Hall thruster with a plurality of permanent magnet column magnetic circuit structures

Abstract

The application discloses a Hall thruster with a multi-permanent-magnetic-column magnetic circuit structure and belongs to the field of Hall thrusters. The application discloses a Hall thruster with a multi-permanent-magnetic-column magnetic circuit structure and belongs to the field of Hall thrusters. The application discloses a Hall thruster with a multi-permanent-magnetic-column magnetic circuit structure and belongs to the field of Hall thrusters. The application discloses a Hall thruster with a multi-permanent-magnetic-column magnetic circuit structure and belongs to the field of Hall thrusters. The application discloses a Hall thruster with a multi-permanent-magnetic-column magnetic circuit structure and belongs to the field of Hall thrusters. The application discloses a Hall thruster with a multi-permanent-magnetic-column magnetic circuit structure and belongs to the field of Hall thrusters.

Description

Technical Field

[0001] This invention relates to the permanent magnet pole structure of Hall thrusters, and belongs to the field of Hall thrusters. Background Technology

[0002] A Hall thruster is an electric thruster that uses orthogonal electromagnetic fields to ionize and accelerate atomic working fluid, converting electrical energy into ion kinetic energy to achieve a high specific impulse. It features simple structure, high specific impulse, high efficiency, long service life, high power density, and long on-orbit service time. It is suitable for various spacecraft missions including attitude control, orbit correction, orbit transfer, dynamic compensation, position holding, repositioning, deorbiting, space exploration, and interplanetary travel. It is currently the most widely used and mature electric propulsion system internationally.

[0003] There are two main excitation methods for Hall thrusters: coil excitation and permanent magnet excitation. Generally speaking, coil excitation requires more energy consumption, and the excitation current also generates heat, placing higher demands on the heat dissipation structure of the Hall thruster. Therefore, it is more suitable for high-power Hall thrusters. For low-power Hall thrusters, due to their compact structure and limited space, setting up excitation coils presents significant challenges in terms of magnetic field density and heat dissipation. Therefore, permanent magnets are preferred as the magnetic field structure. The magnetic circuit structure of a Hall thruster is mainly divided into two parts: the inner magnetic circuit and the outer magnetic circuit. Taking permanent magnet excitation as an example, the inner permanent magnet is mainly a permanent magnet column or a permanent magnet ring with a small inner diameter, while the outer permanent magnet is mainly a permanent magnet ring with a larger radius.

[0004] As the main component of the magnetic circuit of a permanent magnet Hall thruster, the permanent magnet ring is difficult to manufacture, costly, and time-consuming. Replacing it after damage is particularly costly in terms of both economy and time, causing significant inconvenience to the design and maintenance of the thruster. Summary of the Invention

[0005] To address the problems existing in the use of permanent magnet rings as the main magnetic circuit structure of permanent magnet Hall thrusters, this invention provides a Hall thruster with a multi-permanent magnet column magnetic circuit structure.

[0006] The Hall thruster with a multi-permanent magnet column magnetic circuit structure described in this invention includes a base 1, an outer permanent magnet pole 2, a ceramic channel 3, and an inner permanent magnet pole 4. The outer permanent magnet pole 2, the ceramic channel 3, and the inner permanent magnet pole 4 are coaxially arranged from the outside to the inside on the base 1.

[0007] The outer permanent magnet pole 2 includes multiple first permanent magnet pillars 2-1, a first ring upper cover plate 2-2 and a first ring lower cover plate 2-3, with multiple first permanent magnet pillars 2-1 evenly distributed circumferentially between the first ring upper cover plate 2-2 and the first ring lower cover plate 2-3.

[0008] The inner permanent magnet pole 4 includes multiple second permanent magnet pillars 4-1, a second ring upper cover plate 4-2, and a second ring lower cover plate 4-3. Multiple second permanent magnet pillars 4-1 are evenly distributed circumferentially between the second ring upper cover plate 4-2 and the second ring lower cover plate 4-3.

[0009] Preferably, the upper cover plate 2-2 of the first ring, the lower cover plate 2-3 of the first ring, the upper cover plate 4-2 of the second ring, and the lower cover plate 4-3 of the second ring are pure iron rings.

[0010] Preferably, circular grooves are provided on the first ring upper cover plate 2-2, the first ring lower cover plate 2-3, the second ring upper cover plate 4-2, and the second ring lower cover plate 4-3 for positioning and installing the first permanent magnet column 2-1 and the second permanent magnet column 4-1.

[0011] Preferably, the inner diameter and outer diameter of the upper cover plate 4-2 and the lower cover plate 4-3 of the second ring are equal.

[0012] Preferably, the inner diameters and outer diameters of the upper cover plate 2-2 and the lower cover plate 2-3 of the first ring are equal.

[0013] Preferably, the outer permanent magnet pole 2 further includes an extension plate 2-4, the inner diameter of the upper cover plate 2-2 of the first ring and the outer diameter of the lower cover plate 2-3 of the first ring are equal, and the outer edge of the upper cover plate 2-2 of the first ring extends radially to form the extension plate 2-4.

[0014] Preferably, the upper cover plate 2-2 of the first ring and the upper cover plate 4-2 of the second ring are made of pure iron rings with a thickness of 1.2 mm, and the lower cover plate 2-3 of the first ring and the lower cover plate 4-3 of the second ring are made of pure iron rings with a thickness of 1 mm.

[0015] Preferably, the number of permanent magnet columns 2-1 is determined with reference to the equivalent principle of traditional permanent magnet rings. The specific equivalent principle is as follows:

[0016] Principle 1: The mid-diameter of the first permanent magnet column 2-1 and the traditional permanent magnet ring are consistent;

[0017] Principle 2: The excitation area of ​​permanent magnet column 2-1 and traditional permanent magnet ring tends to be consistent;

[0018] Principle 3: The height of permanent magnet column 2-1 and the traditional permanent magnet ring tend to be consistent;

[0019] The equivalence principle of permanent magnet column 4-1 is the same as that of permanent magnet column 2-1.

[0020] The beneficial effects of this invention are as follows: This invention uses a Hall thruster with permanent magnet excitation. In the structure of the inner and outer permanent magnets, a multi-permanent magnet column structure is used to equivalently replace the permanent magnet ring. This can greatly reduce the cost in the actual processing of magnetic circuit components. At the same time, it can achieve the same excitation effect as the permanent magnet ring. In addition, the gaps between the permanent magnet columns can be used to dissipate heat and reduce the temperature of the permanent magnet. It is also easier to replace some permanent magnet columns if damage occurs in later use, which is highly economical. Attached Figure Description

[0021] Figure 1 This is a three-dimensional structural schematic diagram of a Hall thruster with a multi-permanent magnet column magnetic circuit structure as described in this invention;

[0022] Figure 2 This is a schematic diagram of the three-dimensional structure of the inner and outer permanent magnet poles in Implementation Method 1;

[0023] Figure 3 This is a schematic diagram of the three-dimensional structure of the external permanent magnet pole in Implementation Method 2;

[0024] Figure 4 This is a cross-sectional view of the external permanent magnet pole in Implementation Method 1;

[0025] Figure 5 This is a cross-sectional view of the external permanent magnet pole in Implementation Method 2;

[0026] Figure 6 This is a schematic diagram of the magnetic interface of a permanent magnet Hall thruster using the external permanent magnet structure of Embodiment 1;

[0027] Figure 7 This is a schematic diagram of the magnetic interface of a permanent magnet Hall thruster using the external permanent magnet structure of Embodiment 2. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0030] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but this is not intended to limit the scope of the invention.

[0031] Specific Implementation Method 1: The following is combined with... Figure 1 , 2The following describes the embodiment of the Hall thruster with a multi-permanent magnet column magnetic circuit structure, which includes a base 1, an outer permanent magnet pole 2, a ceramic channel 3 and an inner permanent magnet pole 4. The outer permanent magnet pole 2, the ceramic channel 3 and the inner permanent magnet pole 4 are coaxially arranged from the outside to the inside on the base 1.

[0032] The outer permanent magnet pole 2 includes multiple first permanent magnet pillars 2-1, a first ring upper cover plate 2-2 and a first ring lower cover plate 2-3, with multiple first permanent magnet pillars 2-1 evenly distributed circumferentially between the first ring upper cover plate 2-2 and the first ring lower cover plate 2-3.

[0033] The inner permanent magnet pole 4 includes multiple second permanent magnet pillars 4-1, a second ring upper cover plate 4-2, and a second ring lower cover plate 4-3. Multiple second permanent magnet pillars 4-1 are evenly distributed circumferentially between the second ring upper cover plate 4-2 and the second ring lower cover plate 4-3.

[0034] To fully homogenize the circumferential symmetry of the magnetic field generated by the permanent magnet column array, cover plates made of pure iron are added above and below permanent magnet column 2-1 and permanent magnet column 4-1. Specifically, the upper cover plate 2-2, lower cover plate 2-3, upper cover plate 4-2, and lower cover plate 4-3 of the first ring are all made of pure iron. For example, the upper cover plate 2-2 and upper cover plate 4-2 of the first and second rings are made of pure iron rings with a thickness of 1.2 mm. At the contact points with the permanent magnet columns, circular grooves with a depth of 0.4 mm, the same number and diameter as the permanent magnet columns, are cut on the rings for positioning and installing permanent magnet columns 2-1 and 4-1. Simultaneously, the pure iron rings can homogenize the magnetic field generated by the permanent magnet columns, making its circumferential symmetry stronger. The lower cover plate 2-3 of the first ring and the lower cover plate 4-3 of the second ring are made of pure iron rings with a thickness of 1mm. While homogenizing the magnetic field, they can also protect the permanent magnet column from being directly squeezed and damaged by the outer magnetic pole cover plate.

[0035] The overall positioning of the outer permanent magnet pole 2 structure is determined by the thruster base and the outer permanent magnet washer, the diameter of which is consistent with the inner and outer diameters of the lower cover plate 4-3 of the second ring. The inner diameter of the lower cover plate 4-3 of the second ring is consistent with the outer diameter of the washer, and the outer diameter is consistent with the inner diameter of the stepped retaining ring of the thruster base. The washer and the base structure cooperate to position and install the structure.

[0036] In this embodiment, the contact points of the upper cover plate 2-2 of the first ring, the lower cover plate 2-3 of the first ring, and the base 1 are connected by bolts. The outer permanent magnet washer is made of non-magnetic material and does not affect the magnetic field of the outer permanent magnet.

[0037] The inner diameters and outer diameters of the upper cover plate 2-2 and the lower cover plate 2-3 of the first ring are equal. The inner diameters and outer diameters of the upper cover plate 4-2 and the lower cover plate 4-3 of the second ring are equal.

[0038] This embodiment describes a magnetic circuit structure with multiple external permanent magnet pillars. Several permanent magnet pillars are arranged in a ring to form a permanent magnet ring. The magnetic field strength and configuration generated are calculated, and through comparison and adjustment, a magnetic field structure equivalent to the external permanent magnet ring is obtained. A key point is that when the magnetic field is generated by the first permanent magnet pillar 2-1 / second permanent magnet pillar 4-1 described in this embodiment, its radial width and thickness are relatively small. The inner diameter is mainly determined by the dimensions of the channel and the magnetic screen. The height and position should be basically consistent with those of a traditional permanent magnet ring placed at the corresponding position. Simultaneously, to ensure the magnetic field strength and configuration within the channel, the mid-diameter of the arrangement of the first permanent magnet pillar 2-1 / second permanent magnet pillar 4-1 should also be basically consistent with the mid-diameter of the permanent magnet ring, which can be adjusted appropriately. This imposes many restrictions on the size and dimensions of the permanent magnet pillars, and the number of permanent magnet pillars required to generate the same magnetic field strength and the homogenization effect must also be considered. In principle, the number of permanent magnet columns should be as large as possible within a limited space to achieve a uniform circumferential distribution, but a compromise must also be made with their size to ultimately calculate the equivalence between permanent magnet columns and permanent magnet rings.

[0039] The number of permanent magnet columns 2-1 is determined with reference to the equivalent principle of traditional permanent magnet rings. The specific equivalent principle is as follows:

[0040] Principle 1: The mid-diameter of the first permanent magnet column 2-1 and the traditional permanent magnet ring are consistent;

[0041] Principle 2: The excitation area of ​​permanent magnet column 2-1 and traditional permanent magnet ring tends to be consistent;

[0042] Principle 3: The height of permanent magnet column 2-1 and the traditional permanent magnet ring tend to be consistent;

[0043] The equivalence principle of permanent magnet column 4-1 is the same as that of permanent magnet column 2-1.

[0044] Specific Implementation Method Two: The following is combined with... Figure 3 , 5 Sections 6 and 7 describe this embodiment. This embodiment further explains the first embodiment. The outer permanent magnet pole 2 also includes an extension plate 2-4. The inner diameters of the upper cover plate 2-2 of the first ring and the lower cover plate 2-3 of the first ring are equal and the outer diameters are equal. The outer edge of the upper cover plate 2-2 of the first ring extends radially to form the extension plate 2-4.

[0045] Because the width of the outer extension plate 2-4 increases after the addition of the cover plate 2-2 of the first ring, the magnetic field generated by the permanent magnet column 2-1 will expand radially outward. Therefore, the external magnetic interface will also move outward. Figure 7 As shown. Corresponding Figure 6This diagram illustrates the magnetic interface location of the non-extended magnetic pole structure in Embodiment 1. Except for the width of the upper cover plate, all other components are identical. Therefore, it can be seen that the extension of the upper cover plate 2-2 of the first ring in this embodiment serves to adjust the magnetic interface. Since the extension plate 2-4 is thinner than the upper cover plate 2-2 of the first ring, it has less impact on the external magnetic field strength, allowing for a larger installation space for the cathode without significantly altering the external magnetic field.

[0046] This embodiment takes into account the impact of the coupling between the external magnetic interface and the cathode position on the discharge performance of the Hall thruster with permanent magnet structure. The design enlarges the outer diameter of the upper part of the outer magnetic pole so that the external magnetic interface is pushed outward radially, increasing the space inside the magnetic interface, thereby increasing the spatial flexibility of the external cathode arrangement.

[0047] While the invention has been described herein with reference to specific embodiments, it should be understood that these embodiments are merely examples of the principles and applications of the invention. Therefore, it should be understood that many modifications can be made to the exemplary embodiments, and other arrangements can be designed without departing from the spirit and scope of the invention as defined by the appended claims. It should be understood that different dependent claims and features described herein can be combined in ways different from those described in the original claims. It is also understood that features described in conjunction with individual embodiments can be used in other described embodiments.

Claims

1. A Hall thruster with a multi-permanent magnet column magnetic circuit structure, characterized in that, It includes a base (1), an outer permanent magnet pole (2), a ceramic channel (3) and an inner permanent magnet pole (4). The outer permanent magnet pole (2), the ceramic channel (3) and the inner permanent magnet pole (4) are coaxially arranged from the outside to the inside on the base (1). The outer permanent magnet pole (2) includes multiple first permanent magnet pillars (2-1), a first ring upper cover plate (2-2), a first ring lower cover plate (2-3), and an extension plate (2-4). Multiple first permanent magnet pillars (2-1) are evenly distributed circumferentially between the first ring upper cover plate (2-2) and the first ring lower cover plate (2-3). The first ring upper cover plate (2-2) and the first ring lower cover plate (2-3) have equal inner diameters and equal outer diameters. The outer edge of the first ring upper cover plate (2-2) extends radially to form an extension plate (2-4). The inner permanent magnet pole (4) includes multiple second permanent magnet columns (4-1), a second ring upper cover plate (4-2), and a second ring lower cover plate (4-3). Multiple second permanent magnet columns (4-1) are evenly distributed circumferentially between the second ring upper cover plate (4-2) and the second ring lower cover plate (4-3). The second ring upper cover plate (4-2) and the second ring lower cover plate (4-3) have the same inner diameter and the same outer diameter. The upper cover plate (2-2) of the first ring, the lower cover plate (2-3) of the first ring, the upper cover plate (4-2) of the second ring, and the lower cover plate (4-3) of the second ring are all made of pure iron. The number of permanent magnet columns (2-1) is determined with reference to the equivalent principle of traditional permanent magnet rings. The specific equivalent principle is as follows: Principle 1: The center diameter of the first permanent magnet column (2-1) is consistent with that of the traditional permanent magnet ring; Principle 2: The excitation area of ​​the first permanent magnet column (2-1) and the traditional permanent magnet ring tends to be consistent; Principle 3: The height of the first permanent magnet column (2-1) and the traditional permanent magnet ring tend to be consistent; The equivalence principle of permanent magnet column No. 2 (4-1) is the same as that of permanent magnet column No. 1 (2-1).

2. The Hall thruster with a multi-permanent magnet column magnetic circuit structure according to claim 1, characterized in that, The upper cover plate (2-2) of the first ring, the lower cover plate (2-3) of the first ring, the upper cover plate (4-2) of the second ring, and the lower cover plate (4-3) of the second ring have circular grooves for positioning and installing the first permanent magnet column (2-1) and the second permanent magnet column (4-1).

3. The Hall thruster with a multi-permanent magnet column magnetic circuit structure according to claim 1, characterized in that, The upper cover plate of the first ring (2-2) and the upper cover plate of the second ring (4-2) are made of pure iron rings with a thickness of 1.2mm, while the lower cover plate of the first ring (2-3) and the lower cover plate of the second ring (4-3) are made of pure iron rings with a thickness of 1mm.

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