H-shaped bridge type magnetic circuit magnetic flux adjustable inductor motor

Abstract

The invention discloses an H-shaped bridge type magnetic circuit magnetic flux adjustable inductor motor. The inductor motor comprises a rotor, a stator iron core, a magnetic conduction machine shell, a permanent magnet assembly and a direct current magnetic adjusting winding which are coaxially arranged. The permanent magnet assembly is composed of a magnetic bridge, a first permanent magnet ring and a second permanent magnet ring, wherein the first permanent magnet ring and the second permanent magnet ring are symmetrically arranged on the two sides of the magnetic bridge. Each permanent magnet ring is composed of high-coercivity permanent magnet sections and low-coercivity permanent magnet sections which are alternately arranged in the circumferential direction. The magnetization state of the low-coercivity permanent magnet section can be changed by applying pulse current through the direct-current magnetic adjusting winding. In a standby state, the permanent magnets are magnetized reversely, magnetic circuits of the high-coercive-force permanent magnet sections on the same side are short-circuited through a magnetic bridge, air gap magnetic flux is almost zero, and iron loss is eliminated; during working, the magnetic adjusting winding is disconnected, magnetic fluxes of the two permanent magnets are connected in parallel to supply magnetism, the high-coercive-force permanent magnets can stabilize working points of the low-coercive-force permanent magnets, the demagnetization resistance is high, and wide-range and high-reliability magnetic flux adjustment is achieved.

Description

Technical Field

[0001] This invention relates to the field of motor technology, and in particular to an H-type bridge magnetic circuit adjustable flux induction sub-motor. Background Technology

[0002] Induction motors, with their significant advantages of simple structure, high mechanical strength, high reliability, and high power density, occupy an important position in flywheel energy storage systems, uninterruptible power supply systems, and other fields, becoming the core device for energy conversion. Traditional induction motors mainly employ two excitation methods: electrical excitation and permanent magnet excitation. While electrical excitation can eliminate standby losses by cutting off the excitation current, it suffers from significant excitation copper losses during operation, resulting in low motor efficiency. Although permanent magnet excitation avoids excitation copper losses, the non-adjustable permanent magnet magnetic field causes continuous iron losses in the motor even under standby no-load conditions, severely restricting the overall energy efficiency improvement of the system.

[0003] To address the issue of insufficient adjustability of permanent magnet magnetic fields, the industry has developed flux regulation technology that alters the magnetization state of low-coercivity permanent magnets by applying charging and demagnetizing pulse currents to the windings. This has led to three mainstream magnetic circuit structures: parallel, series, and hybrid. However, all three suffer from technical drawbacks, making it difficult to balance magnetic adjustment performance with operational stability. Parallel magnetic circuits offer a wide adjustment range and require less current, but the combined demagnetizing effect of high-coercivity permanent magnets and load current results in extreme instability at the operating point of low-coercivity permanent magnets, making irreversible demagnetization likely. Series magnetic circuits, leveraging the stabilizing properties of high-coercivity permanent magnets, can ensure stable operating points for low-coercivity permanent magnets, but require a large demagnetizing current and have a narrow adjustment range, failing to completely eliminate air gap flux and resulting in limited standby iron loss suppression. Hybrid magnetic circuits attempt to combine the advantages of the former two, but have yet to overcome the technical bottleneck of 100% adjustment range. Residual air gap flux in standby mode prevents complete elimination of iron losses, failing to fundamentally solve the efficiency improvement problem.

[0004] In addition to mechanical adjustment, existing magnetic flux regulation methods include mechanical adjustment and direct-axis current weakening adjustment. Mechanical adjustment requires additional auxiliary equipment such as servo motors, and adjusts the magnetic flux by changing the relative position of the magnetic ring and the permanent magnet. This not only increases system complexity and cost, but is also limited by the response speed of mechanical equipment, making it impossible to achieve rapid online adjustment, resulting in poor reliability and economy. Direct-axis current weakening adjustment adjusts the magnetic flux by changing the current magnitude, but has a narrow adjustment range and generates additional copper losses, making it difficult to achieve efficient and energy-saving operation.

[0005] The patent with publication number CN120150393B discloses a flywheel energy storage flux adjustable induction motor, which uses two permanent magnets with different coercivity and a DC magnetic adjustment winding. The residual magnetism of the low coercivity permanent magnet is adjusted by square wave pulse to achieve air gap flux adjustment. During operation, the magnetic fluxes of the two permanent magnets are connected in parallel to supply magnetism. During standby, the magnetic fluxes cancel each other out by reverse magnetization. Although standby iron loss can be eliminated, the permanent magnets are only arranged at intervals along the circumference and lack a special magnetic circuit topology design. Under the working state, the low coercivity permanent magnet still faces the risk of demagnetization caused by load current, and the stability needs to be further improved.

[0006] In summary, there is an urgent need for a comprehensive solution that can achieve full-coverage adjustment of air gap flux from its rated value to zero, just like a parallel magnetic circuit, to completely eliminate standby iron loss, and can also effectively protect low coercivity permanent magnets from demagnetization by load current, just like a series magnetic circuit, thus ensuring long-term stable operation of the system. Summary of the Invention

[0007] In view of this, the purpose of the present invention is to provide an H-type bridge magnetic circuit flux adjustable induction sub-motor. This magnetic circuit structure not only takes into account the advantages of the series structure in stabilizing the operating point of the low coercivity permanent magnet, but also has the characteristics of the parallel magnetic circuit structure with 100% magnetic adjustment range. Moreover, this magnetic circuit structure can eliminate iron loss in the standby state, while also ensuring the stability of the motor.

[0008] The technical solution adopted by this invention to solve its technical problem is: An H-type bridge-type magnetic circuit flux-adjustable induction motor is provided, comprising a rotor, a stator core, a magnetic housing, a permanent magnet assembly, and a DC magnetic adjustment winding arranged coaxially. The stator core is sleeved on the outside of the rotor, and an armature winding is arranged in its inner ring. The magnetic housing consists of a first magnetic housing and a second magnetic housing correspondingly covering the outside of the first and second stator core segments. The permanent magnet assembly is disposed between the first and second magnetic housing segments and includes an annular magnetic bridge and a first permanent magnet ring and a second permanent magnet ring symmetrically arranged on both sides of the axial direction of the magnetic bridge. The first and second permanent magnet rings are both composed of high-coercivity permanent magnet segments and low-coercivity permanent magnet segments arranged alternately and closely in circumferential direction. The DC magnetic adjustment winding is arranged around the inside of the permanent magnet assembly along the inner circumference of the magnetic bridge.

[0009] Preferably, the initial magnetization direction of the high coercivity permanent magnet segment and the low coercivity permanent magnet segment is axial magnetization, and their curvature, thickness, and length dimensions are completely consistent. In the initial working state, their initial remanence is equal.

[0010] Preferably, the high coercivity permanent magnet segment is made of neodymium iron boron permanent magnet, and the low coercivity permanent magnet segment is made of aluminum nickel cobalt permanent magnet.

[0011] Preferably, the first permanent magnet ring is composed of alternating segments of a first high coercivity permanent magnet and a first low coercivity permanent magnet; the second permanent magnet ring is composed of alternating segments of a second high coercivity permanent magnet and a second low coercivity permanent magnet, and the first low coercivity permanent magnet segment and the corresponding second low coercivity permanent magnet segment are offset from each other by a predetermined mechanical angle in the circumferential direction.

[0012] Preferably, the first permanent magnet ring and the second permanent magnet ring each have no less than 40 segments, and the number of high coercivity permanent magnet segments is equal to the number of low coercivity permanent magnet segments.

[0013] Preferably, the preset mechanical angle between the first low coercivity permanent magnet segment and the corresponding second low coercivity permanent magnet segment is 9 degrees.

[0014] Preferably, the magnetic bridge, together with the first permanent magnet ring and the second permanent magnet ring on both sides, constitutes a plurality of H-shaped bridge magnetic circuit units distributed circumferentially; in each H-shaped bridge magnetic circuit unit, the two permanent magnet segments located on the same axial bridge arm have different coercivity, and the two permanent magnet segments located on the diagonal bridge arms have the same coercivity.

[0015] Preferably, when the DC magnetic winding is not energized, the axial magnetization directions of all permanent magnet segments in the first and second permanent magnet rings are the same. Within the same permanent magnet ring, the magnetic flux generated by adjacent high-coercivity permanent magnet segments and low-coercivity permanent magnet segments is transmitted through the magnetic bridge axis magnetic circuit and then converges on the magnetic housing, and enters the main magnetic circuit composed of the magnetic housing, stator core and air gap in parallel.

[0016] Preferably, when a current is passed through the DC magnetizing winding to cause the low coercivity permanent magnet segment to undergo reverse saturation magnetization, within a single permanent magnet ring, the low coercivity permanent magnet segment with reversed remanence direction short-circuits the magnetic circuits of the two adjacent high coercivity permanent magnet segments in the circumferential direction through the magnetic bridge, so that the magnetic flux generated by the permanent magnet assembly no longer enters the air gap.

[0017] Preferably, the stator core includes a first stator core and a second stator core spaced apart along the rotor axis. The rotor has salient poles at both ends, and the salient pole at one end of the rotor is 180 electrical degrees out of phase with the corresponding salient pole at the other end in the axial direction.

[0018] The beneficial effects of this invention are: This invention provides an H-type bridge-type magnetic circuit flux-adjustable induction motor. Through an innovative H-type bridge-type magnetic circuit structure design, permanent magnets with different coercivities are rationally configured on the bridge arms. This utilizes the magnetic stabilization characteristics of high-coercivity permanent magnets to stabilize the operating point of low-coercivity permanent magnets, effectively resisting the demagnetizing effect of load current and preventing irreversible demagnetization of low-coercivity permanent magnets, significantly improving the reliability and stability of the motor's operating state. Simultaneously, in conjunction with the magnetic adjustment function of the DC magnetic adjustment winding, 100% adjustment of the motor's magnetic flux can be achieved. In standby mode, reverse magnetization short-circuits the high-coercivity permanent magnets with low-coercivity permanent magnets, making the air gap flux nearly zero, completely eliminating standby iron losses and significantly improving system operating efficiency. Compared to traditional mechanical magnetic adjustment methods, this invention requires no additional auxiliary equipment; magnetic flux adjustment can be achieved solely through the adjustable remanence of low-coercivity permanent magnets, simplifying the system structure and reducing costs. In addition, the DC magnetizing winding can also serve as a backup excitation source, further preventing the risk of permanent magnet demagnetization and ensuring the stable and efficient operation of the motor under different operating conditions. It is especially suitable for applications such as flywheel energy storage systems that have high requirements for efficiency and reliability. Attached Figure Description

[0019] Figure 1 This is an exploded schematic diagram of the H-type bridge magnetic circuit flux adjustable inductor memory motor of the present invention; Figure 2 This is a cross-sectional schematic diagram of the H-type bridge magnetic circuit flux adjustable inductor memory motor of the present invention. Figure 3 This is a schematic diagram showing the remanent magnetization direction of the permanent magnet in the working state of the motor proposed in this invention. Figure 4 This is a schematic diagram of the magnetic circuit of the motor in operation according to the present invention; Figure 5 This is a schematic diagram of the magnetic circuit for the motor magnetization process proposed in this invention; Figure 6 This is a schematic diagram of the residual magnet direction and magnetic circuit of the permanent magnet in the standby state of the motor proposed in this invention.

[0020] Figure 7 This is a schematic diagram showing the change of air gap magnetic flux density with rotor mechanical angle before and after magnetic adjustment of the motor proposed in this invention.

[0021] Figure 8 This is a magnetic flux density cloud map of the motor proposed in this invention under different states.

[0022] In the diagram: 1. Rotor; 2. DC magnetic winding; 301. First stator core section; 302. Second stator core section; 401. First magnetic housing section; 402. Second magnetic housing section; 5. Armature winding; 6. First permanent magnet ring; 7. Second permanent magnet ring; 601. First high coercivity permanent magnet section; 602. First low coercivity permanent magnet section; 701. Second high coercivity permanent magnet section; 702. Second low coercivity permanent magnet section; 8. Magnetic bridge.

[0023] It should be noted that these accompanying drawings and textual descriptions are not intended to limit the scope of the invention in any way, but rather to illustrate the concept of the invention to those skilled in the art by referring to specific embodiments. Detailed Implementation

[0024] 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.

[0025] like Figure 1 As shown, an H-type bridge-type magnetic circuit flux-adjustable induction motor includes: a rotor 1, a stator core, a magnetic housing, a permanent magnet assembly, and a DC magnetic adjustment winding 2, all coaxially arranged. The stator core is sleeved on the outside of the rotor 1, and an armature winding 5 is arranged in its inner ring. The magnetic housing consists of a first magnetic housing 401 and a second magnetic housing 402 correspondingly covering the outside of the first stator core 301 and the second stator core 302. The permanent magnet assembly is disposed between the first magnetic housing 401 and the second magnetic housing 402, and includes an annular magnetic bridge 8 and a first permanent magnet ring 6 and a second permanent magnet ring 7 symmetrically arranged on both sides of the axial direction of the magnetic bridge 8. The first permanent magnet ring 6 and the second permanent magnet ring 7 are both composed of high coercivity permanent magnet segments and low coercivity permanent magnet segments arranged alternately and closely in the circumferential direction. The DC magnetic adjustment winding 2 is arranged around the inside of the permanent magnet assembly along the inner circumference of the magnetic bridge 8.

[0026] It should be noted that the rotor 1, as a moving component in the magnetic field, rotates and cuts the air gap magnetic flux provided by the stator side, thereby inducing an electromotive force in the armature winding 5, realizing the core function of electromechanical energy conversion. The stator core, which is sleeved on the outside of the rotor 1, not only provides support and heat dissipation for the armature winding 5, but its high magnetic permeability also constitutes the key path for the magnetic flux to enter the air gap and pass through the rotor 1, making it an indispensable part of the main magnetic circuit. The armature winding 5, which is set in the inner ring of the stator core, serves as the energy exchange port of the motor. After current is applied, it generates an armature reaction magnetic field, which interacts with the permanent magnet magnetic field to generate electromagnetic torque, driving the rotor 1 to rotate or generating electricity. The magnetic conductive housing covering the outside of the stator core, especially the segmented first magnetic conductive housing 401 and the second magnetic conductive housing 402, constitutes the "outer shell" path for the axial flow of magnetic flux, efficiently guiding the magnetomotive force generated by the permanent magnet assembly to the stator core. The permanent magnet assembly between the housings is the excitation source of the entire motor. The annular magnetic bridge 8 acts as a key magnetic circuit "hub" and "short-circuit bridge," providing a dedicated low-resistance channel for the redistribution and closure of magnetic flux in the circumferential direction. The first permanent magnet ring 6 and the second permanent magnet ring 7, symmetrically placed on both sides of the magnetic bridge 8, construct the basic unit of the H-type bridge magnetic circuit by arranging high and low coercivity permanent magnet segments alternately and closely in the circumferential direction. This allows the high coercivity permanent magnet segment to stably provide the basic magnetomotive force, while the magnetization state of the low coercivity permanent magnet segment can be changed externally. Finally, the DC magnetic adjustment winding 2, which is arranged around the inner circumference of the magnetic bridge 8, works by generating an axial magnetic adjustment magnetic field concentrated in the permanent magnet assembly area when a pulse current is applied. This magnetic field can selectively change the magnetization intensity or direction of adjacent low coercivity permanent magnet segments without affecting the high coercivity permanent magnet segments, thereby achieving flexible and rapid adjustment of the air gap synthetic magnetic flux.

[0027] Furthermore, such as Figure 2 As shown, the initial magnetization direction of the high coercivity permanent magnet segment and the low coercivity permanent magnet segment is axial magnetization, and their curvature, thickness and length dimensions are completely consistent. In the initial working state, their initial remanence is equal.

[0028] It should be noted that the high-coercivity permanent magnet section and the low-coercivity permanent magnet section are axially magnetized, which ensures stable axial transmission of magnetic flux and provides a directional excitation foundation for the magnetic circuit. The two sections have identical arc, thickness, and length dimensions, which ensures uniform magnetic flux distribution in the magnetic circuit and avoids uneven magnetic resistance and local magnetic saturation caused by size differences. In the initial working state, the initial residual magnetism of the two sections is equal, which allows the two permanent magnet sections to work together to supply magnetism and form a stable initial excitation magnetic flux. At the same time, it provides the premise for achieving magnetic flux cancellation and short-circuiting of the high-coercivity permanent magnet section by reverse magnetization in the standby state, ensuring the accuracy and thoroughness of magnetic flux adjustment, thereby ensuring the stable operation and high energy efficiency of the motor under different operating conditions.

[0029] Furthermore, the high coercivity permanent magnet segment is made of neodymium iron boron permanent magnet, and the low coercivity permanent magnet segment is made of AlNiCo permanent magnet.

[0030] It should be noted that the high-coercivity permanent magnet section uses neodymium iron boron (NdFeB) material. Utilizing its strong and stable magnetic properties, it can stabilize the operating point of the low-coercivity permanent magnet section during operation, resisting the demagnetizing effect of load current and preventing irreversible demagnetization of the low-coercivity permanent magnet section, thus ensuring the reliability of the magnetic circuit operation. The low-coercivity permanent magnet section uses AlNiCo material. Due to its characteristic that its magnetization state is easily altered by external magnetic fields, the direction and magnitude of residual magnetism can be flexibly adjusted under the influence of the magnetic field generated by the DC magnetic adjustment winding 2. This provides an operable basis for flux adjustment. Combined with the magnetic stabilization effect of the NdFeB permanent magnet section, it achieves a wide range of flux adjustment while ensuring stable motor operation under different operating conditions.

[0031] Furthermore, such as Figure 3 As shown, the first permanent magnet ring 6 is composed of alternating first high coercivity permanent magnet segments 601 and first low coercivity permanent magnet segments 602; the second permanent magnet ring 7 is composed of alternating second high coercivity permanent magnet segments 701 and second low coercivity permanent magnet segments 702, and the first low coercivity permanent magnet segments 602 and the corresponding second low coercivity permanent magnet segments 702 are offset from each other by a predetermined mechanical angle in the circumferential direction.

[0032] It should be noted that both the first permanent magnet ring 6 and the second permanent magnet ring 7 employ an alternating arrangement of high-coercivity and low-coercivity permanent magnet segments. This provides the basic structural support for constructing the H-shaped bridge magnetic circuit unit, enabling the two types of permanent magnet segments to work synergistically to stabilize and adjust the magnetic field. The first low-coercivity permanent magnet segment 602 and the corresponding second low-coercivity permanent magnet segment 702 are offset from each other by a preset mechanical angle in the circumferential direction. This optimizes the spatial distribution of the air gap magnetic flux, reduces losses caused by magnetic flux fluctuations, and improves the stability of the motor during operation. It also ensures consistent response of each magnetic circuit unit during magnetic flux adjustment, guaranteeing the uniformity and reliability of the magnetic adjustment effect.

[0033] Furthermore, the first permanent magnet ring 6 and the second permanent magnet ring 7 each have no fewer than 40 segments, and the number of high coercivity permanent magnet segments is equal to the number of low coercivity permanent magnet segments.

[0034] It should be noted that the sufficient number of segments ensures that the magnetic bridge 8 can form an effective and uniform magnetic connection with each permanent magnet segment, allowing the magnetic flux of each unit to be smoothly connected in parallel during operation. During standby magnetization, the reversed low-coercivity segment can tightly "wrap" the magnetic flux of the adjacent high-coercivity segment through the magnetic bridge 8 and short-circuit it within the local loop, preventing magnetic flux leakage into the air gap. At the same time, the large number of segments means that the magnetic volume of each permanent magnet segment (especially the low-coercivity AlNiCo segment) is reduced, making its magnetization state easier to change with a limited magnetization field, reducing the difficulty of achieving saturated reverse magnetization, and improving the sensitivity and reliability of the magnetization response.

[0035] Furthermore, the preset mechanical angle between the first low coercivity permanent magnet segment 602 and the corresponding second low coercivity permanent magnet segment 702 is 9 degrees.

[0036] It should be noted that when each permanent magnet ring is composed of 40 permanent magnet segments (20 segments with high coercivity and 20 segments with low coercivity alternating), the center angle between two adjacent permanent magnet segments is 9 degrees. By staggering the low coercivity permanent magnet segments in the two layers of magnetic rings by this specific angle, it is essentially shifting the phase of the segments by "half a permanent magnet segment" in the circumferential direction. This allows the axial pulse magnetic field generated by the DC magnetic winding 2, which is not absolutely uniform in space, to achieve better coverage and complementarity in the circumferential direction when acting on the two staggered low coercivity permanent magnet segments.

[0037] Furthermore, the magnetic bridge 8, together with the first permanent magnet ring 6 and the second permanent magnet ring 7 on both sides, constitutes a plurality of H-shaped bridge magnetic circuit units distributed circumferentially; in each H-shaped bridge magnetic circuit unit, the two permanent magnet segments located on the same axial bridge arm have different coercivity, and the two permanent magnet segments located on the diagonal bridge arms have the same coercivity.

[0038] It should be noted that each H-shaped unit uses a section of the magnetic bridge 8 as a "crossbeam" and the corresponding permanent magnet sections on the two layers of permanent magnet rings axially connected at both ends as four "piers," thus forming a stable "H"-shaped magnetic flux path skeleton in three-dimensional space. The complex magnetic circuit control is decomposed into each unit, making the generation, collection, and short-circuit behavior of magnetic flux highly regular and controllable. Among them, the high coercivity permanent magnet section acts as the "stabilizer" and "magnetic potential base" of this branch, providing a strong and constant magnetomotive force that is difficult to change by external disturbances (such as armature reaction). The low coercivity permanent magnet section connected in series with it acts as the "magnetic potential regulating valve" of this branch, and its magnetic state can be sensitively changed by an external magnetic field. This series combination makes the total magnetomotive force of the bridge arm have both a high stability foundation and an adjustable "incremental" part, which is the key to achieving the coexistence of the contradictory characteristics of stable operating point and adjustable magnetic flux in the same magnetic circuit.

[0039] Furthermore, such as Figure 4 and Figure 5 As shown, when the DC magnetic winding 2 is not energized, the axial magnetization directions of all permanent magnet segments in the first permanent magnet ring 6 and the second permanent magnet ring 7 are the same. Within the same permanent magnet ring, the magnetic flux generated by the adjacent high coercivity permanent magnet segments and low coercivity permanent magnet segments is transmitted through the magnetic circuit of the magnetic bridge 8 and then converges on the magnetic housing and enters the main magnetic circuit composed of the magnetic housing, stator core and air gap in parallel.

[0040] It should be noted that when the DC magnetizing winding 2 is not energized, its core function is to cut off the source of the active magnetizing magnetic field. At this time, the motor relies entirely on the residual magnetism of the permanent magnet assembly itself to operate. Within the same permanent magnet ring, although adjacent high-coercivity permanent magnet sections and low-coercivity permanent magnet sections have different magnetic characteristics, their magnetization directions are the same and they are closely adjacent. The magnetic flux generated by each section will be emitted from within their respective sections and seek to enter the external magnetic circuit. At this time, the magnetic bridge 8 set between them plays a crucial role as a "magnetic flux collector" and "common bus". The magnetic bridge 8 is made of a high-permeability material, and its magnetic resistance is much lower than that of the air gap path. Therefore, the magnetic flux generated by two adjacent permanent magnets will preferentially enter the magnetic bridge 8 radially, and after being transmitted along the magnetic circuit of the magnetic bridge 8 axis, they will converge on the magnetic housing. The total magnetic flux that converges on the magnetic housing will then enter the main magnetic circuit composed of the magnetic housing, stator core and air gap in parallel. The specific path is as follows: the magnetic flux flows out of the magnetic bridge 8 and enters the magnetic housing that covers it. The magnetic housing guides the magnetic flux axially to the back of the stator core. The stator core then guides the magnetic flux radially to the toothed structure on its inner surface. Finally, the magnetic flux passes through the air gap and enters the rotor 1, forming a complete closed magnetic circuit, which provides the necessary excitation magnetic field for the electromechanical energy conversion of the motor.

[0041] Furthermore, such as Figure 6 As shown, when a current is passed into the DC magnetic winding 2 to cause the low coercivity permanent magnet segment to undergo reverse saturation magnetization, within a single permanent magnet ring, the low coercivity permanent magnet segment with reversed residual magnetism direction short-circuits the magnetic circuits of the two adjacent high coercivity permanent magnet segments in the circumferential direction through the magnetic bridge 8, so that the magnetic flux generated by the permanent magnet assembly no longer enters the air gap.

[0042] It should be noted that by passing a specific current through the DC magnetizing winding 2, a magnetizing magnetic field can be generated to saturate the low coercivity permanent magnet segment in the reverse direction, causing the remanence direction of the low coercivity permanent magnet segment to reverse. The magnetic bridge 8 provides a circumferential magnetic circuit channel for the reversed low coercivity permanent magnet segment, enabling it to form a closed short-circuit magnetic circuit with two adjacent high coercivity permanent magnet segments, changing the original magnetic flux transmission path. This short-circuit effect restricts the magnetic flux generated by the permanent magnet assembly to the local magnetic circuit it forms, preventing it from entering the air gap to participate in excitation, thereby cutting off the supply of air gap magnetic flux, eliminating iron loss in the standby state, and ensuring low-consumption operation of the motor in the non-working state.

[0043] Furthermore, the stator core includes a first stator core 301 and a second stator core 302 that are spaced apart along the axial direction of the rotor 1. The rotor 1 has salient poles at both ends, and the salient pole at one end of the rotor 1 and the corresponding salient pole at the other end are 180 electrical degrees apart in the axial direction.

[0044] It should be noted that the stator core is divided into two sections that are spaced apart along the axial direction of rotor 1. These sections can precisely match the salient poles at both ends of rotor 1, providing a clear axial transmission path for magnetic flux and ensuring the integrity and symmetry of the magnetic circuit.

[0045] This embodiment describes the working principle and usage method of an H-type bridge magnetic circuit adjustable flux induction sub-motor: This embodiment provides an H-type bridge magnetic circuit flux-adjustable induction motor. Through the synergistic effect of the H-type bridge magnetic circuit unit and the DC regulating winding 2, it achieves the dual goals of flux adjustment and stable operation. In the H-type unit formed by the magnetic bridge 8 and the first permanent magnet ring 6 and the second permanent magnet ring 7 on both sides, different coercive permanent magnet segments on the same axial bridge arm form a series connection. The high coercive permanent magnet segment provides a stable magnetomotive force basis, while the low coercive permanent magnet segment can flexibly change its magnetization state through an external magnetic field. When the DC regulating winding 2 is not energized, all permanent magnet segments are magnetized in the same direction. The magnetic flux of adjacent high and low coercive permanent magnet segments converges circumferentially through the magnetic bridge 8 and enters the main magnetic circuit in parallel, providing excitation flux for motor operation. At the same time, the high coercive permanent magnet segment stabilizes the operating point of the low coercive permanent magnet segment and resists the demagnetizing effect of the load current. When the DC tuning winding 2 is energized, the generated tuning magnetic field causes the low coercivity permanent magnet section to be reverse-saturated and magnetized. This magnetic field, through the magnetic bridge 8, short-circuits the magnetic circuit of the adjacent high coercivity permanent magnet section, confining the magnetic flux within the local magnetic circuit and preventing it from entering the air gap, thus completely eliminating standby iron loss. The structural design of the rotor 1 and the stator core optimizes the magnetic flux distribution, and the coaxial arrangement of all components ensures the smoothness and stability of magnetic flux transmission.

[0046] When starting up, disconnect the DC magnetizing winding 2. All permanent magnet segments in the permanent magnet assembly maintain their initial magnetization direction. The magnetic flux converges through the magnetic bridge 8 and enters the main magnetic circuit to provide excitation. The armature winding 5 realizes electromechanical energy conversion, and the motor enters normal operating condition. During operation, if it is necessary to adapt to different loads, a corresponding pulse current is applied to the DC magnetizing winding 2. The remanence of the low coercivity permanent magnet segment is changed by adjusting the magnetizing magnetic field, and the air gap magnetic flux amplitude is adjusted to match the load requirements. After magnetization is completed, the winding is immediately disconnected to avoid additional copper loss. It is necessary to switch to standby mode. In the current state, a specific pulse current is applied to the DC magnetic adjustment winding 2 to reverse saturate the low coercivity permanent magnet segment, and the magnetic circuit of the high coercivity permanent magnet segment is short-circuited through the magnetic bridge 8 to cut off the air gap magnetic flux supply, and the motor enters the low power standby mode. When restarting after standby, current is applied to the DC magnetic adjustment winding 2 again, and then immediately disconnected (pulse current) to reverse saturate the low coercivity permanent magnet segment, restore the low coercivity permanent magnet segment to its initial magnetization state, and the magnetic flux re-enters the main magnetic circuit through the magnetic bridge 8, so that the motor can start normally and start working.

[0047] It should be noted that, in terms of magnetic circuit design, this invention consists of 20 sets of H-shaped bridge units. Each H-shaped unit comprises two high-coercivity neodymium iron boron (NdFeB) permanent magnets, two low-coercivity AlNiCo (AlNiCo) permanent magnets, and a magnetic bridge 8. The permanent magnets on the same axial arm are made of different materials, while the permanent magnets on diagonal arms are made of the same material. Furthermore, to prevent magnetic saturation of the magnetic bridge 8 in the circumferential direction when the AlNiCo permanent magnets undergo reverse saturation magnetization, the thickness of the permanent magnets and the thickness of the magnetic bridge 8 must be equal, and the number of segments should be greater than or equal to 40.

[0048] Regarding the working mechanism of the H-type bridge magnetic circuit adjustable flux inductor memory motor: When the motor is in operation, the magnetic winding is open-circuited, and all permanent magnets are magnetized in the same direction. In each H-type bridge unit, AlNiCo and NdFeB permanent magnets on the same axis bridge arm provide magnetic flux in series, while excitation magnetic flux is provided to the motor in parallel between bridge arms on different axes. The excitation magnetic flux path at this time is: second layer permanent magnet ring - magnetic bridge 8 - first layer permanent magnet - first section of housing - first section of stator core 301 - air gap - rotor 1 - second section of stator core 302 - second section of housing. The specific magnetic circuit is as follows: Figure 4 As shown in (a), the air gap magnetic flux density is as follows Figure 7 The "Operating Status" marker line is shown in the diagram. Because high-coercivity permanent magnets have a stabilizing effect, they stabilize the operating point of the low-coercivity permanent magnets connected in series with them, thus preventing irreversible demagnetization of the low-coercivity permanent magnets due to the magnetic field generated by the load current, and improving the reliability of the motor.

[0049] In the motor standby state, in order to reduce the rotor 1 and air gap magnetic flux to 0Wb, a current is needed to be passed through the pulse magnetic adjustment winding to reverse-saturate the AlNiCo permanent magnet. The resulting magnetic adjustment magnetic field is as follows: Figure 5 (a) As shown by the dashed line, after the AlNiCo permanent magnet completes reverse magnetization, the magnetizing winding is disconnected to avoid copper loss. The magnetic flux direction of the permanent magnet is as follows: Figure 5 As shown in (b). In this H-type bridge unit, magnetic bridge 8 provides a circumferential short-circuit path for the permanent magnets. The low-coercivity AlNiCo permanent magnets in the same layer completely short-circuit the high-coercivity NdFeB permanent magnets. The magnetic flux generated by all permanent magnets will no longer enter rotor 1 through the housing, stator, and air gap. The corresponding magnetic circuit is as follows: Figure 6 As shown in (a) and 6(b), the air gap magnetic flux density at this time is as follows: Figure 7 As shown by the "standby state" marker line, the air gap magnetic flux density is basically equal to 0T, which can reduce the iron loss in standby to close to 0, thereby greatly improving the efficiency of the system.

[0050] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are only used to illustrate the technical solutions of the present invention, and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of protection of the present invention; those skilled in the art can understand the specific meaning of the above terms in the present invention according to the specific circumstances.

Claims

1. An H-type bridge-type magnetic circuit flux-adjustable induction sub-motor, characterized in that, include: The rotor (1), stator core, magnetic housing, permanent magnet assembly, and DC magnetic adjustment winding (2) are coaxially arranged; the stator core is sleeved on the outside of the rotor (1), and an armature winding (5) is provided in its inner ring; the magnetic housing is a first magnetic housing (401) and a second magnetic housing (402) corresponding to the outer sides of the first stator core (301) and the second stator core (302); the permanent magnet assembly is disposed on the first magnetic housing (401) and the second stator core (302). 1) Between the magnetic bridge (8) and the second section of the magnetic housing (402), there is a circular magnetic bridge (8) and a first permanent magnet ring (6) and a second permanent magnet ring (7) symmetrically arranged on both sides of the axial direction of the magnetic bridge (8); the first permanent magnet ring (6) and the second permanent magnet ring (7) are both composed of high coercivity permanent magnet segments and low coercivity permanent magnet segments arranged alternately and closely in the circumferential direction; the DC magnetic adjustment winding (2) is arranged in the inner circumferential direction of the magnetic bridge (8) inside the permanent magnet assembly.

2. The H-type bridge magnetic circuit flux-adjustable induction sub-motor as described in claim 1, characterized in that: The initial magnetization direction of the high coercivity permanent magnet segment and the low coercivity permanent magnet segment is axial magnetization, and their curvature, thickness, and length dimensions are completely consistent. In the initial working state, the initial remanence of the two segments is equal.

3. The H-type bridge magnetic circuit flux-adjustable induction sub-motor as described in claim 2, characterized in that: The high coercivity permanent magnet segment is made of neodymium iron boron permanent magnet, and the low coercivity permanent magnet segment is made of aluminum nickel cobalt permanent magnet.

4. The H-type bridge magnetic circuit flux-adjustable induction sub-motor as described in claim 2, characterized in that: The first permanent magnet ring (6) is composed of alternating first high coercivity permanent magnet segments (601) and first low coercivity permanent magnet segments (602); the second permanent magnet ring (7) is composed of alternating second high coercivity permanent magnet segments (701) and second low coercivity permanent magnet segments (702), and the first low coercivity permanent magnet segments (602) and the corresponding second low coercivity permanent magnet segments (702) are offset from each other by a preset mechanical angle in the circumferential direction.

5. The H-type bridge magnetic circuit flux-adjustable induction sub-motor as described in claim 4, characterized in that: The first permanent magnet ring (6) and the second permanent magnet ring (7) are each divided into no less than 40 segments, and the number of high coercivity permanent magnet segments is equal to the number of low coercivity permanent magnet segments.

6. The H-type bridge magnetic circuit flux-adjustable induction sub-motor as described in claim 5, characterized in that: The preset mechanical angle between the first low coercivity permanent magnet segment (602) and the corresponding second low coercivity permanent magnet segment (702) is 9 degrees.

7. The H-type bridge magnetic circuit flux-adjustable induction sub-motor as described in claim 1, characterized in that: The magnetic bridge (8) together with the first permanent magnet ring (6) and the second permanent magnet ring (7) on both sides constitute multiple H-shaped bridge magnetic circuit units distributed along the circumference; in each H-shaped bridge magnetic circuit unit, the two permanent magnet segments located on the same axial bridge arm have different coercivity, and the two permanent magnet segments located on the diagonal bridge arm have the same coercivity.

8. The H-type bridge magnetic circuit flux-adjustable induction sub-motor as described in claim 1, characterized in that: When the DC magnetic winding (2) is not energized, the axial magnetization directions of all permanent magnet segments in the first permanent magnet ring (6) and the second permanent magnet ring (7) are the same. Within the same permanent magnet ring, the magnetic flux generated by the adjacent high coercivity permanent magnet segments and low coercivity permanent magnet segments is transmitted through the magnetic bridge (8) axial magnetic circuit and then converges on the magnetic housing and enters the main magnetic circuit composed of the magnetic housing, stator core and air gap.

9. The H-type bridge magnetic circuit flux-adjustable induction sub-motor as described in claim 8, characterized in that: When a current is supplied to the DC magnetic winding (2) to cause the low coercivity permanent magnet segment to undergo reverse saturation magnetization, within a single permanent magnet ring, the low coercivity permanent magnet segment with reversed residual magnetism passes through the magnetic bridge (8) to short-circuit the magnetic circuits of the two adjacent high coercivity permanent magnet segments in the circumferential direction, so that the magnetic flux generated by the permanent magnet assembly no longer enters the air gap.

10. The H-type bridge magnetic circuit flux-adjustable induction sub-motor as described in claim 1, characterized in that: The stator core includes a first stator core (301) and a second stator core (302) spaced apart along the axial direction of the rotor (1). The rotor (1) has salient poles at both ends, and the salient pole at one end of the rotor (1) and the corresponding salient pole at the other end are 180 electrical degrees apart in the axial direction.

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