Hall thrusters and their excitation methods

Abstract

This application discloses a Hall thruster and its excitation method, relating to the field of power device technology. On one hand, this application adds a control coil to the Hall thruster, generating a second magnetic field to adjust the magnetic field distribution in the discharge region, effectively suppressing discharge current oscillations or anode voltage oscillations 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. Simultaneously, the first, second, and third power supplies are connected and can share a common ground. This significantly reduces the number of power supplies required for the Hall thruster, thereby effectively reducing its cost while adding a control coil.

Description

Technical Field

[0001] This application relates to the field of power device technology, and in particular to Hall thrusters and excitation methods for Hall thrusters. Background Technology

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

[0003] During the lifespan of a Hall thruster, its performance may change as its service time increases. To address these performance changes, modifications to the Hall thruster are necessary. These modifications inevitably increase the cost of the Hall thruster. However, to meet the low-cost requirements of commercial satellites, cost reduction and a certain degree of controllability are needed for the Hall thruster. Summary of the Invention

[0004] This application provides a Hall thruster and a Hall thruster excitation method to at least solve the problems of high cost and poor controllability of Hall thrusters in related technologies.

[0005] This application provides a Hall thruster, the Hall thruster comprising:

[0006] Hollow cathode, used to emit electrons;

[0007] A Hall accelerator includes an anode, a discharge region, a control coil, and 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, which is at least distributed in the discharge region. The anode attracts electrons emitted by the hollow cathode to the magnetic field of the discharge region for ionization and to generate a discharge current. The control coil is used to generate a second magnetic field, which is used to adjust the magnetic field distribution in the discharge region. The excitation coil and the control coil are deployed in a non-series manner, and the excitation coil and the control coil have different excitation power supplies.

[0008] 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.

[0009] A second power source, one end of which is connected to the hollow cathode, and the other end of which is connected to the first power source through the first excitation coil and the second excitation coil.

[0010] A third power source, one end of which is connected to the hollow cathode via a first switch and to the control coil via a second switch, and the other end of which is connected to the first power source and the second power source.

[0011] This application provides an excitation method for the above-mentioned Hall thruster, the method comprising:

[0012] A working fluid is introduced into the hollow cathode;

[0013] When the flow rate of the working fluid reaches a steady state, the first switch is closed and the hollow cathode is excited by the third power supply so that the hollow cathode generates initial electrons.

[0014] When the initial electrons are generated, the hollow cathode is excited by a second power source so that the initial electrons interact with the working fluid and trigger the hollow cathode to discharge.

[0015] If 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.

[0016] In some embodiments of this application, on the one hand, a control coil is added to the Hall thruster. This control coil generates a second magnetic field, adjusting the magnetic field distribution in the discharge region, effectively suppressing discharge current oscillations or anode voltage oscillations and ensuring stable performance of the Hall thruster. 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. Simultaneously, the first, second, and third power supplies are connected and can share a common ground. This significantly reduces the number of power supplies required for the Hall thruster, thereby effectively reducing the cost and improving controllability of the Hall thruster while adding a control coil. Attached Figure Description

[0017] To more clearly illustrate the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 A schematic diagram of the etching of the discharge channels of some Hall thrusters over time;

[0019] Figure 2 This is a schematic diagram showing the change of discharge current of some Hall thrusters over time.

[0020] Figure 3 This is a schematic diagram showing the change of anode voltage of some Hall thrusters over time.

[0021] Figure 4 Schematic diagram of a Hall thruster provided for some embodiments of this application;

[0022] Figure 5 for Figure 4 A schematic diagram of the magnetic field guidance of the Hall thruster in the diagram;

[0023] Figure 6 A schematic diagram of a Hall thruster provided for another embodiment of this application;

[0024] Figure 7 A schematic diagram of a Hall thruster provided for another embodiment of this application;

[0025] Figure 8 A flowchart illustrating the excitation method provided for some embodiments of this application;

[0026] Figure 9 A schematic flowchart illustrating the regulation of the discharge current oscillation of a Hall thruster, provided for some embodiments of this application;

[0027] Figure 10 This application provides schematic diagrams of the magnetic field distribution in the discharge region under rated operating conditions of a Hall thruster, for some embodiments thereof.

[0028] Figure 11 This application provides a schematic diagram of the magnetic field distribution in the discharge region after the first adjustment, as shown in some embodiments of the present application.

[0029] Figure 12 This application provides a schematic diagram of the magnetic field distribution in the discharge region after a second adjustment, as shown in some embodiments of the present application.

[0030] Figure 13 for Figure 10 A schematic diagram of the discharge current of the Hall thruster in the diagram;

[0031] Figure 14 for Figure 11 A schematic diagram of the discharge current of the Hall thruster in the diagram;

[0032] Figure 15 for Figure 12 A schematic diagram of the discharge current of the Hall thruster in the diagram;

[0033] Figure 16 A schematic diagram of a Hall thruster system provided for some embodiments of this application. Detailed Implementation

[0034] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of this application.

[0035] It should be noted that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. The terms "installed," "connected," and "linked" should be interpreted broadly, for example, they can be fixed connections, detachable connections, or integral connections; they can be mechanical connections or electrical connections; they can be direct connections or indirect connections through an intermediate medium; they can be internal connections between two elements. The terms "parallel," "perpendicular," and "equal" include the described situation and situations similar to the described situation, the range of which is within an acceptable deviation range, wherein the acceptable deviation range is determined by those skilled in the art taking into account the measurement under discussion and the error associated with the measurement of a particular quantity (i.e., the limitations of the measurement system). For example, "parallel" includes absolute parallelism and approximate parallelism, where an acceptable deviation range for approximate parallelism can be, for example, within 5°; "perpendicular" includes absolute perpendicularity and approximate perpendicularity, where an acceptable deviation range for approximate perpendicularity can also be, for example, within 5°. "Equal" includes absolute equality and approximate equality, where an acceptable deviation range for approximate equality can be, for example, a difference between the two equal items being less than or equal to 5% of either one. Those skilled in the art will understand the specific meaning of the above terms in this application based on the specific circumstances.

[0036] During the lifespan of a Hall thruster, its performance may change as the usage time increases. For example, refer to [reference needed]. Figure 1This diagram illustrates the etching of the discharge channel of a Hall thruster over time. Taking a Hall thruster used for 1x hours as an example, after 1x hours of use, the abc region to the right of the dashed line in its discharge channel will be etched away. Based on a similar principle, it can be seen that as the usage time of the Hall thruster increases, the etched area of ​​the discharge channel gradually increases. With the increase in the etched area of ​​the discharge channel, the discharge current and anode voltage of the Hall thruster may shift towards more severe operating conditions. For example, refer to... Figure 2 and Figure 3 . Figure 2 This is a schematic diagram showing the change in discharge current of some Hall thrusters over time. Figure 3 This is a schematic diagram illustrating the variation of anode voltage of some Hall thrusters over usage time. Figure 2 and Figure 3 It can be seen that the discharge current and anode voltage of the Hall thruster oscillated as the usage time increased. 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 stabilize again.

[0037] In view of this, this application provides a modified Hall thruster that supports adjustment of the magnetic field distribution in the discharge region of the Hall thruster, while effectively controlling the cost of the Hall thruster.

[0038] See also Figure 4 The diagram below is a schematic diagram of a Hall thruster 100 provided for some embodiments of this application. Figure 1 In the process, 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.

[0039] Hollow cathode 101 is used to emit electrons. Hall accelerator 102 includes anode 5, discharge region 15, control coil 10, and 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, which is at least distributed in the discharge region 15. Anode 5 attracts electrons emitted by hollow cathode 101 to the magnetic field of discharge region 15 for ionization and to generate discharge current. Control coil 10 is used to generate a second magnetic field, which is used to adjust the magnetic field distribution in discharge region 15.

[0040] Specifically, in this embodiment, the Hall thruster 100 further includes a first magnetic pole 1, a second magnetic pole 2, a magnetically conductive base plate 3, a first magnetic screen 6, and a second magnetic screen 7. After the first excitation coil 8 and the second excitation coil 9 are excited by the excitation power supply, current can be generated in the first excitation coil 8 and the second excitation coil 9, thereby generating a first magnetic field. The first magnetic pole 1, the second magnetic pole 2, the magnetically conductive base plate 3, the discharge channel 4, the first magnetic screen 6, and the second magnetic screen 7 can serve as magnetic circuit construction components. The first magnetic field generated by the first excitation coil 8 and the second excitation coil 9, after being guided by the first magnetic pole 1, the second magnetic pole 2, the discharge channel 4, the first magnetic screen 6, the second magnetic screen 7, and the magnetically conductive base plate 3, is at least distributed in the discharge area 15 enclosed by the discharge channel 4, forming a closed path (i.e., a magnetic circuit) of the magnetic field.

[0041] For ease of understanding, please refer to the following: Figure 5 ,for Figure 4 The diagram illustrates the magnetic field guidance of the Hall thruster 100. For example, when the second excitation coil 9 is energized, a first magnetic field is generated around the second magnetic pole 2 and in the discharge region 15. This first magnetic field around the second magnetic pole 2 passes through the discharge channel 4 and, guided by the magnetically conductive base plate 3, reaches the first magnetic pole 1, and then from the first magnetic pole 1 to the second magnetic pole 2, thus forming a closed path for the magnetic field. During the process of the first magnetic field moving from the first magnetic pole 1 to the second magnetic pole 2, the first magnetic screen 6 and the second magnetic screen 7 can capture the first magnetic field in the discharge region 15, thereby reducing magnetic field leakage and improving magnetic field utilization. Adjusting the magnetic screen parameters of the first magnetic screen 6 and the second magnetic screen 7 can adjust the magnetic field distribution in the discharge region 15. These magnetic screen parameters include, but are not limited to, the position and shape of the magnetic screen.

[0042] 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 area 15. The first magnetic field around the first magnetic pole 1 will pass through the discharge channel 4 and be guided by the magnetic base plate 3 to reach the second magnetic pole 2, and then from the second magnetic pole 2 to the first magnetic pole 1.

[0043] Guided by the magnetic circuit construction components, a negative gradient radial magnetic field distribution can be formed along the axial direction AB of the discharge region 15. The anode 5 attracts electrons emitted from the hollow cathode 101 into the magnetic field of the discharge region 15 for ionization and to generate a discharge current. Specifically, on one hand, the anode 5 can act as a high-potential end of the discharge region 15, attracting electrons emitted from the hollow cathode 101 to move along the anode 5. At the end CD of the discharge region 15 (i.e., the outlet of the discharge region 15), electrons can be captured by the magnetic field in the discharge region 15, thus entering the discharge region 15. On the other hand, the anode 5 can act as a gas distributor, filling the discharge region 15 with gas (such as xenon, krypton, etc.). The gas in the discharge region 15 can collide with electrons whose energy exceeds the ionization energy of the gas, generating plasma; this process is ionization. During ionization, due to the energy loss of electrons, a positive gradient electric field is formed along the axial direction AB of the discharge region 15; that is, the farther away from the anode 5, the stronger the electric field. A positive gradient electric field can be used to accelerate and eject ions generated by ionization from the end CD of the discharge region 15, thereby generating thrust and a discharge current. Typically, the magnitude of the discharge current directly affects the rate and intensity of ionization. When the discharge current increases, it indicates that more electrons are accelerated and participate in the ionization process, thus generating more ions. These ions, under the influence of the electric field, are accelerated and ejected from the end CD of the discharge region 15, generating thrust. Therefore, to a certain extent, increasing the discharge current can increase the thrust of the Hall thruster 100. However, when the discharge current increases to a certain level, ionization tends to saturate, at which point further increases in discharge current will no longer increase the thrust of the Hall thruster 100.

[0044] If the oscillation amplitude of the discharge current or anode voltage of the Hall thruster 100 is not lower than the target amplitude, the control coil 10 can be used to generate a second magnetic field. This second magnetic field is used to adjust the magnetic field distribution in the discharge region 15 so that the oscillation amplitude of the discharge current or anode voltage is lower than the target amplitude. Specifically, the second magnetic field can also be distributed at least in the discharge region 15. The first and second magnetic fields in the discharge region 15 are superimposed on each other, which can adjust the magnetic field distribution in the discharge region 15. When the magnetic field distribution in the discharge region 15 changes, the electronic behavior (e.g., electron velocity) in the Hall thruster 100 can change, thereby effectively suppressing the oscillation of the discharge current or anode voltage of the Hall thruster 100.

[0045] In this embodiment, the excitation coils 8 and 9 and the control coil 10 are deployed in a non-series manner, and their excitation power supplies are different. For example, the excitation coils 8 and 9 can be excited by a first power supply, while the control coil 10 can be excited by a third power supply. This allows for independent control of the first magnetic field generated by the excitation coils 8 and 9 and the second magnetic field generated by the control coil 10, thereby improving adjustment flexibility. For instance, the current direction of the excitation coils 8 and 9 can be opposite to the current direction of the control coil 10, making the excitation direction of the excitation coils 8 and 9 opposite to that of the control coil 10. Conversely, if the excitation coils 8 and 9 and the control coil 10 are deployed in series, the current direction of the excitation coils 8 and 9 needs to be the same as that of the control coil 10. This would require the excitation direction of the excitation coils 8 and 9 to be opposite to that of the control coil 10, making it difficult to flexibly adjust the magnetic field distribution in the discharge region 15 according to actual needs.

[0046] Because a control coil 10 is added to the Hall thruster 100, an additional excitation power supply for the control coil 10 is also required, which undoubtedly increases the cost of the Hall thruster 100. Therefore, this application proposes the following power connection design:

[0047] 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 first excitation coil 8 and the second excitation coil 9 connected in series. Specifically, the positive terminal of the first power supply P1 is connected to the anode 5, and the negative terminal of the first power supply P1 is connected to the first excitation coil 8 and the second excitation coil 9 connected in series, thereby realizing the series connection of the anode 5, the first excitation coil 8, and the second excitation coil 9.

[0048] 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 terminal of the second power supply P2 is connected to the hollow cathode 101, and the negative terminal of the second power supply P2 is connected to the negative terminal 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.

[0049] One end of the third power supply P3 is connected to the hollow cathode 101 via the first switch K1 and to the control coil 10 via the second switch K2. 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 terminal of the third power supply P3 is connected to the hollow cathode 101 via the first switch K1 and to the control coil 10 via the second switch K2, and the negative terminal of the third power supply P3 is connected to the negative terminals 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.

[0050] In this embodiment, the hollow cathode 101 may include a contact 11, an emitter 12, a heater 13, and a cathode tube 14. One end of the second power supply P2 is connected to the contact 11, and one end of the third power supply P3 is connected to the heater 13 via a first switch K1. Specifically, the positive terminal of the second power supply P2 is connected to the contact 11, and the positive terminal of the third power supply P3 is connected to the heater 13 via the first switch K1. 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 the emitter 12 reaches the electron emission temperature and generates initial electrons. The second power supply P2 is used to excite the contact 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 to the outside.

[0051] Specifically, the cathode tube 14 can be a hollow structure with a variable diameter, which can serve as a passage for gas (such as xenon, krypton, etc.). An emitter 12 is housed within the large-diameter hollow structure. After the heater 13 is excited by the third power supply P3, the emitter 12 can be heated. Once the temperature of the emitter 12 reaches the electron emission temperature, initial electrons can be emitted. At this time, after filling the hollow structure of the cathode tube 14 with gas and exciting the contact 11, a primary discharge and plasma generation can first occur in the end slit region between the contact 11 and the cathode tube 14. Subsequently, the plasma in the end slit region can migrate to the hollow region of the emitter 12, and maintain continuous plasma operation in the hollow region through electron bombardment or ion bombardment, thereby creating a self-consistent plasma potential drop between the emitter 12 and the contact 11, forming a discharge in the hollow cathode 101. After the discharge is formed in the hollow cathode 101, the contact 11 can draw electrons from the hollow region of the emitter 12 to the outside of the hollow cathode 101, thereby achieving the purpose of the hollow cathode 101 emitting electrons.

[0052] When it is necessary to adjust the magnetic field distribution in the discharge region 15, 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.

[0053] In summary, in some embodiments of this 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 the discharge current oscillation or anode voltage oscillation of the Hall thruster 100 and ensuring the 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 the first power supply P1, and the control coil 10 and the hollow cathode 101 share the third power supply P3. At the same time, the first power supply P1, the second power supply P2, and the third power supply P3 are connected and can use a common ground. In this way, the number of power supplies in the Hall thruster 100 can be greatly reduced, thereby effectively reducing the cost of the Hall thruster 100 while increasing the control coil 10.

[0054] 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 this configuration, 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 arrangement 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.

[0055] In other embodiments, the control coil 10 may include a first control coil and a second control coil, with the first excitation coil 8 coaxial with the first control coil and the second excitation coil 9 coaxial with the second control coil. Thus, the second magnetic field generated by the first control coil can be primarily 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 control coil can be primarily used to adjust the magnetic field distribution of the first magnetic field generated by the first excitation coil 9. Adjusting the magnetic field distribution in the discharge region 15 using at least two control coils yields better results and provides greater flexibility in the adjustment method.

[0056] Furthermore, if the Hall thruster 100 includes multiple control coils 10 (e.g., a first control coil and a second control coil), the second switch K2 can include multiple sub-switches, with each control coil 10 corresponding to one of the sub-switches. Each control coil 10 is connected to the third power supply P3 through its corresponding sub-switch. In this way, based on the opening or closing of the sub-switches, each control coil 10 can be controlled individually, thereby adjusting the magnetic field distribution in the discharge region 15, making the adjustment method more flexible.

[0057] In some embodiments, for a coaxial target excitation coil and a target control coil, the target control coil may be located radially outside the target excitation coil, or the target excitation coil may be located radially outside the target control coil. When the target control coil is located radially outside the target excitation coil, the radius of the target control coil is larger than the radius of the target excitation coil; when the target excitation coil is located radially outside the target control coil, the radius of the target excitation coil is larger than the radius of the target control coil. For example... Figure 4 In this context, the target control coil is located radially outside the target excitation coil. The principle behind the target excitation coil being located radially outside the target control coil is the opposite of that of the target control coil being located radially outside the target excitation coil, and will not be elaborated here.

[0058] In other embodiments, the target control coil is located on one side of the target excitation coil along the axial direction of the target excitation coil and the target control coil. For ease of understanding, please refer to the following... Figure 6 This is a schematic diagram of a Hall thruster 200 provided in another embodiment of this application. The Hall thruster 200 is basically similar in principle to the Hall thruster 100, the main difference being that the control coil 20 (i.e., the target control coil) and the first excitation coil 28 (i.e., the target excitation coil) are coaxial, and the control coil 20 is located on one side of the first excitation coil 28.

[0059] See also Figure 7 This is a schematic diagram of a Hall thruster 300 provided in another embodiment of this application. The Hall thruster 300 is basically similar in principle to the Hall thruster 100, with the main difference being that... Figure 7 In this configuration, the control coil 30 is not coaxial with the first excitation coil 38 or the second excitation coil 39, but is located on the side of the anode 35 away from the discharge region 315.

[0060] In practice, the control coil can be deployed using one of the above-mentioned deployment methods as needed, and this application does not impose any restrictions on this.

[0061] Correspondingly, this application also provides an excitation method for any of the above-mentioned Hall thrusters. (See also...) Figure 8 This is a flowchart illustrating the excitation method provided in some embodiments of this application. Figure 8 In this context, the incentive method includes the following steps:

[0062] Step 801: Input the working fluid into the hollow cathode.

[0063] The working fluid is the gas required for the Hall thruster to operate, such as xenon or krypton.

[0064] Step 802: When the flow rate of the working fluid reaches a stable state, control the first switch to close and excite the hollow cathode through the third power supply to generate initial electrons in the hollow cathode.

[0065] Step 803: In the case of generating initial electrons, the hollow cathode is excited by the second power supply so that the initial electrons interact with the working fluid and trigger the hollow cathode to discharge.

[0066] Step 804: If 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.

[0067] Furthermore, after stimulating the hollow cathode, when the discharge of the hollow cathode reaches a self-sustaining state, the first switch is controlled to change from a closed state to an open state, and the third power supply is controlled to stop stimulating the hollow cathode. After a discharge current is generated in the Hall accelerator, the second power supply is controlled to stop stimulating the hollow cathode. This reduces energy waste.

[0068] For ease of understanding, please refer to the following: Figure 9 The diagram below illustrates a process for regulating the discharge current oscillation of a Hall thruster, as provided in some embodiments of this application. Figure 9 The method includes the following steps:

[0069] Step S901: Obtain the average value of the first discharge current and the peak-to-peak value of the first discharge current of the Hall thruster.

[0070] Specifically, the peak-to-peak value of the first discharge current is the difference between the highest and lowest amplitudes of the first discharge current of the Hall thruster. The discharge current of the Hall thruster at multiple time points within a recent preset time period can be obtained. Based on the discharge currents at these multiple time points, the average value and peak-to-peak value of the first discharge current of the Hall thruster within the recent preset time period are obtained. For example, the discharge current of the Hall thruster at multiple time points within the last 5 milliseconds can be obtained. Averaging the discharge currents at these multiple time points yields the average value of the first discharge current. The difference between adjacent highest and lowest amplitudes among the discharge currents at these multiple time points can be used as the peak-to-peak value of the first discharge current.

[0071] 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.

[0072] In this embodiment, the first average discharge current value can be multiplied 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, 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%. Assuming the average value of the first discharge current is 0.5 amps and the peak-to-peak value of the first discharge current is 1.2 amps, 0.5 can be multiplied by 80% to obtain a 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, i.e., 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. Conversely, if the peak-to-peak value of the first discharge current is 0.7 amps, 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, i.e., 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.

[0073] Of course, the method for determining the reference current value is not limited to the method described above. 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.

[0074] In the above embodiments, the first reference current value is dynamically generated based on the average value of the first discharge current, which can improve the accuracy of the judgment.

[0075] In step S903, if the oscillation amplitude of the discharge current is not lower than the target amplitude, the control coil of the Hall thruster is excited to adjust the magnetic field distribution in the discharge region of the Hall thruster. When the magnetic field distribution in the discharge region changes, the discharge current of the Hall thruster changes.

[0076] 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. Based on this second current reference value, the excitation voltage of the control coil is determined, and the control coil is then energized according to this voltage. For example, the second preset ratio can be 20%. Assuming the peak-to-peak value of the first discharge current is 1 amp, multiplying it by the second preset ratio yields a second current reference value of 0.2 amps. Based on this second current reference value of 0.2 amps, the excitation voltage of the control coil can be controlled to generate a current of 0.2 amps.

[0077] The excitation voltage of the control coil can be determined by the peak-to-peak value of the first discharge current, which can effectively adjust the magnetic field distribution in the discharge region.

[0078] In some embodiments, after energizing the control coil according to the second current reference value, the method of this application may further include:

[0079] The average value of the second discharge current and the peak-to-peak value of the second discharge current of the Hall thruster are obtained. The peak-to-peak value of the second discharge current is the difference between the highest and lowest amplitudes of the second discharge current of the Hall thruster.

[0080] If the peak-to-peak value of the second discharge current is less than the peak-to-peak value of the first discharge current, then the average value of the second discharge current is multiplied by the third preset ratio to obtain the third current reference value.

[0081] 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 reference value of the third current, the excitation voltage of the control coil shall be further adjusted.

[0082] 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 reference value of the third current, then stop adjusting the excitation voltage of the control coil.

[0083] The principle of obtaining the average value of the second discharge current and the peak value of the second discharge current is similar to that of obtaining the average value of the first discharge current and the peak value of the first discharge current, and will not be elaborated here.

[0084] For example, the third preset ratio can be 50%. Assume the average value of the second discharge current is 0.4 amps, and the peak-to-peak value of the first discharge current is 0.7 amps. Multiplying the average value of the second discharge current by the third preset ratio yields a third current reference value of 0.2 amps. The difference between the peak-to-peak value and the average value of the second discharge current is 0.7 - 0.4, or 0.3. Since 0.3 is greater than the third current reference value of 0.2 amps, the excitation voltage of the control 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 control coil based on the peak-to-peak value of the first discharge current and the second preset ratio, and will not be elaborated here. Conversely, assuming the average value of the second discharge current is 0.4 amps, and the peak-to-peak value of the first discharge current is 0.45 amps. With a third preset ratio of 50%, the difference between the peak-to-peak value and the average value of the second discharge current is 0.45 - 0.4, or 0.05. Since 0.05 is less than the third current reference value of 0.2 amps. At this point, 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 control coil can be stopped.

[0085] 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 the current direction of the control coil is incorrect during the control process, which enhances the discharge current oscillation or anode voltage oscillation of the Hall thruster. In this case, the current direction of the control coil can be changed.

[0086] See also Figures 10 to 12 . Figure 10 This is a 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 this application. Figure 11 This is a schematic diagram of the magnetic field distribution in the discharge region after the first adjustment, provided for some embodiments of this application. Figure 12 This is a schematic diagram of the magnetic field distribution in the discharge region after a second adjustment, provided for some embodiments of this application. From... Figures 10 to 12 It can be seen that the magnetic field distribution in the discharge region is gradually changing.

[0087] See also Figures 13 to 15 . Figure 13 for Figure 10 A schematic diagram of the discharge current of the Hall thruster in the diagram. Figure 14 for Figure 11 A schematic diagram of the discharge current of the Hall thruster in the diagram. Figure 15 for Figure 12 A schematic diagram of the discharge current of the Hall thruster in the image. Figures 13 to 15 It can be seen that, after multiple adjustments, the discharge current oscillation of the Hall thruster has been effectively suppressed.

[0088] Based on the aforementioned Hall thruster, this application also provides a Hall propulsion system. (See also...) Figure 16 The diagram below shows a module schematic of a Hall thruster system 400 provided in some embodiments of this application. Figure 16 In this system, the Hall thruster 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. The Hall thruster 44 can be one of the Hall thrusters 100, 200, and 300 mentioned above. The power processing unit 43 can include power devices or switching devices such as the first power supply P1, the second power supply P2, the third power supply P3, the first switch K1, and the second switch K2. The gas storage and mass flow rate control unit 41 is mainly used to store the working fluid required for the operation of the Hall accelerator and the hollow cathode, and to depressurize the high-pressure stored working fluid and distribute it rationally through a reasonable flow rate control structure. The control and acquisition unit 42 is used to acquire telemetry data and parameters of the Hall thruster 44, and simultaneously control the gas storage and mass flow rate control unit 41 and the power processing unit 43 to adjust the output power and working fluid 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, so that it can receive the general command of the space satellite and feed back the current status of the Hall thruster 44 to the space satellite.

[0089] The Hall thruster and its excitation method provided in this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the embodiments above are merely for the purpose of helping to understand the method and its core ideas. It should be noted that those skilled in the art can make various improvements and modifications to this application without departing from its principles, and these improvements and modifications also fall within the protection scope of the claims of this application.

Claims

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

2. The Hall thruster according to claim 1, characterized in that, The hollow cathode includes an emitter, a contact, and a heater. One end of the second power supply is connected to the contact, and one end of the third power supply is connected to the heater through the first switch. When the first switch is closed, the third power source is used to excite the heater to heat the emitter so that the emitter reaches the electron emission temperature and generates initial electrons. The second power source is used to excite the contact so that the initial electrons interact with the gas and trigger the hollow cathode to discharge. During the discharge process of the hollow cathode, the hollow cathode emits electrons to the outside.

3. The Hall thruster according to claim 1, characterized in that, When it is necessary to adjust the magnetic field distribution in the discharge region, the second switch is closed, and the third power supply is used to excite the control coil so that the control coil generates the second magnetic field.

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

5. An excitation method for the Hall thruster according to any one of claims 1 to 4, characterized in that, The method includes: A working fluid is introduced into the hollow cathode; When the flow rate of the working fluid reaches a steady state, the first switch is closed and the hollow cathode is excited by the 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 source so that the initial electrons interact with the working fluid and trigger the hollow cathode to discharge. If 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.

6. The method according to claim 5, characterized in that, After stimulating the hollow cathode, the method further includes: When the discharge of the hollow cathode reaches a self-sustaining state, the first switch is controlled to change from a closed state to an open state, and the third power supply is controlled to stop energizing the hollow cathode. After a discharge current is generated in the Hall accelerator, the second power supply is controlled to stop stimulating the hollow cathode.

7. The method according to claim 5, characterized in that, After energizing the first excitation coil and the second excitation coil, the method further includes: The average value of the first discharge current and the peak-to-peak value of the first discharge current of the Hall thruster are obtained, wherein the peak-to-peak value of the first discharge current is the difference between the highest and lowest amplitudes 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, it is determined 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, the second switch is controlled to close, and the control coil is excited by the third power supply to adjust the magnetic field distribution of the discharge region of the Hall thruster. When the magnetic field distribution of the discharge region changes, the discharge current of the Hall thruster changes.

8. The method according to claim 7, characterized in that, The step of 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 and the average value of the first discharge current includes: The first reference current value is obtained by multiplying the average value of the first discharge current by the first preset ratio. 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, then it is determined that the oscillation amplitude of the discharge current of the Hall thruster is not lower than the target amplitude. And, the control coil that excites the Hall thruster includes: Multiply the peak-to-peak value of the first discharge current by the second preset ratio to obtain the second current reference value; The excitation voltage of the control coil is determined according to the second current reference value, and the control coil is excited according to the excitation voltage.

9. The method according to claim 8, characterized in that, After energizing the control coil according to the second current reference value, the method further includes: The average value of the second discharge current and the peak-to-peak value of the second discharge current of the Hall thruster are obtained, wherein the peak-to-peak value of the second discharge current is the difference between the highest and lowest amplitudes 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, then the average value of the second discharge current is multiplied by the third preset ratio to obtain the 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, then the excitation voltage of the control coil is 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, then the adjustment of the excitation voltage of the control coil shall be stopped.

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, then the current direction of the control coil is changed.

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