; A Hall accelerator, including an anode, a discharge region, a regulation coil, a first excitation coil and a second excitation coil connected in series, the first excitation coil and the second excitation coil are used to generate a first magnetic field, the first magnetic field is at least distributed in the discharge region, the anode attracts the electrons emitted by the hollow cathode into the magnetic field of the discharge region for ionization and generates a discharge current, the regulation coil is used to generate a second magnetic field, the second magnetic field is used to adjust the magnetic field distribution in the discharge region, the excitation coil and the regulation coil are deployed in a non-series manner, and the excitation power supplies of the excitation coil and the regulation coil are different; A first power supply, one end of the first power supply is connected to the anode, and the other end of the first power supply is connected to the first excitation coil and the second excitation coil connected in series; A second power supply, one end of the second power supply is connected to the hollow cathode, and the other end of the second power supply is connected to the first power supply through the first excitation coil and the second excitation coil; A third power supply, one end of the third power supply is connected to the hollow cathode through a first switch and connected to the regulation coil through a second switch, and the other end of the third power supply is connected to the first power supply and the second power supply.

[0006] The present application provides an excitation method for the above-mentioned Hall thruster, the method comprising: Inputting working fluid into the hollow cathode; When the flow rate of the working medium reaches a stable state, controlling the first switch to close, and exciting the hollow cathode through a third power supply, so that the hollow cathode generates initial electrons; When the initial electrons are generated, the hollow cathode is excited by a second power supply so that the initial electrons react with the working medium and trigger discharge of the hollow cathode; When the hollow cathode discharge is successful, the first excitation coil and the second excitation coil are excited by the first power supply, so that the first excitation coil and the second excitation coil generate a first magnetic field.

[0007] In the technical solutions of some embodiments of the present application, on the one hand, a control coil is added to the Hall thruster. This control coil generates a second magnetic field, which adjusts the magnetic field distribution in the discharge region, effectively suppressing discharge current oscillation or anode voltage oscillation in the Hall thruster and ensuring stable performance. On the other hand, by connecting a first excitation coil and a second excitation coil in series, the first and second excitation coils share a first power supply, and the control coil and the hollow cathode share a third power supply. Furthermore, the first, second, and third power supplies are connected, allowing them to share a common ground. This significantly reduces the number of power supplies in the Hall thruster, effectively reducing the cost of the Hall thruster and improving its controllability while adding a control coil. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] In order to more clearly illustrate the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0009] Figure 1 Schematic diagram of the etching of discharge channels of some Hall thrusters over time; Figure 2 Schematic diagram of the change of discharge current of some Hall thrusters with the length of use; Figure 3 Schematic diagram of the change of anode voltage of some Hall thrusters with the length of use; Figure 4 A schematic diagram of a Hall thruster provided for some embodiments of the present application; Figure 5 for Figure 4 Schematic diagram of magnetic field guidance of Hall thruster; Figure 6 Schematic diagram of a Hall thruster provided for another embodiment of the present application; Figure 7 Schematic diagram of a Hall thruster provided for another embodiment of the present application; Figure 8 Flow schematic diagram of an excitation method provided for some embodiments of the present application; Figure 9 Flow schematic diagram for regulating the discharge current oscillation of a Hall thruster provided for some embodiments of the present application; Figure 10 Schematic diagram of the magnetic field distribution in the discharge region under the rated operating conditions of a Hall thruster provided for some embodiments of the present application; Figure 11 Schematic diagram of the magnetic field distribution in the discharge region after the first regulation provided for some embodiments of the present application; Figure 12 Schematic diagram of the magnetic field distribution in the discharge region after the second regulation provided for some embodiments of the present application; Figure 13 For Figure 10 Discharge current schematic diagram of the Hall thruster in Figure 14 For Figure 11 Discharge current schematic diagram of the Hall thruster in Figure 15 For Figure 12 Discharge current schematic diagram of the Hall thruster in Figure 16 Module schematic diagram of a Hall propulsion system provided for some embodiments of the present application. Detailed implementation manners

[0010] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0011] It should be noted that the orientation or positional relationship indicated by terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present application. The terms "mounted", "connected", "coupled" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. The terms "parallel", "perpendicular", "equal" include the described situations and situations similar to the described situations, and the range of the similar situations is within an acceptable deviation range, where the acceptable deviation range is determined by those of ordinary skill in the art considering the measurements being discussed and the errors associated with the measurements of specific quantities (i.e., the limitations of the measurement system). For example, "parallel" includes absolute parallel and approximate parallel, and the acceptable deviation range of approximate parallel can be, for example, within 5° deviation; "perpendicular" includes absolute perpendicular and approximate perpendicular, and the acceptable deviation range of approximate perpendicular can also be, for example, within 5° deviation. "Equal" includes absolute equal and approximate equal, and the acceptable deviation range of approximate equal can be, for example, that the difference between the two equal ones is less than or equal to 5% of either one. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific situations.

[0012] During the life cycle of a Hall thruster, as the usage time of the Hall thruster increases, performance changes may occur in the Hall thruster. For example, referring to Figure 1 , it is a schematic diagram of the etching of the discharge channels of some Hall thrusters with the usage duration. Taking the Hall thruster being used for 1x hours as an example. After the Hall thruster is used for 1x hours, the abc area on the right side of the dotted line in its discharge channel will be etched away. Based on a similar principle, it can be seen that as the usage duration of the Hall thruster increases, the etched area of the discharge channel gradually increases. As the etched area of the discharge channel increases, the discharge current and anode voltage of the Hall thruster may shift to a more severe operating condition. For example, referring to Figure 2 and Figure 3 . Figure 2 It is a schematic diagram of the change in the discharge current of some Hall thrusters with the usage duration. Figure 3 It is a schematic diagram of the change in the anode voltage of some Hall thrusters with the usage duration. From Figure 2and Figure 3 It can be seen that as the usage duration increases, the discharge current and anode voltage of the Hall thruster both exhibit oscillation phenomena. In this case, it is necessary to adjust the magnetic field distribution in the discharge region of the Hall thruster to make the discharge current and anode voltage tend to be stable again.

[0013] In view of this, the present application provides a modified Hall thruster, which supports adjusting the magnetic field distribution in the discharge region of the Hall thruster, and at the same time, can effectively control the cost of the Hall thruster.

[0014] With reference to Figure 4 , a schematic diagram of the Hall thruster 100 provided for some embodiments of the present application. Figure 1 In , the Hall thruster 100 includes a hollow cathode 101, a Hall accelerator 102, a first power supply P1, a second power supply P2, and a third power supply P3.

[0015] The hollow cathode 101 is used to emit electrons. The Hall accelerator 102 includes an anode 5, a discharge region 15, a regulation coil 10, a first excitation coil 8 and a second excitation coil 9 connected in series. The first excitation coil 8 and the second excitation coil 9 are used to generate a first magnetic field, and the first magnetic field is at least distributed in the discharge region 15. The anode 5 attracts the electrons emitted by the hollow cathode 101 into the magnetic field of the discharge region 15 for ionization and generates a discharge current. The regulation coil 10 is used to generate a second magnetic field, and the second magnetic field is used to adjust the magnetic field distribution in the discharge region 15.

[0016] Specifically, in this embodiment, the Hall thruster 100 further includes a first magnetic pole 1, a second magnetic pole 2, a magnetic conductive bottom plate 3, a first magnetic shield 6, and a second magnetic shield 7. After the first excitation coil 8 and the second excitation coil 9 are excited by an excitation power supply, a current can be generated in the first excitation coil 8 and the second excitation coil 9, and then the first excitation coil 8 and the second excitation coil 9 can generate a first magnetic field. The first magnetic pole 1, the second magnetic pole 2, the magnetic conductive bottom plate 3, the discharge channel 4, the first magnetic shield 6, and the second magnetic shield 7 can be used as magnetic circuit construction components. After the first magnetic field generated by the first excitation coil 8 and the second excitation coil 9 is guided by the first magnetic pole 1, the second magnetic pole 2, the discharge channel 4, the first magnetic shield 6, the second magnetic shield 7, and the magnetic conductive bottom plate 3, it is at least distributed in the discharge region 15 surrounded by the discharge channel 4 and forms a closed path of the magnetic field (i.e., a magnetic circuit).

[0017] For easy understanding, with reference to Figure 5 , for Figure 4Schematic diagram of magnetic field guidance of the Hall thruster 100 in []. For example, after the second excitation coil 9 is energized, a first magnetic field can be generated around the second magnetic pole 2 and in the discharge region 15. The first magnetic field around the second magnetic pole 2 will pass through the discharge channel 4 and reach the first magnetic pole 1 after being guided by the magnetic conductive bottom plate 3, and then reach the second magnetic pole 2 from the first magnetic pole 1. In this way, a closed path of the magnetic field is formed. During the process of the first magnetic field reaching the second magnetic pole 2 from the first magnetic pole 1, the first magnetic shield 6 and the second magnetic shield 7 can capture the first magnetic field into the discharge region 15, so as to reduce magnetic field leakage and improve magnetic field utilization rate. By adjusting the magnetic shield parameters of the first magnetic shield 6 and the second magnetic shield 7, the magnetic field distribution in the discharge region 15 can be adjusted. Among them, the magnetic shield parameters include but are not limited to the magnetic shield position, magnetic shield shape, etc.

[0018] Similarly, after the first excitation coil 8 is energized, a first magnetic field can be generated around the first magnetic pole 1 and in the discharge region 15. The first magnetic field around the first magnetic pole 1 will pass through the discharge channel 4 and reach the second magnetic pole 2 after being guided by the magnetic conductive bottom plate 3, and then reach the first magnetic pole 1 from the second magnetic pole 2.

[0019] After being guided by the magnetic circuit construction component, a negative-gradient radial magnetic field distribution can be formed in the axial direction AB of the discharge region 15. The anode 5 is used to attract the electrons emitted by the hollow cathode 101 into the magnetic field of the discharge region 15 for ionization and generate a discharge current. Specifically, on the one hand, the anode 5 can be used as the high-potential end of the discharge region 15 to attract the electrons emitted by the hollow cathode 101 to move along the anode 5. At the end CD (i.e., the outlet of the discharge region 15) of the discharge region 15, the electrons can be captured by the magnetic field in the discharge region 15 and thus enter the discharge region 15. On the other hand, the anode 5 can be used as a gas distributor to fill the discharge region 15 with gas (such as xenon, krypton, etc.). The gas in the discharge region 15 can collide with the electrons whose energy exceeds the gas ionization energy to generate plasma, and this process is ionization. During the ionization process, due to the loss of electron energy, a positive-gradient electric field will be formed in the axial direction AB of the discharge region 15, that is, the farther away from the anode 5, the stronger the electric field intensity. The positive-gradient electric field can be used to accelerate and eject the ions generated by ionization from the end CD of the discharge region 15, thereby generating thrust, and at the same time, generating a discharge current. Usually, the magnitude of the discharge current directly affects the ionization rate and intensity. When the discharge current increases, it means that more electrons are accelerated and participate in the ionization process, so that more ions can be generated. These ions are accelerated and ejected from the end CD of the discharge region 15 under the action of the electric field, generating thrust. Therefore, to a certain extent, the increase of the discharge current can improve the thrust of the Hall thruster 100. However, when the discharge current increases to a certain extent, ionization will tend to saturate, and at this time, the increase of the discharge current will no longer improve the thrust of the Hall thruster 100.

[0020] When the oscillation amplitude of the discharge current or the anode voltage of the Hall thruster 100 does not fall below the target amplitude, the regulation coil 10 can be used to generate a second magnetic field, which is used to adjust the magnetic field distribution in the discharge region 15 so that the oscillation amplitude of the discharge current or the anode voltage is lower than the target amplitude. Specifically, the second magnetic field can also be at least distributed in the discharge region 15. The first magnetic field and the second magnetic field in the discharge region 15 are superimposed on each other, and the magnetic field distribution in the discharge region 15 can be adjusted. When the magnetic field distribution in the discharge region 15 changes, the electron behavior (such as electron velocity) in the Hall thruster 100 can change, thereby effectively suppressing the discharge current oscillation or the anode voltage oscillation of the Hall thruster 100.

[0021] In this embodiment, the excitation coils 8, 9 and the regulation coil 10 are deployed in a non-series manner, and the excitation power supplies of the excitation coils 8, 9 and the regulation coil 10 are different. For example, the excitation coils 8, 9 can be excited by a first power supply, and the regulation coil 10 can be excited by a third power supply. In this way, the first magnetic field generated by the excitation coils 8, 9 and the second magnetic field generated by the regulation coil 10 can be controlled separately, thereby improving the adjustment flexibility. For example, the current direction of the excitation coils 8, 9 can be opposite to the current direction of the regulation coil 10, so that the excitation direction of the excitation coils 8, 9 is opposite to the excitation direction of the regulation coil 10. On the contrary, if the excitation coils 8, 9 and the regulation coil 10 are deployed in series, the current direction of the excitation coils 8, 9 needs to be the same as the current direction of the regulation coil 10. In this way, the excitation direction of the excitation coils 8, 9 needs to be the same as the excitation direction of the regulation coil 10, which is not convenient for flexibly adjusting the magnetic field distribution in the discharge region 15 according to actual needs.

[0022] Since the regulation coil 10 is added to the Hall thruster 100, an excitation power supply for the regulation coil 10 also needs to be added, which will undoubtedly increase the cost of the Hall thruster 100. In view of this, the present application proposes the following power connection design scheme: One end of the first power supply P1 is connected to the anode 5, and the other end of the first power supply P1 is connected to the series-connected first excitation coil 8 and second excitation coil 9. Specifically, the positive pole of the first power supply P1 is connected to the anode 5, and the negative pole of the first power supply P1 is connected to the series-connected first excitation coil 8 and second excitation coil 9, realizing the series connection of the anode 5, the first excitation coil 8 and the second excitation coil 9.

[0023] One end of the second power supply P2 is connected to the hollow cathode 101, and the other end of the second power supply P2 is connected to the first power supply P1 through the first excitation coil 8 and the second excitation coil 9. Specifically, the positive electrode of the second power supply P2 is connected to the hollow cathode 101, and the negative electrode of the second power supply P2 is connected to the negative electrode of the first power supply P1 through the first excitation coil 8 and the second excitation coil 9. In this way, the first power supply P1 and the second power supply P2 can share a common ground.

[0024] One end of the third power supply P3 is connected to the hollow cathode 101 through the first switch K1 and is connected to the control coil 10 through the second switch K2, and the other end of the third power supply P3 is connected to the first power supply P1 and the second power supply P2. Specifically, the positive electrode of the third power supply P3 is connected to the hollow cathode 101 through the first switch K1 and is connected to the control coil 10 through the second switch K2, and the negative electrode of the third power supply P3 is connected to the negative electrodes of the first power supply P1 and the second power supply P2. In this way, the first power supply P1 and the second power supply P2 can share a common ground.

[0025] In this embodiment, the hollow cathode 101 may include a holder 11, an emitter 12, a heater 13, and a cathode tube 14. One end of the second power supply P2 is connected to the holder 11, and one end of the third power supply P3 is connected to the heater 13 through the first switch K1. Specifically, the positive electrode of the second power supply P2 is connected to the holder 11, and the positive electrode of the third power supply P3 is connected to the heater 13 through the first switch K1. Among them, when the first switch K1 is closed, the third power supply P3 is used to excite the heater 13 to heat the emitter 12, so that after the emitter 12 reaches the electron emission temperature, initial electrons are generated. The second power supply P2 is used to excite the holder 11, so that the initial electrons interact with the gas and trigger the discharge of the hollow cathode 101. During the discharge process of the hollow cathode 101, the hollow cathode 101 emits electrons externally.

[0026] Specifically, the cathode tube 14 can be a hollow structure with a variable diameter, which can serve as a flow channel for a gas (such as xenon or krypton). Furthermore, the emitter 12 is disposed within the large-diameter hollow structure. After the heater 13 is energized by the third power source P3, it can heat the emitter 12. When the temperature of the emitter 12 reaches the electron emission temperature, initial electrons can be emitted. At this point, after the hollow structure of the cathode tube 14 is filled with gas and the contact holder 11 is energized, a primary discharge can first occur in the terminal slit region between the contact holder 11 and the cathode tube 14, generating plasma. Subsequently, the plasma in the terminal slit region can migrate to the hollow region of the emitter 12, where it is maintained continuously through electron bombardment or ion bombardment, generating a self-consistent plasma potential drop between the emitter 12 and the contact holder 11, forming a discharge at the hollow cathode 101. After the hollow cathode 101 is discharged, the contact 11 can lead the electrons in the hollow region of the emitter 12 out of the hollow cathode 101 , thereby achieving the purpose of the hollow cathode 101 emitting electrons.

[0027] When the magnetic field distribution in the discharge region 15 needs to be adjusted, the second switch K2 is closed, and the third power supply P3 is used to excite the control coil 10 so that the control coil 10 generates a second magnetic field.

[0028] In summary, in the technical solutions of some embodiments of the present application, on the one hand, a control coil 10 is added to the Hall thruster 100. The control coil 10 generates a second magnetic field, which adjusts the magnetic field distribution in the discharge region 15, effectively suppressing discharge current oscillations or anode voltage oscillations in the Hall thruster 100 and ensuring stable performance of the Hall thruster 100. On the other hand, by connecting the first excitation coil 8 and the second excitation coil 9 in series, the first excitation coil 8 and the second excitation coil 9 share a first power source P1, and the control coil 10 and the hollow cathode 101 share a third power source P3. Furthermore, the first power source P1, the second power source P2, and the third power source P3 are connected, allowing them to share a common ground. This significantly reduces the number of power sources in the Hall thruster 100, thereby effectively reducing the cost of the Hall thruster 100 while adding the control coil 10.

[0029] In some embodiments, the Hall thruster 100 may include only one control coil 10. One of the first excitation coil 8 and the second excitation coil 9 is coaxial with the control coil 10. For example, Figure 4 In the embodiment, the control coil 10 is coaxial with the first excitation coil 8. Of course, it is understood that the control coil 10 can also be coaxial with the second excitation coil 9. This application does not impose any restrictions on this. This coaxial deployment ensures that the second magnetic field generated by the control coil 10 can more effectively and accurately adjust the magnetic field distribution in the discharge region 15.

[0030] In some other embodiments, the regulation coil 10 may include a first regulation coil and a second regulation coil. The first excitation coil 8 may be coaxial with the first regulation coil, and the second excitation coil 9 may be coaxial with the second regulation coil. In this way, the second magnetic field generated by the first regulation coil can be mainly used to adjust the magnetic field distribution of the first magnetic field generated by the first excitation coil 8, and the second magnetic field generated by the second regulation coil can be mainly used to adjust the magnetic field distribution of the first magnetic field generated by the second excitation coil 9. By adjusting the magnetic field distribution in the discharge region 15 through at least two regulation coils, the effect is better and the adjustment method is more flexible.

[0031] Furthermore, when the Hall thruster 100 includes a plurality of regulation coils 10 (such as including a first regulation coil and a second regulation coil), the second switch K2 may include a plurality of sub-switches. The plurality of regulation coils 10 correspond to the plurality of sub-switches one by one, and each regulation coil 10 is connected to the third power supply P3 through the corresponding sub-switch. In this way, based on the opening or closing of the sub-switches, each regulation coil 10 can be controlled individually, and thus when adjusting the magnetic field distribution in the discharge region 15, the adjustment method can be made more flexible.

[0032] In some embodiments, for a target excitation coil and a target regulation coil that are coaxial, the target regulation coil may be located radially outside the target excitation coil, or the target excitation coil may be located radially outside the target regulation coil. When the target regulation coil is located radially outside the target excitation coil, the radius of the target regulation coil is greater than the radius of the target excitation coil; when the target excitation coil is located radially outside the target regulation coil, the radius of the target excitation coil is greater than the radius of the target regulation coil. For example Figure 4 in, that is, the target regulation coil is located radially outside the target excitation coil. The principle that the target excitation coil is located radially outside the target regulation coil is opposite to the principle that the target regulation coil is located radially outside the target excitation coil, and will not be elaborated here.

[0033] In some other embodiments, in the axial direction of the target excitation coil and the target regulation coil, the target regulation coil is located on one side of the target excitation coil. For the convenience of understanding, refer to Figure 6 , which is a schematic diagram of the Hall thruster 200 provided by another embodiment of the present application. The principle of the Hall thruster 200 is basically similar to that of the Hall thruster 100. The main difference is that the regulation coil 20 (i.e., the target regulation coil) is coaxial with the first excitation coil 28 (i.e., the target excitation coil), and the regulation coil 20 is located on one side of the first excitation coil 28.

[0034] Refer to Figure 7, a schematic diagram of the Hall thruster 300 provided for another embodiment of the present application. The principle of the Hall thruster 300 is basically similar to that of the Hall thruster 100. The main difference is that Figure 7 in Figure 7 , the regulation coil 30 is not coaxial with the first excitation coil 38 or the second excitation coil 39, but is arranged on the side of the anode 35 away from the discharge region 315.

[0035] In specific implementation, one of the above deployment methods can be selected according to requirements to deploy the standard regulation coil, and the present application does not limit this.

[0036] Correspondingly, the present application also provides an excitation method for any of the above Hall thrusters. Referring to Figure 8 , a schematic flow chart of the excitation method provided for some embodiments of the present application. Figure 8 in Figure 8 , the excitation method includes the following steps: Step 801, inputting a working medium into the hollow cathode.

[0037] Among them, the working medium is the gas required during the operation of the Hall thruster, such as xenon, krypton, etc.

[0038] Step 802, when the flow rate of the working medium reaches a steady state, controlling the first switch to close and exciting the hollow cathode through the third power supply so that the hollow cathode generates initial electrons.

[0039] Step 803, when initial electrons are generated, exciting the hollow cathode through the second power supply so that the initial electrons interact with the working medium and trigger hollow cathode discharge.

[0040] Step 804, when the hollow cathode discharge is successful, exciting the first excitation coil and the second excitation coil through the first power supply so that the first excitation coil and the second excitation coil generate a first magnetic field.

[0041] Furthermore, after exciting the hollow cathode, when the discharge of the hollow cathode reaches a self-sustaining state, controlling the first switch to change from the closed state to the open state, controlling the third power supply to stop exciting the hollow cathode, and after a discharge current is generated in the Hall accelerator, controlling the second power supply to stop exciting the hollow cathode. In this way, power waste can be reduced.

[0042] For easy understanding, referring to Figure 9 , a schematic flow chart of regulating the discharge current oscillation of the Hall thruster provided for some embodiments of the present application. Figure 9 The method in Figure 9 includes the following steps: Step S901, obtaining the first average discharge current and the first peak-to-peak discharge current of the Hall thruster.

[0043] Specifically, the peak-to-peak value of the first discharge current is the difference between the highest amplitude and the lowest amplitude of the first discharge current of the Hall thruster. The discharge current of the Hall thruster at multiple time points within the most recent preset duration can be obtained. Based on the discharge current at these multiple time points, the average value of the first discharge current and the peak-to-peak value of the first discharge current of the Hall thruster within the most recent preset duration are obtained. For example, the discharge current of the Hall thruster at multiple time points within the most recent 5 milliseconds is obtained. By averaging the discharge current at these multiple time points, the average value of the first discharge current can be obtained. Among the discharge currents at these multiple time points, the difference between the adjacent highest amplitude and the lowest amplitude can be used as the peak-to-peak value of the first discharge current.

[0044] Step S902: Based on the peak-to-peak value of the first discharge current and the average value of the first discharge current, determine whether the oscillation amplitude of the discharge current of the Hall thruster is lower than the target amplitude.

[0045] In this embodiment, the average value of the first discharge current can be multiplied by the first preset ratio to obtain the first reference current value. If the difference between the peak-to-peak value of the first discharge current and the average value of the first discharge current is greater than the first reference current value, it is determined that the oscillation amplitude of the discharge current of the Hall thruster is not lower than the target amplitude. For example, the first preset ratio can be 80%. Suppose the average value of the first discharge current is 0.5 A and the peak-to-peak value of the first discharge current is 1.2 A. 0.5 can be multiplied by 80% to obtain the first reference current value of 0.4. The difference between the peak-to-peak value of the first discharge current and the average value of the first discharge current is 1.2 - 0.5, that is, 0.7. Since 0.7 is greater than the first reference current value of 0.4, it can be determined that the oscillation amplitude of the discharge current of the Hall thruster is not lower than the target amplitude. On the contrary, if the peak-to-peak value of the first discharge current is 0.7 A. The difference between the peak-to-peak value of the first discharge current and the average value of the first discharge current is 0.7 - 0.5, that is, 0.2. Since 0.2 is not greater than the first reference current value of 0.4, it can be determined that the oscillation amplitude of the discharge current of the Hall thruster is lower than the target amplitude.

[0046] Of course, the method for determining the reference current value is not limited to the above method. For example, a difference threshold (such as 0.6) can be set. If the difference between the peak-to-peak value of the first discharge current and the average value of the first discharge current is greater than the difference threshold, it can be determined that the oscillation amplitude of the discharge current of the Hall thruster is not lower than the target amplitude.

[0047] In the above embodiment, generating the first reference current value dynamically according to the average value of the first discharge current can improve the judgment accuracy.

[0048] Step S903: If the oscillation amplitude of the discharge current is not lower than the target amplitude, then energize the regulation coil of the Hall thruster to adjust the magnetic field distribution in the discharge region of the Hall thruster. Among them, when the magnetic field distribution in the discharge region changes, the discharge current of the Hall thruster changes.

[0049] Specifically, the peak-to-peak value of the first discharge current can be multiplied by a second preset ratio to obtain a second current reference value. According to the second current reference value, the excitation voltage of the regulation coil is determined, and the regulation coil is excited according to the excitation voltage. For example, the second preset ratio can be 20%. Suppose the peak-to-peak value of the first discharge current is 1 A. After multiplying the peak-to-peak value of the first discharge current by the second preset ratio, the obtained second current reference value is 0.2 A. Based on the second current reference value of 0.2 A, the excitation voltage of the regulation coil can be controlled so that the regulation coil generates a current of 0.2 A.

[0050] Determining the excitation voltage of the regulation coil according to the peak-to-peak value of the first discharge current can effectively adjust the magnetic field distribution in the discharge region.

[0051] In some embodiments, after exciting the regulation coil according to the second current reference value, the method of the present application may further include: Obtaining the average value of the second discharge current and the peak-to-peak value of the second discharge current of the Hall thruster, where the peak-to-peak value of the second discharge current is the difference between the highest amplitude and the lowest amplitude of the second discharge current of the Hall thruster; If the peak-to-peak value of the second discharge current is less than the peak-to-peak value of the first discharge current, the average value of the second discharge current is multiplied by a third preset ratio to obtain a third current reference value; If the difference between the peak-to-peak value of the second discharge current and the average value of the second discharge current is greater than the third current reference value, the excitation voltage of the regulation coil is continuously adjusted; If the difference between the peak-to-peak value of the second discharge current and the average value of the second discharge current is not greater than the third current reference value, the adjustment of the excitation voltage of the regulation coil is stopped.

[0052] Among them, obtaining the average value of the second discharge current and the peak-to-peak value of the second discharge current is similar to the principle of obtaining the average value of the first discharge current and the peak-to-peak value of the first discharge current, which will not be elaborated here.

[0053] For example, the third preset ratio can be 50%. Assume that the average value of the second discharge current is 0.4 A and the peak-to-peak value of the first discharge current is 0.7 A. After multiplying the average value of the second discharge current by the third preset ratio, the third current reference value of 0.2 A is obtained. The difference between the peak-to-peak value of the second discharge current and the average value of the second discharge current is 0.7 - 0.4, that is, 0.3. Since 0.3 is greater than the third current reference value of 0.2 A, therefore, the excitation voltage of the regulation coil can be further adjusted based on the peak-to-peak value of the second discharge current and the second preset ratio. This process is similar to adjusting the excitation voltage of the regulation coil based on the peak-to-peak value of the first discharge current and the second preset ratio, which will not be elaborated here. On the contrary, assume that the average value of the second discharge current is 0.4 A and the peak-to-peak value of the first discharge current is 0.45 A. When the third preset ratio is 50%, since the difference between the peak-to-peak value of the second discharge current and the average value of the second discharge current is 0.45 - 0.4, that is, 0.05. Since 0.05 is less than the third current reference value of 0.2 A. At this time, it indicates that the discharge current oscillation or anode voltage oscillation of the Hall thruster has been effectively suppressed, so the adjustment of the excitation voltage of the regulation coil can be stopped.

[0054] In some embodiments, if the peak-to-peak value of the second discharge current is greater than the peak-to-peak value of the first discharge current, it indicates that during the regulation process, the current direction of the regulation coil is incorrect, which enhances the discharge current oscillation or anode voltage oscillation of the Hall thruster. At this time, the current direction of the regulation coil can be changed.

[0055] Refer to Figures 10 to 12 . Figure 10 It is a schematic diagram of the magnetic field distribution in the discharge region under the rated operating conditions of the Hall thruster provided by some embodiments of the present application. Figure 11 It is a schematic diagram of the magnetic field distribution in the discharge region after the first regulation provided by some embodiments of the present application. Figure 12 It is a schematic diagram of the magnetic field distribution in the discharge region after the second regulation provided by some embodiments of the present application. It can be seen from Figures 10 to 12 that the magnetic field distribution in the discharge region is gradually changing.

[0056] Refer to Figures 13 to 15 . Figure 13 It is for Figure 10 the discharge current schematic diagram of the Hall thruster in Figure 14 It is for Figure 11 the discharge current schematic diagram of the Hall thruster in Figure 15 It is for Figure 12 the discharge current schematic diagram of the Hall thruster in Figures 13 to 15 It can be seen that after multiple regulations, the discharge current oscillation situation of the Hall thruster has been effectively suppressed.

[0057] Based on the above Hall thruster, the present application further provides a Hall propulsion system. Referring to Figure 16 , it is a schematic diagram of the modules of the Hall propulsion system 400 provided for some embodiments of the present application. Figure 16 In the figure, the Hall propulsion system 400 includes a gas storage and mass flow rate control unit 41, a control and acquisition unit 42, a power processing unit 43, and a Hall thruster 44. Among them, the Hall thruster 44 can be one of the above Hall thrusters 100, 200, 300. The power processing unit 43 may include power devices or switching devices such as the above first power supply P1, second power supply P2, third power supply P3, first switch K1, and second switch K2. The gas storage and mass flow rate control unit 41 is mainly used to store the working medium required for the operation of the Hall accelerator and the hollow cathode, and to step down the high-pressure stored working medium and reasonably distribute it through a reasonable flow rate control structure. The control and acquisition unit 42 is used to collect the telemetry data and parameters of the Hall thruster 44. At the same time, it controls the gas storage and mass flow rate control unit 41 and the power processing unit 43 to adjust the output power and the working medium mass flow rate of the Hall thruster 44. In addition, the control and acquisition unit 42 can also be used to communicate with the space satellite. In this way, it can receive the total command of the space satellite and feedback the current state of the Hall thruster 44 to the space satellite.

[0058] The above has introduced in detail the Hall thruster and the excitation method of the Hall thruster provided by the present application. Specific examples are used in this article to elaborate on the principle and implementation manner of the present application. The description of the above embodiments is only used to help understand the method and its core idea of the present application. It should be noted that for those of ordinary skill in the art in this technical field, without departing from the principle of the present application, several improvements and modifications can be made to the present application, and these improvements and modifications also fall within the protection scope of the claims of the present application.

Claims

1. A Hall thruster, characterized in that, The Hall thruster includes: A hollow cathode for emitting electrons; A Hall accelerator including an anode, a discharge region, a regulation coil, a first excitation coil and a second excitation coil connected in series. The first excitation coil and the second excitation coil are used to generate a first magnetic field, and the first magnetic field is at least distributed in the discharge region. The anode attracts the electrons emitted by the hollow cathode into the magnetic field of the discharge region for ionization and generates a discharge current. The regulation coil is used to generate a second magnetic field, and the second magnetic field is used to adjust the magnetic field distribution in the discharge region. The excitation coils and the regulation coil are deployed in a non-series manner, and the excitation power supplies of the excitation coils and the regulation coil are different; A first power supply, one end of which is connected to the anode, and the other end of which is connected to the first excitation coil and the second excitation coil connected in series; A second power supply, one end of which is connected to the hollow cathode, and the other end of which is connected to the first power supply through the first excitation coil and the second excitation coil; A third power supply, one end of which is connected to the hollow cathode through a first switch and to the regulation coil through a second switch, and the other end of which is connected to the first power supply and the second power supply.

2. The Hall thruster according to claim 1, wherein The hollow cathode includes an emitter, a keeper and a heater. One end of the second power supply is connected to the keeper, and one end of the third power supply is connected to the heater through the first switch; Wherein, when the first switch is closed, the third power supply is used to excite the heater to heat the emitter, so that after the emitter reaches the electron emission temperature, initial electrons are generated; The second power supply is used to excite the keeper, so that the initial electrons act on the gas and trigger the discharge of the hollow cathode. During the discharge process of the hollow cathode, the hollow cathode emits electrons externally.

3. The Hall thruster according to claim 1, characterized in that, In the case where the magnetic field distribution in the discharge region needs to be adjusted, the second switch is closed, and the third power supply is used to excite the regulation coil, so that the regulation coil generates the second magnetic field.

4. The Hall thruster according to claim 1, characterized in that, The Hall thruster includes a plurality of regulation coils, and the second switch includes a plurality of sub-switches. The plurality of regulation coils correspond to the plurality of sub-switches one by one, and each regulation coil is connected to the third power supply through the corresponding sub-switch.

5. A method for exciting a Hall thruster according to any one of claims 1 to 4, characterized in that, The method includes: Inputting a working medium into the hollow cathode; When the flow rate of the working medium reaches a steady state, controlling the first switch to close and exciting the hollow cathode through the third power supply, so that the hollow cathode generates initial electrons; When the initial electrons are generated, exciting the hollow cathode through the second power supply, so that the initial electrons act on the working medium and trigger the discharge of the hollow cathode; When the discharge of the hollow cathode is successful, exciting the first excitation coil and the second excitation coil through the first power supply, so that the first excitation coil and the second excitation coil generate a first magnetic field.

6. The method according to claim 5, wherein After exciting the hollow cathode, the method further includes: When the discharge of the hollow cathode reaches a self-sustaining state, control the first switch to change from the closed state to the open state, and control the third power supply to stop exciting the hollow cathode; After generating a discharge current in the Hall accelerator, control the second power supply to stop exciting the hollow cathode.

7. The method according to claim 5, wherein After exciting the first excitation coil and the second excitation coil, the method further includes: Obtain the average value of the first discharge current and the peak-to-peak value of the first discharge current of the Hall thruster, where the peak-to-peak value of the first discharge current is the difference between the highest amplitude and the lowest amplitude of the first discharge current of the Hall thruster; Based on the peak-to-peak value of the first discharge current and the average value of the first discharge current, determine whether the oscillation amplitude of the discharge current of the Hall thruster is lower than the target amplitude; If the oscillation amplitude of the discharge current is not lower than the target amplitude, control the second switch to close, and excite the regulation coil through the third power supply to adjust the magnetic field distribution in the discharge area of the Hall thruster. When the magnetic field distribution in the discharge area changes, the discharge current of the Hall thruster changes.

8. The method according to claim 7, wherein The determining whether the oscillation amplitude of the discharge current of the Hall thruster is lower than the target amplitude based on the peak-to-peak value of the first discharge current and the average value of the first discharge current includes: Multiply the average value of the first discharge current by a first preset ratio to obtain a first reference current value; If the difference between the peak-to-peak value of the first discharge current and the average value of the first discharge current is greater than the first reference current value, determine that the oscillation amplitude of the discharge current of the Hall thruster is not lower than the target amplitude; And, the exciting the regulation coil of the Hall thruster includes: Multiply the peak-to-peak value of the first discharge current by a second preset ratio to obtain a second current reference value; Determine the excitation voltage of the regulation coil according to the second current reference value, and excite the regulation coil according to the excitation voltage.

9. The method according to claim 8, wherein After exciting the regulation coil according to the second current reference value, the method further includes: Obtain the average value of the second discharge current and the peak-to-peak value of the second discharge current of the Hall thruster, where the peak-to-peak value of the second discharge current is the difference between the highest amplitude and the lowest amplitude of the second discharge current of the Hall thruster; If the peak-to-peak value of the second discharge current is less than the peak-to-peak value of the first discharge current, multiply the average value of the second discharge current by a third preset ratio to obtain a third current reference value; If the difference between the peak-to-peak value of the second discharge current and the average value of the second discharge current is greater than the third current reference value, adjust the excitation voltage of the regulation coil; If the difference between the peak-to-peak value of the second discharge current and the average value of the second discharge current is not greater than the third current reference value, stop adjusting the excitation voltage of the regulation coil.

10. The method according to claim 9, characterized in that, The method further includes: If the peak-to-peak value of the second discharge current is greater than the peak-to-peak value of the first discharge current, change the current direction of the regulation coil.

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