Hybrid excitation superconducting monopole generator scheme

Abstract

The invention belongs to the technical field of superconducting motors, and relates to a hybrid excitation superconducting monopole generator scheme which integrally comprises a motor shell 1, a stator module 2, a rotor module 3, a superconducting excitation magnet 4, a motor end cover 5, a left ironed shell 11, a right ironed shell 12, a left spiral cooling water channel 13, a right spiral cooling water channel 14, a liquid inlet 131, a liquid outlet 141, a communicating pipe 15 and a left stator iron core 21. The motor comprises a right side stator iron core 22, an armature winding 23, a stator side magnetic compensation module 24, a rigid rotor 31, a left axial excitation permanent magnet 32, a right axial excitation permanent magnet 33 and a radial excitation permanent magnet 34. A hybrid excitation technology which takes superconducting electrical excitation as a main part and permanent magnet excitation as an auxiliary part is used, so that the space utilization rate of the middle section of the superconducting monopole motor is improved, and magnetic leakage of a rotor pole head and a stator middle section is inhibited; the bearing structure of the motor shell and the superconducting excitation magnet is optimized, the axial length is shortened, the compactness of the whole machine is enhanced, the output power and the power density of the superconducting monopole generator are improved, and the requirements of aviation electric propulsion for high power and light weight of an airborne generator are met.

Description

Technical Field This invention belongs to the field of superconducting motor technology, and more specifically, relates to a hybrid excitation superconducting monopole generator scheme. Background Technology

[0001] In the aviation field, the US N+3 plan, the EU Flightpath 2050, and the World Air Transport Action Group's Waypoint 2050 all clearly state that aircraft electrification is an inevitable trend for future development, and point out that turbine-electric distributed propulsion systems are an important development goal for achieving aviation electrification, while high power density and high efficiency motor technology are one of the biggest challenges for this type of propulsion system.

[0002] Traditional electric motors typically have a power density ranging from 0.5 kW / kg to 2.5 kW / kg, which cannot meet the stringent quality requirements of high-power motors in the aerospace electric propulsion field. Therefore, it is necessary to consider using new technologies to improve the power density of traditional motors. Superconducting materials, with their advantages of carrying large currents and lossless DC operation, are ideal materials for motor windings. When high-temperature superconducting tapes are used as motor windings, the air gap magnetic flux density can be significantly increased to enhance magnetic load, reduce losses to improve motor efficiency, and simultaneously significantly reduce the amount of ferromagnetic materials used, thereby effectively reducing weight and increasing power density.

[0003] Currently, conventional superconducting motors are mainly based on a radial flux-excited salient-pole synchronous motor topology, using superconducting excitation magnets instead of copper excitation coils. The superconducting excitation winding rotates with the rotor, leading to problems such as high-current slip ring brush wear, heat leakage from the superconducting binary leads, dynamic sealing of the shaft cooling channel, and heat leakage through torque transmission, severely limiting the operating speed of this type of superconducting motor. However, a special type of superconducting motor is based on an axial flux-excited single-pole motor topology. By placing the superconducting excitation magnet and a solid rigid rotor on the stator side, it can operate at high speeds of tens of thousands of revolutions per second, meeting the high-speed requirements of airborne generators.

[0004] However, due to the existence of an axial magnetization path and limitations imposed by the properties of magnetic materials, this type of superconducting monopole motor is prone to core saturation and suffers from severe magnetic leakage between the stator and rotor, which significantly impacts the output power and efficiency of the superconducting monopole motor. Furthermore, the superconducting excitation magnet of the monopole motor is located in the middle section of the stator and rotor, preventing effective electromagnetic reactions for electromechanical energy conversion in the middle section, thus wasting space in the middle section of the monopole motor.

[0005] Therefore, this invention patent addresses the problems faced by traditional superconducting monopole motors by proposing a hybrid excitation superconducting monopole generator solution. It uses a "three-in-one" hybrid excitation technology to fully utilize the space in the middle section of the superconducting monopole motor for effective electromagnetic reaction, suppresses leakage flux between the rotor pole head and the middle section of the stator, and significantly improves the output power and power density of this type of superconducting motor, meeting the high speed, high power, and lightweight requirements of airborne generators for aviation electric propulsion. Summary of the Invention

[0006] To address the issues of severe magnetic leakage, rotor magnetic saturation, and ineffective space in the intermediate section of superconducting monopole motors, this invention provides a hybrid excitation superconducting monopole generator solution. Based on the "three-in-one" hybrid excitation technology, the stator and rotor topology and magnetic flux path of the motor are optimized, which suppresses magnetic leakage, improves the space utilization of the motor, and increases the output power level and power density of the motor.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] A high-power-density fully superconducting hybrid excitation generator scheme for aircraft electric propulsion is characterized by comprising a motor housing 1, a stator module 2, a rotor module 3, a superconducting excitation magnet 4, a motor end cover 5, a left iron-clad housing 11, a right iron-clad housing 12, a left spiral cooling water channel 13, a right spiral cooling water channel 14, a liquid inlet 131, a liquid outlet 141, a connecting pipe 15, a left stator core 21, a right stator core 22, an armature winding 23, a stator-side magnetizing module 24, a rigid rotor 31, a left axial excitation permanent magnet 32, a right axial excitation permanent magnet 33, and a radial excitation permanent magnet 34; wherein the rotor module 3 is located at the generator shaft center and provides driving force as a rotating component; the motor housing 1, the stator module 2, and the superconducting excitation magnet 4 are all stationary components and do not move or rotate during the operation of the hybrid excitation superconducting generator.

[0009] Preferably, the motor housing 1 is made of a metal material with excellent magnetic permeability and high strength. According to the characteristics of the axial and radial magnetic flux path of the hybrid excitation superconducting generator, the middle section of the motor housing 1 is locally thickened, and the effective working parts at both ends are thinned to reduce the weight as much as possible while ensuring a smooth magnetic flux path.

[0010] Preferably, the left spiral cooling water channel 13 and the right spiral cooling water channel 14 inside the motor housing 1 play a cooling role for the stator module 2. When the hybrid excitation superconducting generator is running, circulating coolant is introduced to fully cool the generator stator module 2, preventing the generator temperature from rising too high due to excessive heat generated by the stator core.

[0011] Preferably, the left stator core 21 and the right stator core 22 are both formed by stacking high-saturation magnetic material iron-cobalt alloy sheets, and the effective length is the axial length of the pole head section of the rigid rotor 31, which conducts the magnetic flux path between the rigid rotor 31 and the motor housing 1.

[0012] Preferably, the stator-side magnetizing module 24 is composed of an array of ferrite permanent magnets, with the N poles of the permanent magnets horizontally facing the left stator core 21 to block axial leakage of magnetic flux from the left stator core 21 to the right stator core 22. Since the leakage flux in the middle section of the stator side is around 200mT, using low-remanence ferrite permanent magnets is sufficient to effectively block leakage flux without causing severe magnetic saturation of the left stator core 21 due to the residual magnetism of the permanent magnets themselves. The number of ferrite permanent magnets in the stator-side magnetizing module 24 is the same as the number of magnetic teeth in the left stator core 21.

[0013] Preferably, the armature winding 23 is made of copper Litz wire wound into a short-pitch distributed armature winding. Litz wire can effectively reduce copper loss due to its cross-transposition characteristics. The distributed armature winding can effectively reduce harmonics and improve efficiency and slot fill factor.

[0014] Preferably, the superconducting excitation magnet 4 has a hollow structure consisting of a stainless steel cavity and a cooling coil. The cooling coil is in direct contact with the superconducting coil and is filled with a cryogenic coolant. Through conductive cooling, the temperature of the superconducting material is reduced to below the liquid nitrogen temperature range, which can effectively improve the cooling stability and reliability. At the same time, it provides support for the superconducting coil. By evacuating the stainless steel cavity, the radiative heat leakage from the external environment to the inside of the magnet can be effectively reduced, providing a stable low-temperature environment for the superconducting coil.

[0015] Specifically, the superconducting excitation magnet 4 is axially fixed by the left stator core 21 and the right stator core 22. The gap width between the left stator core 21 and the right stator core 22 is smaller than the axial width of the superconducting excitation magnet 4, effectively reducing the space in the middle section and making the overall structure of the motor more compact. However, it is larger than the axial width of the superconducting coil to prevent the strong magnetic field generated by the superconducting coil from causing saturation on the stator core.

[0016] Preferably, the rotor module 3 consists of four parts: a rigid rotor 31, a left-axis excitation permanent magnet 32, a right-axis excitation permanent magnet 33, and a radial excitation permanent magnet 34.

[0017] Specifically, the rigid rotor 31 is integrally forged from a high-saturation magnetic material iron-cobalt alloy, which is robust and reliable and suitable for operation at high speeds above 10,000 rpm. Based on the characteristics of the magnetic flux path of the hybrid excitation superconducting motor, the low magnetic density parts are punched to reduce weight, and the rotor pole edge is geometrically optimized.

[0018] Specifically, the radial excitation permanent magnet 34 is attached to the middle section of the rigid rotor 31 to provide radial excitation magnetomotive force. A portion of the magnetic flux directly and perpendicularly reacts with the armature winding 23, while a portion of the magnetic flux, together with the magnetic flux of the adjacent co-excited salient pole head, forms the total magnetic flux in the magnetic circuit. After being magnetized by the stator core, it reacts with the armature winding 23.

[0019] Specifically, the left-axis excitation permanent magnet 32 ​​and the right-axis excitation permanent magnet 33 are attached to the concave pole of the pole head of the rigid rotor 31. The left-axis excitation permanent magnet 32 ​​is the N pole and the right-axis excitation permanent magnet 33 is the S pole. This compensates for the serious magnetic leakage problem caused by the same polarity on the same side of the rigid rotor 31 and provides axial auxiliary excitation magnetomotive force.

[0020] The hybrid excitation principle of the hybrid excitation superconducting generator of this invention is as follows:

[0021] The "three-in-one" hybrid excitation system consists of three parts: rotor pole head concave pole permanent magnet auxiliary excitation, rotor middle section permanent magnet auxiliary excitation, and stator middle section permanent magnet supplementary excitation.

[0022] Firstly, the equivalent air gap magnetic flux density of a superconducting monopole generator is closely related to the maximum axial magnetic flux of the rotor. For electrically excited and axially permanent magnet excited types, the equivalent air gap magnetic flux density is proportional to the magnitude of the rotor axial magnetic flux, but the directions of the axial magnetic flux are opposite. Therefore, after the magnetic flux of a hybrid-excited superconducting monopole generator is linearly superimposed, the rotor axial magnetic flux does not reach saturation. Further increasing the excitation current allows the equivalent air gap magnetic flux density to continue increasing.

[0023] Secondly, radial excitation permanent magnets with alternating N and S poles are arranged in the middle section of the rotor. Part of the magnetic flux directly and perpendicularly reacts with the armature winding, and part of the magnetic flux together with the magnetic flux of the adjacent salient pole head of the same excitation direction forms the total magnetic flux in the magnetic circuit, which increases the excitation magnetomotive force.

[0024] In order to make the overall structure of the motor more compact, the width of the middle section was reduced, which increased the axial leakage flux of the middle section. Therefore, a circumferential array of permanent magnets was arranged in the middle section of the stator to compensate for the leakage flux. The magnetization direction of the permanent magnets is opposite to the axial leakage flux direction, so as to block the axial magnetic flux leakage on the stator side.

[0025] In summary, the beneficial effects of the hybrid excitation superconducting monopole generator scheme for aircraft electric propulsion formed by the present invention are as follows:

[0026] (1) The present invention provides a hybrid excitation superconducting single-pole generator scheme, which adopts a hybrid excitation structure with "three-in-one" permanent magnet auxiliary excitation. The axial magnetic flux hybrid excitation structure greatly alleviates the problems of rotor easy magnetic saturation and serious pole head magnetic leakage. The radial magnetic flux hybrid excitation structure makes full use of the ineffective space in the middle section of the superconducting single-pole generator, enhances the excitation magnetomotive force, and the stator side magnetic supplementation module blocks the axial magnetic flux leakage between the two stator iron cores, thereby improving the overall structural compactness and power density of the generator.

[0027] (2) The present invention provides a hybrid excitation superconducting monopole generator scheme. The innovative concept proposed is not only applicable to superconducting monopole generators, but can also be used for other types of superconducting generators. The overall concept of the scheme is novel and greatly improves the motor output power and power density. Attached Figure Description

[0028] To more clearly illustrate the technical methods of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is an overall structural diagram of an embodiment of the present invention.

[0030] 1-Motor housing, 4-Superconducting excitation magnet, 5-Motor end cover.

[0031] Figure 2 This is an axial cross-sectional view of an embodiment of the present invention.

[0032] 13-Left spiral cooling water channel, 14-Right spiral cooling water channel, 21-Left stator core, 22-Right stator core, 23-Armature winding, 24-Stator side magnetizing module, 31-Rigid rotor, 32-Left axial excitation permanent magnet, 33-Right axial excitation permanent magnet, 34-Radial excitation permanent magnet.

[0033] Figure 3 This is an exploded view of an embodiment of the present invention.

[0034] 11-Left iron casing, 12-Right iron casing, 21-Left stator core, 22-Right stator core, 23-Armature winding, 24-Stator side magnetizing module, 31-Rigid rotor, 32-Left axial excitation permanent magnet, 33-Right axial excitation permanent magnet, 34-Radial excitation permanent magnet.

[0035] Figure 4 This is a schematic diagram of the three-dimensional magnetic flux path according to an embodiment of the present invention.

[0036] Figure 5 This is a structural diagram of the stator-side magnetizing module according to an embodiment of the present invention.

[0037] Figure 6 This is a structural diagram of the rotor module according to an embodiment of the present invention.

[0038] 31- Rigid rotor, 32- Left axial excitation permanent magnet, 33- Right axial excitation permanent magnet, 34- Radial excitation permanent magnet.

[0039] Figure 7 This is a structural diagram of the axially excitation permanent magnet according to an embodiment of the present invention.

[0040] 32 - Left-axis excitation permanent magnet, 33 - Right-axis excitation permanent magnet.

[0041] Figure 8 This is a structural diagram of the radially excitation permanent magnet according to an embodiment of the present invention.

[0042] Figure 9 This is a structural diagram of the motor housing according to an embodiment of the present invention. Detailed Implementation

[0043] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0044] Figure 1 , Figure 2 and Figure 3These are, respectively, an overall structural diagram, an axial cross-sectional diagram, and an exploded view of a hybrid-excitation superconducting monopole generator scheme for aircraft electric propulsion provided by an embodiment of the present invention. The overall structure includes: a motor housing 1, a stator module 2, a rotor module 3, a superconducting excitation magnet 4, a motor end cover 5, a left iron-clad housing 11, a right iron-clad housing 12, a left spiral cooling water channel 13, a right spiral cooling water channel 14, a connecting pipe 15, a left stator core 21, a right stator core 22, an armature winding 23, a stator-side magnetizing module 24, a rigid rotor 31, a left axial excitation permanent magnet 32, a right axial excitation permanent magnet 33, and a radial excitation permanent magnet 34. First, the left stator core 21 is placed in the left backing housing 11 with an interference fit, and the superconducting excitation magnet 4 is placed in the groove in the left backing housing 11. The connecting pipe 15 is connected to the outlet of the left spiral cooling water channel 13. The stator side magnetizing module 24 is attached and fixed to the magnetic teeth of the left stator core 21. The right stator core 22 is placed in the right backing housing 12 with an interference fit, and the left backing housing 11 and the right backing housing 12 are axially fastened with bolts. The armature winding 24 is wound in the stator core to form a complete stator module 2. The left axial excitation permanent magnet 32, the right axial excitation permanent magnet 33 and the radial excitation permanent magnet 34 are respectively attached to the left pole concave pole, the right pole concave pole and the middle section of the rigid rotor 31, and wrapped with carbon fiber to form a complete rotor module 3. Finally, the rotor module 3 is placed at the axis of the stator module 2, thus forming a complete hybrid excitation superconducting single-pole generator.

[0045] Figure 4 This is a schematic diagram of the magnetic flux path of a hybrid-excitation superconducting monopole generator scheme provided in an embodiment of the present invention. The working principle of this high-power-density fully superconducting hybrid-excitation generator is as follows: When a direct current is passed through the superconducting excitation magnet 4, the induced magnetic field in space will flow along the area with lower magnetic reluctance, and the main magnetic circuit is as follows: Figure 4 The white arrow in the middle indicates: Rotor middle section → Rotor right salient pole → Right air gap → Right stator core 22 → Right iron-coated housing 12 → Left iron-coated housing 11 → Left stator core 21 → Left air gap → Rotor left salient pole → Rotor middle section; Axial excitation auxiliary magnetic circuit as follows Figure 4 The black arrow in the middle indicates: Left axial excitation permanent magnet 32 ​​→ Left air gap → Left stator core 21 → Left iron-coated shell 11 → Right iron-coated shell 12 → Right stator core 22 → Right air gap → Right axial excitation permanent magnet 32 ​​→ Rotor middle section; Radial excitation auxiliary magnetic circuit as follows Figure 4 The solid black arrow in the middle indicates: Radial excitation permanent magnet 34 → right stator core 22 or left stator core 21 → radial excitation permanent magnet 34; the stator-side magnetic compensation circuit is as follows: Figure 4The black dashed arrow in the middle indicates: stator-side magnetizing module 24 → left stator core 21. When the rotor of the onboard high power density hybrid excitation superconducting generator rotates under the action of external force, a rotating magnetic field will be generated in the air gap of the generator. The effective straight segment of the armature winding makes a perpendicular cutting motion relative to the rotating magnetic field, thereby generating an induced electromotive force on the superconducting armature winding, which is connected to the load to transmit electrical energy.

[0046] Figure 5 This is a structural diagram of the stator-side magnetizing module of a hybrid excitation superconducting unipolar generator scheme provided in an embodiment of the present invention. The stator-side magnetizing module 24 is completely fitted with the magnetic teeth of the stator core in the axial direction. The number of permanent magnet blocks contained in the stator-side magnetizing module 24 is the same as the number of magnetic teeth of the stator core, and the size of a single permanent magnet block is exactly the same as that of a single magnetic tooth of the stator core. The magnetization direction of the stator-side magnetizing module 24 is opposite to the axial leakage direction of the main magnetic circuit, thereby blocking magnetic flux leakage in the axial direction of the main magnetic circuit.

[0047] Figure 6 This is a rotor module structure diagram of a hybrid excitation superconducting single-pole generator scheme provided in an embodiment of the present invention. It includes: a rigid rotor 31, a left-axis excitation permanent magnet 32, a right-axis excitation permanent magnet 33, and a radial excitation permanent magnet 34. The left-axis excitation permanent magnet 32 ​​is attached to the concave pole of the left end of the rigid rotor 31, the right-axis excitation permanent magnet 33 is attached to the concave pole of the right end of the rigid rotor 31, and the radial excitation permanent magnet 34 is attached to the middle section of the rigid rotor 31. The rotor module is tightly wrapped with high-strength carbon fiber material using an interference fit to enhance the structural strength and stability of the rotor module 3. Furthermore, based on the magnetic flux path in the rotor module 3, the rigid rotor 31 is structurally optimized by slotting and perforating, reducing the weight of the solid, one-piece cast rigid rotor 31 and increasing the overall power density of the generator.

[0048] Figure 7 This is a structural diagram of the axial excitation permanent magnet in a hybrid excitation superconducting single-pole generator scheme provided by an embodiment of the present invention. The left axial excitation permanent magnet 32 ​​and the right axial excitation permanent magnet 33 are spatially offset by a certain angle, which is 360° / the total number of poles on one side of the rotor module 3. The number of axial excitation permanent magnets is consistent with the number of salient poles on the pole head of the rigid rotor 31. The magnetization direction of the salient poles on the same side of the rotor module 3 is opposite to the magnetization direction of the adjacent axial excitation permanent magnets. Figure 4 As can be seen, in this case, the left-hand axial excitation permanent magnet 32 ​​is the N pole, and the right-hand axial excitation permanent magnet 33 is the S pole. The shape of the axial excitation permanent magnet is not limited to the fan shape proposed in this case, but can also be tile-shaped, lens-shaped, or other shapes that can be adapted to the concave pole of the rigid rotor 31.

[0049] Figure 8This is a structural diagram of the radial excitation permanent magnet in a hybrid excitation superconducting single-pole generator scheme provided by an embodiment of the present invention. The radial excitation permanent magnet 34 is surface-mounted on the middle section of the rigid rotor 31, providing radial excitation magnetomotive force to the stator core. The radial excitation permanent magnet 34 is a tile-shaped permanent magnet, and its number is consistent with the total number of poles on one side of the rotor module 3. The N poles and S poles of the radial excitation permanent magnet 34 are arranged alternately in the circumferential direction, and the polarity of each radial excitation permanent magnet 34 is consistent with the polarity of the adjacent salient pole, which can enhance the total magnetomotive force in the electrical excitation circuit.

[0050] Figure 9 This is a structural diagram of the motor housing of a hybrid excitation superconducting unipolar generator according to an embodiment of the present invention. It includes: a left backing housing 11, a right backing housing 12, a left spiral cooling water channel 13, a right spiral cooling water channel 14, a liquid inlet 131, a liquid outlet 141, and a connecting pipe 15. The left backing housing 11 and the right backing housing 12 are axially fastened together with bolts, serving to conduct the axial magnetic circuit and fix the superconducting excitation magnet 4. Furthermore, the inner edge of the backing housing has a certain degree of structural misalignment with the superconducting excitation magnet 4, shortening the overall axial length of the generator and enhancing the compactness of the overall structure without affecting magnetic circuit flow and magnetic saturation. The left spiral cooling water channel 13 and the right spiral cooling water channel 14 are integrally connected by the connecting pipe 15, providing integrated cooling and heat dissipation for the two stator cores, simplifying the cooling structure components and supporting cooling devices, and enhancing the compactness of the overall cooling structure.

[0051] Of course, the above embodiments are only used to clearly illustrate the technology and features of the present invention so that those skilled in the art can easily understand and implement it, and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made without departing from the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. This invention is a hybrid excitation superconducting single-pole generator scheme, characterized in that, The system includes a motor housing 1, a stator module 2, a rotor module 3, a superconducting excitation magnet 4, and a motor end cover 5. The motor housing 1 comprises a left-end shell 11, a right-end shell 12, a left spiral cooling water channel 13, a right spiral cooling water channel 14, a liquid inlet 131, a liquid outlet 141, and a connecting pipe 15, which provides sufficient cooling for the stator module 2. The stator module 2 includes a left stator core 21, a right stator core 22, an armature winding 23, and a stator-side magnetizing module 24. The rotor module 3 consists of a rigid rotor 31, a left-axial permanent magnet excitation array 32, a right-axial permanent magnet excitation array 33, and a radial permanent magnet excitation array 34.

2. The hybrid excitation superconducting monopole generator scheme as described in claim 1, characterized in that, The hybrid excitation structure with "three-in-one" permanent magnet auxiliary excitation greatly alleviates the problems of rotor magnetic saturation and severe pole head magnetic leakage. The radial magnetic flux hybrid excitation structure makes full use of the ineffective space in the middle section of the superconducting single-pole generator, enhances the excitation magnetomotive force, and the stator-side magnetic compensation module blocks the axial magnetic flux leakage between the two stator cores, thus improving the overall structural compactness and power density of the generator.

3. The hybrid excitation superconducting monopole generator scheme as described in claim 1, characterized in that, The stator-side magnetization module 24 is composed of an array of ferrite permanent magnets. The magnetization direction of the permanent magnets is completely opposite to the axial leakage magnetic direction between the stators. The number of ferrite permanent magnets contained therein is the same as the number of magnetic teeth of the left stator core 21. The permanent magnet array is placed between the left stator core 21 and the right stator core 22, and each permanent magnet is completely aligned with the stator teeth.

4. The hybrid excitation superconducting monopole generator scheme as described in claim 1, characterized in that, The radial permanent magnet excitation array 34 is attached to the middle section of the rigid rotor 31, with the N pole and S pole alternating. The N pole permanent magnet is aligned with the N pole salient pole head, and the S pole permanent magnet is aligned with the S pole salient pole head.

5. The hybrid excitation superconducting monopole generator scheme as described in claim 1, characterized in that, The axial permanent magnet excitation array 32 is attached to the concave pole on the N pole head side of the rigid rotor 31, and the axial permanent magnet excitation array 33 is attached to the concave pole on the S pole head side of the rigid rotor 31.

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