Hall thruster and control method of Hall thruster

Abstract

This application discloses a Hall thruster and a method for controlling the Hall thruster, relating to the field of power device technology. The Hall thruster of this application includes a hollow cathode and a Hall accelerator. The hollow cathode is used to emit electrons. The Hall accelerator includes an anode, a first excitation coil, a second excitation coil, a discharge channel, and a control coil. The first and second excitation coils are used to generate a first magnetic field, which is distributed at least in the discharge region enclosed by the discharge channel. The anode is used to attract the electrons emitted by the hollow cathode to the magnetic field of the discharge region for ionization and to generate a discharge current. When the oscillation amplitude of the discharge current is not lower than a target amplitude, the control 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 so that the oscillation amplitude of the discharge current is lower than the target amplitude. The excitation power supplies of the excitation coil and the control coil are different. The Hall thruster has a good low-frequency oscillation suppression effect.

Description

Technical Field

[0001] This application relates to the field of power device technology, and in particular to Hall thrusters and methods for controlling 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] Low-frequency oscillations are a common plasma instability phenomenon during the discharge process of Hall thrusters, typically manifested as significant oscillations in the discharge current amplitude within a frequency range of 10–100 kHz. Since the oscillation amplitude of the discharge current can exceed 10%–200% of the average current value, it poses a risk of damage to circuit components; therefore, it is necessary to suppress the low-frequency oscillations of Hall thrusters. Summary of the Invention

[0004] This application provides a Hall thruster and a method for controlling the Hall thruster, in order to at least solve the problem of low-frequency oscillation of the Hall thruster.

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

[0006] Hollow cathode, used to emit electrons;

[0007] A Hall effect accelerator includes an anode, a first excitation coil, a second excitation coil, a discharge channel, and a control coil. The first and second excitation coils generate a first magnetic field, which is distributed at least within a discharge region enclosed by the discharge channel. 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. When the oscillation amplitude of the discharge current is not lower than a target amplitude, the control coil generates a second magnetic field to adjust the magnetic field distribution in the discharge region so that the oscillation amplitude of the discharge current is lower than the target amplitude. The excitation coil and the control coil are deployed in a non-series configuration, and their excitation power supplies are different.

[0008] This application provides a method for controlling the aforementioned Hall thruster, the method comprising:

[0009] 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.

[0010] 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;

[0011] 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 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.

[0012] In some embodiments of this application, a first excitation coil and a second excitation coil are provided in the Hall thruster. The first magnetic field generated by the first and second excitation coils can be distributed at least in the discharge region. This ensures that the ionization process of the Hall thruster proceeds normally, enabling the Hall thruster to generate thrust. Simultaneously, a control coil is provided in the Hall thruster. When the Hall thruster experiences low-frequency oscillations, the second magnetic field generated by the control coil can be used to adjust the magnetic field distribution in the discharge region, thereby adjusting the electron behavior in the Hall thruster and effectively suppressing the low-frequency oscillations of the Hall thruster. Attached Figure Description

[0013] 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.

[0014] Figure 1 Schematic diagram of a Hall thruster provided for some embodiments of this application;

[0015] Figure 2 for Figure 1 A schematic diagram of the magnetic field guidance of the Hall thruster in the diagram;

[0016] Figure 3 A schematic diagram of a Hall thruster provided for another embodiment of this application;

[0017] Figure 4 A schematic flowchart illustrating the control method provided in some embodiments of this application;

[0018] Figure 5 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.

[0019] Figure 6 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.

[0020] Figure 7This 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.

[0021] Figure 8 for Figure 5 A schematic diagram of the discharge current of the Hall thruster in the diagram;

[0022] Figure 9 for Figure 6 A schematic diagram of the discharge current of the Hall thruster in the diagram;

[0023] Figure 10 for Figure 7 A schematic diagram of the discharge current of the Hall thruster in the diagram. Detailed Implementation

[0024] 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.

[0025] 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.

[0026] In some technologies, methods for suppressing low-frequency oscillations in Hall thrusters mainly include active control and passive control. Active control primarily involves controlling discharge parameters such as the discharge voltage, discharge current, and excitation current of the Hall thruster to actively suppress low-frequency oscillations. Passive control mainly involves controlling the size, material, and structure of the discharge channel of the Hall thruster to passively suppress low-frequency oscillations. Active control offers high adjustment flexibility but is generally accompanied by significant changes in operating conditions; that is, during the suppression of low-frequency oscillations, it cannot be guaranteed that the operating state of the Hall thruster will remain within a predetermined range, nor can it guarantee effective suppression of low-frequency oscillations. Passive control primarily addresses low-frequency oscillations in the Hall thruster through hardware-related designs, typically involving one-off designs and lacking flexible adjustability.

[0027] In view of this, this application provides a Hall thruster that can effectively suppress low-frequency oscillations of the Hall thruster, while having high adjustment flexibility and minimal impact on the operating state of the Hall thruster.

[0028] See also Figure 1 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 and a Hall accelerator 102.

[0029] The hollow cathode 101 is used to emit electrons. Specifically, the hollow cathode 101 may include a contact 11, an emitter 12, a heater 13, and a cathode tube 14. The cathode tube 14 is a hollow structure with a variable diameter, which can serve as a passageway for gas (such as xenon or krypton). The emitter 12 is housed within the large-diameter hollow structure. After the heater 13 is activated, 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 activating the contact 11, a primary discharge and plasma generation 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 flow in the hollow region through electron bombardment or ion bombardment, creating a self-consistent plasma potential drop between the emitter 12 and the contact 11, thus 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.

[0030] The Hall effect accelerator 102 includes an anode 5, a first excitation coil 8, a second excitation coil 9, a discharge channel 4, and a control coil 10. The discharge channel 4 can enclose a discharge region 15. When the first excitation coil 8 and the second excitation coil 9 are energized, a first magnetic field can be generated. The first magnetic field is distributed at least within the discharge region 15 enclosed by the discharge channel 4.

[0031] 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.

[0032] For ease of understanding, please refer to the following: Figure 2 ,for Figure 1 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.

[0033] 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.

[0034] It should be noted that the excitation directions of the first excitation coil 8 and the second excitation coil 9 can be the same or opposite. Here, excitation direction refers to the direction of the magnetic field. If the current directions of the first excitation coil 8 and the second excitation coil 9 are the same, their excitation directions can be considered the same; if the current directions of the first excitation coil 8 and the second excitation coil 9 are opposite, their excitation directions can be considered opposite. The excitation directions of the first excitation coil 8 and the second excitation coil 9 can be designed according to actual needs, and this application does not impose any restrictions on this.

[0035] 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.

[0036] Based on the above description, it can be seen that the discharge current amplitude may oscillate significantly (i.e., low-frequency oscillation) in the frequency range of 10~100 kHz, which poses a risk of damage to the circuit components of the Hall thruster 100. Therefore, it is necessary to suppress the low-frequency oscillation of the Hall thruster 100. Specifically, the low-frequency oscillation of the Hall thruster 100 is mainly caused by the ionization and replenishment process of the gas in the ionization region, following the expressions (1) and (2) below.

[0037]

[0038]

[0039] in, For ion velocity, For neutral particle velocities, Ion density, For neutral particle density, It is the ionization rate (related to ionization cross section and electron velocity). is the length of the ionization region.

[0040] After combining the above expressions (1) and (2), we get expression (3).

[0041]

[0042] It can be seen that expression (3) is the formula for a second-order harmonic oscillator, where, It can be viewed as the formula for a second-order harmonic oscillator. , This represents the average ion density in the ionization region when the Hall thruster 100 does not experience low-frequency oscillations. This represents the average neutral particle density in the ionization region when the Hall thruster 100 does not experience low-frequency oscillations.

[0043] Based on expression (3), the low-frequency oscillation frequency of the Hall thruster 100 It can be as shown in expression (4).

[0044]

[0045] Based on expression (4), it can be seen that the frequency and amplitude of the low-frequency oscillation of the Hall thruster 100 are related to the ionization rate. Related. Among them, ionization rate For example, as shown in expression (5).

[0046]

[0047] in, For ionization cross section, The electron velocity is the value of the electron. Therefore, controlling the electron behavior in the Hall thruster 100, such as controlling the electron velocity, can effectively suppress low-frequency oscillations in the Hall thruster 100. Furthermore, the electron behavior in the Hall thruster 100 can be controlled by the magnetic field distribution in the discharge region 15.

[0048] Based on the above description, when the oscillation amplitude of the discharge current 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 is lower than the target amplitude (i.e., suppressing low-frequency oscillations of the discharge current). Specifically, the second magnetic field can also be distributed at least in the discharge region 15. The interaction between the first and second magnetic fields in the discharge region 15 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 low-frequency oscillations of the Hall thruster 100.

[0049] In this embodiment, the excitation coils 8 and 9 and the control coil 10 are deployed in a non-series manner, and the excitation power supplies for the excitation coils 8 and 9 and the control coil 10 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 second power supply. This allows for separate 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 example, 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 the current direction 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.

[0050] In summary, in some embodiments of this application, a first excitation coil 8 and a second excitation coil 9 are provided in the Hall thruster 100, and the first magnetic field generated by the first excitation coil 8 and the second excitation coil 9 can be distributed at least in the discharge region 15. This ensures that the ionization process of the Hall thruster 100 proceeds normally, enabling the Hall thruster 100 to generate thrust. Simultaneously, a control coil 10 is provided in the Hall thruster 100. When the Hall thruster 100 experiences low-frequency oscillations, the control coil 10 generates a second magnetic field, adjusting the magnetic field distribution in the discharge region 15. This, in turn, adjusts the electron behavior in the Hall thruster 100, effectively suppressing the low-frequency oscillations of the Hall thruster 100.

[0051] Compared to active and passive control methods used in some technologies to suppress low-frequency oscillations, the method of this application can adjust the magnetic field distribution in the discharge region 15 according to actual needs, which has higher adjustment flexibility and less impact on the operating state of the Hall thruster.

[0052] 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 1 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.

[0053] 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.

[0054] Furthermore, the excitation power sources for the first and second control coils are different. This allows for independent control of the second magnetic fields generated by the first and second control coils, thereby improving adjustment flexibility.

[0055] 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 1 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.

[0056] 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 3 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.

[0057] In practical implementation, the target excitation coil and the target control coil can be deployed using one of the above deployment methods as needed, and this application does not impose any restrictions on this.

[0058] Correspondingly, this application also provides a method for controlling the aforementioned Hall thruster 100 or Hall thruster 200. (See also...) Figure 4 The above is a flowchart illustrating the control method provided in some embodiments of this application. Figure 4In this context, the control methods include the following steps:

[0059] Step S401: Obtain the average value of the first discharge current and the peak-to-peak value of the first discharge current of the Hall thruster.

[0060] 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.

[0061] Step S402: 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.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] Step S403: 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 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.

[0066] 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.

[0067] 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.

[0068] In some embodiments, after energizing the control coil according to the second current reference value, the method of this application may further include:

[0069] 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.

[0070] 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.

[0071] 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.

[0072] 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.

[0073] 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.

[0074] 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 low-frequency oscillation of the Hall thruster has been effectively suppressed, so the excitation voltage of the control coil can be stopped.

[0075] 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 low-frequency oscillation of the Hall thruster. In this case, the current direction of the control coil can be changed.

[0076] See also Figures 5 to 7 . Figure 5 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 6 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 7 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 5 to 7 It can be seen that the magnetic field distribution in the discharge region is gradually changing.

[0077] See also Figures 8 to 10 . Figure 8 for Figure 5 A schematic diagram of the discharge current of the Hall thruster in the diagram. Figure 9 for Figure 6 A schematic diagram of the discharge current of the Hall thruster in the diagram. Figure 10 for Figure 7 A schematic diagram of the discharge current of the Hall thruster in the image. Figures 8 to 10 It can be seen that, after multiple adjustments, the low-frequency oscillation of the Hall thruster has been effectively suppressed.

[0078] The Hall thruster and its control 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 effect accelerator includes an anode, a first excitation coil, a second excitation coil, a discharge channel, and a control coil. The first and second excitation coils generate a first magnetic field, which is distributed at least within a discharge region enclosed by the discharge channel. 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. When the oscillation amplitude of the discharge current is not lower than a target amplitude, the control coil generates a second magnetic field to adjust the magnetic field distribution in the discharge region so that the oscillation amplitude of the discharge current is lower than the target amplitude. The excitation coil and the control coil are deployed in a non-series configuration, and their excitation power supplies are different.

2. The Hall thruster according to claim 1, characterized in that, One of the first excitation coil and the second excitation coil is coaxial with the control coil.

3. The Hall thruster according to claim 1, characterized in that, The control coil includes a first control coil and a second control coil, wherein the first excitation coil is coaxial with the first control coil, and the second excitation coil is coaxial with the second control coil.

4. The Hall thruster according to claim 2 or 3, characterized in that, For the coaxial target excitation coil and target control coil, the deployment method between the target excitation coil and the target control coil is one of the following: The target control coil is located radially outside the target excitation coil, and the radius of the target control coil is larger than the radius of the target excitation coil; The target excitation coil is located radially outside the target control coil, and the radius of the target excitation coil is larger than the radius of the target control coil; Along the axial direction of the target excitation coil and the target control coil, the target control coil is located on one side of the target excitation coil.

5. The Hall thruster according to claim 2 or 3, characterized in that, The Hall thruster further includes a first magnetic pole, a second magnetic pole, a magnetically conductive base plate, a first magnetic screen, and a second magnetic screen. The first magnetic field generated by the first excitation coil and the second excitation coil is guided by the first magnetic pole, the second magnetic pole, the discharge channel, the first magnetic screen, the second magnetic screen, and the magnetically conductive base plate, and is at least distributed in the discharge area enclosed by the discharge channel.

6. A method for controlling the Hall thruster according to any one of claims 1 to 5, characterized in that, The method 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 control coil of the Hall thruster is excited 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.

7. The method according to claim 6, 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.

8. The method according to claim 6, characterized in that, 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 shall be further 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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