Electromagnetic force fluctuation suppression method and device of hybrid excitation motor, and linear motor

Abstract

The invention discloses an electromagnetic force fluctuation suppression method and device of a hybrid excitation motor and a linear motor, and aims to realize magnetic field adjustment of a transverse flux switching linear motor, reduce starting current and widen the speed regulation range of the motor. According to the electromagnetic force fluctuation suppression method, the amplitude, the frequency and the phase of the injected single-phase excitation current are calculated with the aim of introducing the excitation current with the minimum amplitude to suppress the permanent magnet thrust fluctuation to the maximum extent. Electromagnetic force fluctuation suppression can be carried out on the hybrid excitation motor with three-phase sine alternating current introduced into the armature winding by introducing single-phase excitation current into the excitation winding. Permanent magnet thrust fluctuation generated by interaction of the permanent magnet and the armature winding is suppressed by electromagnetic force generated by interaction of the excitation winding and the armature winding, high electromagnetic force density can be maintained while electromagnetic force fluctuation can be effectively reduced, and the injected single-phase excitation current is irrelevant to amplitude and phase of armature current, so that the permanent magnet thrust fluctuation is suppressed. The control method is simple.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of motor control, and particularly relates to a hybrid excitation motor electromagnetic force fluctuation suppression method and device and a linear motor. BACKGROUND

[0002] Rare earth permanent magnet motor has the advantages of high power density and high efficiency, but due to the existence of only a single permanent magnet excitation source inside, it brings the inherent problem of magnetic field regulation difficulty. Hybrid excitation motor organically combines permanent magnet magnetic motive force and electric excitation magnetic motive force, and is a new type of core component for realizing high-performance power generation and driving system.

[0003] At present, the research on hybrid excitation motor is focused on using excitation winding to widen the speed range of the motor or solving the problem of back electromotive force impact in the fault state of permanent magnet motor high-speed operation, but there are the following methods and shortcomings in the electromagnetic force fluctuation suppression strategy of hybrid excitation motor: first, the method of optimizing the structure parameters of the motor such as the magnetic bridge structure is adopted, but the change of the structure may increase the volume of the motor or increase the processing difficulty of the motor, and the electromagnetic force fluctuation suppression cannot be performed on the motor with determined structure parameters; second, the torque closed-loop control strategy is adopted, but it leads to the increase of devices and cost; third, the harmonic injection method of injecting three-phase harmonic armature current into the armature winding is adopted, but the amplitude of the harmonic current is proportional to the amplitude of the armature current, which needs to be adjusted with the change of the armature current, leading to the increase of control difficulty.

[0004] The existing method fails to fully utilize the potential of excitation winding as an independent magnetic source for targeted electromagnetic force fluctuation suppression, and there is an irreconcilable contradiction in dynamic adaptability, cost efficiency and control simplicity.

[0005] Therefore, in order to solve one or more problems in the related technical solutions, the present application proposes a motor control method for hybrid excitation motor electromagnetic force fluctuation suppression, which does not need to optimize the motor structure, only calculates through the motor structure parameters and magnetic circuit, and passes a single-phase excitation current in the excitation winding which is irrelevant to the amplitude and phase of the armature current.

[0006] When driving a linear motion load, the linear motor saves the conversion mechanism from rotation to linear motion of the rotary motor, so it has the advantages of simple overall structure, high position accuracy, fast response speed and low noise, which improves the efficiency of the whole system. In recent years, with the increasing application of linear driving, linear motor has gradually become one of the research and development hotspots, and has been widely used in military industry, aerospace, rail transportation, electromagnetic catapult and other fields.

[0007] Transverse flux-switched permanent magnet linear motors (TFSPMLMs) possess excellent characteristics such as high thrust density, simple secondary-side structure, phase isolation and decoupling, electromagnetic independence, flexible design, and convenient control. Their application areas are increasingly expanding, especially suitable for low-speed, high-power drive applications. Transverse flux-switched permanent magnet linear motors significantly shorten the magnetic circuit length, reduce the amount of ferromagnetic material and iron loss, and increase the rate of change of magnetic energy within a certain range, thereby increasing the motor's output. However, the presence of only a single permanent magnet excitation source within the TFSPMLM introduces inherent problems related to difficult magnetic field adjustment, limiting its motoring speed range, high-efficiency zone expansion, and voltage regulation and fault protection capabilities during generator operation. Furthermore, the relatively large primary mass of this motor leads to excessively high starting current.

[0008] Therefore, in order to achieve magnetic field regulation of the transverse flux switching linear motor, reduce the starting current, widen the speed range of the motor, and enhance the voltage regulation and fault protection capabilities of the power generation operation, this invention proposes a hybrid excitation transverse flux switching linear motor as a solution to the above problems. Summary of the Invention

[0009] The purpose of this invention is to provide a method and apparatus for suppressing electromagnetic force fluctuations in a hybrid excitation motor and a linear motor, in order to solve the aforementioned technical problems.

[0010] This invention is implemented according to the following technical solution:

[0011] In a first aspect, the present invention provides a method for suppressing electromagnetic force fluctuations in a hybrid excitation motor, wherein the hybrid excitation motor is a hybrid excitation linear motor or a hybrid excitation rotary motor, and the method includes: constructing a mathematical decoupling model of the electromagnetic force of the hybrid excitation motor using the magnetic co-energy method and the Fourier decomposition method; the variables of the mathematical decoupling model of the electromagnetic force of the hybrid excitation motor include the magnetomotive force and the rate of change of magnetic permeability of the magnetic source; the magnetic source includes a permanent magnet, an armature winding, and an excitation winding;

[0012] The self-inductance and mutual inductance of each magnetic source are calculated as a function of mover displacement or rotor rotation. The curves are differentiated and harmonic analyzed to extract the characteristic quantity of the rate of change of mutual inductance of each magnetic source. The mutual inductance of each magnetic source includes: the mutual inductance of permanent magnet and armature winding, and the mutual inductance of excitation winding and armature winding.

[0013] Substituting the characteristic quantity of the mutual inductance rate of change of permanent magnet and armature winding into the mathematical decoupling model of electromagnetic force of hybrid excitation motor, the characteristic quantity of permanent magnet thrust fluctuation is obtained; the characteristic quantity of permanent magnet thrust fluctuation includes the amplitude, frequency and phase of the fundamental wave and each harmonic.

[0014] Define the expression for the single-phase excitation current injected into the excitation winding and the corresponding expression for the magnetomotive force of the excitation winding.

[0015] Substituting the defined characteristic quantities of the magnetomotive force of the excitation winding and the rate of change of mutual inductance of the excitation winding and the armature winding into the mathematical decoupling model of electromagnetic force of the hybrid excitation motor, we can obtain the characteristic quantities of electromagnetic force generated by the interaction of excitation current and armature current.

[0016] With the optimization objective of minimizing the amplitude of the single-phase excitation current and maximizing the suppression of permanent magnet thrust fluctuations, the single-phase excitation current injected into the excitation winding is solved.

[0017] Injecting a single-phase excitation current into the excitation winding allows the electromagnetic force generated by the interaction between the excitation winding and the armature winding to suppress the permanent magnet thrust fluctuations generated by the interaction between the permanent magnet and the armature winding, thus achieving electromagnetic force fluctuation suppression.

[0018] In one embodiment, the electromagnetic force mathematical decoupling model of the hybrid excitation motor is as follows:

[0019]

[0020] Among them, F P F represents the magnetomotive force of a permanent magnet. A F represents the magnetomotive force of the armature winding. F Λ represents the magnetomotive force of the excitation winding. P Indicates the self-inductance of a permanent magnet, Λ A Indicates the self-inductance of the armature winding, Λ F Indicates the self-inductance of the excitation winding, Λ PA Λ represents the mutual inductance of the permanent magnet and the armature winding. FA Λ represents the mutual inductance of the excitation winding and the armature winding. PF denoted by , which represents the mutual inductance of the permanent magnet and the excitation winding, and x represents the distance of displacement of the motor mover or the angle of rotation of the rotor.

[0021] In one embodiment, the characteristic quantities of the rate of change of magnetic permeability include the amplitude, frequency, and phase of the fundamental wave and each harmonic of the magnetic permeability.

[0022] In one embodiment, the characteristic quantity of the rate of change of mutual inductance between the permanent magnet and the armature winding is:

[0023]

[0024] Among them, A PAn denoted as δ, where δ is the amplitude of the nth harmonic of the mutual inductance between the permanent magnet and the armature winding, w is the angular frequency of the motor, v is the speed of the motor mover, and δ is the fundamental phase angle of the rate of change of mutual inductance between the permanent magnet and the armature winding (phase A).

[0025] In one embodiment, the average thrust component is removed from the mathematical expression of the permanent magnet thrust characteristic quantity to obtain the permanent magnet thrust fluctuation characteristic quantity, wherein the mathematical expression of the permanent magnet thrust characteristic quantity is:

[0026]

[0027] in, F is the characteristic quantity of permanent magnet thrust. a F b and F c These are the magnetomotive forces of the three-phase armature windings, F P Λ represents the magnetomotive force of a permanent magnet. Pa Λ Pb and Λ Pc These are the mutual inductance of the permanent magnet and the three-phase armature winding, respectively.

[0028] When the amplitudes of the 5th and 7th harmonics of the mutual inductance permeability change rate are constant, the expression for the characteristic quantity of permanent magnet thrust fluctuation is:

[0029]

[0030] Among them, A PA5 and A PA7 These are the 5th and 7th harmonic amplitudes of the rate of change of mutual inductance of the permanent magnet and the armature winding, respectively. This represents the amplitude of the armature winding magnetomotive force.

[0031] In one embodiment, the characteristic quantity of the electromagnetic force generated by the interaction between the excitation winding and the armature winding is:

[0032]

[0033] Among them, Λ Fa Λ Fb and Λ Fc These are the mutual inductance of the excitation winding and the three-phase armature winding, respectively.

[0034] In one implementation, the expression for the single-phase excitation current is defined as:

[0035]

[0036] Among them, i F For the excitation current, I F φ is the amplitude of the excitation current, t is the ratio of the excitation current frequency to the armature current frequency, and φ is the phase of the excitation current.

[0037] The expression for the magnetomotive force of the excitation winding is defined as follows:

[0038]

[0039] Where, NF F is the number of turns in the excitation winding. f This represents the amplitude of the excitation magnetomotive force.

[0040] In one embodiment, the characteristic quantity of the rate of change of mutual inductance of the excitation winding and the armature winding is:

[0041]

[0042] Among them, A FAn δ is the amplitude of the nth harmonic of the mutual inductance of the excitation winding and the armature winding, w is the angular frequency of the motor, v is the speed of the motor mover, δ is the fundamental phase angle of the rate of change of mutual inductance of the permanent magnet and the armature winding A phase, and x represents the distance of the motor mover displacement or the angle of the rotor rotation.

[0043] When the rate of change of mutual inductance is the amplitude of the 5th and 7th harmonics, the expression for the characteristic quantity of the electromagnetic force generated by the interaction of the excitation current and armature current is:

[0044]

[0045] in, The fundamental amplitude of the rate of change of mutual inductance permeability. This represents the amplitude of the armature winding magnetomotive force. This represents the magnetomotive force amplitude of the excitation winding.

[0046] Secondly, the present invention provides an electromagnetic force fluctuation suppression device for a hybrid excitation motor. The device includes: a hybrid excitation motor electromagnetic force mathematical decoupling model module, used to construct a hybrid excitation motor electromagnetic force mathematical decoupling model using the magnetic co-energy method and the Fourier decomposition method; the variables of the hybrid excitation motor electromagnetic force mathematical decoupling model include the magnetomotive force and the rate of change of magnetic permeability of the magnetic source; the magnetic source includes a permanent magnet, an armature winding, and an excitation winding.

[0047] The characteristic quantity extraction module for the rate of change of magnetic permeability is used to calculate the curves of the self-inductance and mutual inductance of each magnetic source as a function of the mover displacement or the rotor rotation, and to perform differentiation and harmonic analysis on the curves to extract the characteristic quantity of the rate of change of mutual inductance of each magnetic source; the mutual inductance of each magnetic source includes: the mutual inductance of the permanent magnet and the armature winding, and the mutual inductance of the excitation winding and the armature winding.

[0048] The permanent magnet thrust fluctuation characteristic quantity calculation module is used to substitute the characteristic quantity of the mutual inductance permeability change rate between the permanent magnet and the armature winding into the electromagnetic force mathematical decoupling model of the hybrid excitation motor to obtain the permanent magnet thrust fluctuation characteristic quantity; the permanent magnet thrust fluctuation characteristic quantity includes the amplitude, frequency and phase of the fundamental wave and each harmonic.

[0049] The definition module is used to define the expression for the single-phase excitation current injected into the excitation winding and the corresponding magnetomotive force expression of the excitation winding.

[0050] The electromagnetic force characteristic quantity calculation module is used to substitute the defined characteristic quantities of the magnetomotive force of the excitation winding and the rate of change of mutual inductance of the excitation winding and the armature winding into the electromagnetic force mathematical decoupling model of the hybrid excitation motor to obtain the electromagnetic force characteristic quantity generated by the interaction of the excitation current and the armature current.

[0051] The optimization module is used to solve for the single-phase excitation current injected into the excitation winding with the optimization objectives of minimizing the excitation current amplitude and maximizing the suppression of permanent magnet thrust fluctuations.

[0052] The single-phase excitation current injection module is used to inject single-phase excitation current into the excitation winding, so that the electromagnetic force generated by the interaction between the excitation winding and the armature winding can suppress the permanent magnet thrust fluctuation generated by the interaction between the permanent magnet and the armature winding, thereby achieving electromagnetic force fluctuation suppression.

[0053] Thirdly, the present invention provides a hybrid excitation transverse flux switching linear motor, comprising a primary part and a secondary part, wherein the secondary part is arranged in the primary part and the two parts are capable of relative displacement.

[0054] The primary section is composed of multiple primary units with the same structure arranged side by side in a uniform manner. The primary unit includes a primary magnetic conductor, an excitation winding, an armature winding, and a permanent magnet. The yoke of the primary magnetic conductor forms a magnetic bridge.

[0055] The primary magnetic conductive component has a U-shaped structure, with four protruding teeth I evenly spaced along the entire circumference on its inner ring surface. Each protruding tooth I is equipped with a permanent magnet to form a magnetic pole, and the armature winding is wound around the magnetic pole.

[0056] The primary magnetic conductive component has four grooves evenly spaced along the entire circumference on its side surface, and the excitation winding is wound in the grooves.

[0057] The secondary part consists of a fixed shaft and a plurality of secondary magnetic conductive components arranged and fixed on the fixed shaft in sequence; when a secondary magnetic conductive component is aligned with a primary unit, there will be a plurality of air gaps between them.

[0058] In one embodiment, the plurality of secondary magnetic conductive components are formed by alternating two types of secondary magnetic conductive components I and secondary magnetic conductive components II, which have mirror-like structures.

[0059] Both the secondary magnetic conductive component I and the secondary magnetic conductive component II are provided with four protruding teeth II, and one protruding tooth II corresponds to one protruding tooth I. The air gap is formed between the protruding teeth I and the protruding teeth II, and thus there are four oblique air gaps evenly distributed in the circumferential direction between the primary unit and the secondary magnetic conductive component.

[0060] When the secondary magnetic conductive component I is aligned with the primary unit, the secondary magnetic conductive component II cannot be aligned with the primary unit; when the secondary magnetic conductive component II is aligned with the primary unit, the secondary magnetic conductive component I cannot be aligned with the primary unit; the positions of the four oblique air gaps formed when the secondary magnetic conductive component I is aligned with the primary unit are different from the positions of the four oblique air gaps formed when the secondary magnetic conductive component II is aligned with the primary unit.

[0061] In one embodiment, the four oblique air gaps are denoted as air gap A, air gap B, air gap C and air gap D along the circumference. Air gap A and air gap C are parallel and centrally symmetrically distributed, and air gap B and air gap D are parallel and centrally symmetrically distributed.

[0062] When the primary unit interacts with the secondary magnetic components, the forces in the two pairs of air gaps formed by air gaps A and C, and air gaps B and D, pass through the center of the circle and are in opposite directions, which can eliminate the tangential torque during motor operation.

[0063] In one embodiment, when the magnetic flux circuit of the excitation winding is connected in parallel with the magnetic flux circuit of the permanent magnet and the magnetic flux direction is consistent at the alignment position of the tooth I of the primary magnetic guiding component and the tooth II of the secondary magnetic guiding component, the air gap magnetic flux density is improved.

[0064] When a relative displacement occurs between the secondary part and the primary part, and the alignment of the secondary magnetic guide component I with the primary unit is changed to the alignment of the secondary magnetic guide component II with the primary unit, the permanent magnet and the excitation winding generate magnetic flux in different directions in the winding, and a corresponding induced electromotive force will be induced in the armature winding. When a changing current is applied to the winding, a thrust will be generated.

[0065] In one embodiment, an excitation winding is wound on the primary magnetic conductor between two adjacent grooves; or, the excitation winding is wound in a loop structure in the four grooves.

[0066] Beneficial effects of this invention:

[0067] 1) The parallel connection of the permanent magnet and the excitation winding magnetic circuit enhances the motor's magnetic flux regulation capability and reduces the risk of irreversible demagnetization of the permanent magnet;

[0068] 2) The magnetic bridge structure improves the magnetic flux adjustment capability, ensures the integrity of the stator core, and is easy to process;

[0069] 3) The motor adopts a transverse flux structure, which has the characteristics of high torque density, flexible design, electromagnetic load decoupling, convenient control, excellent low-speed characteristics, and high efficiency;

[0070] 4) The motor can adopt an irregular air gap structure to increase the air gap area, which enhances the mutual inductance between the equivalent permanent magnet winding and the armature winding, as well as the mutual inductance between the excitation winding and the armature winding. At the same time, since the air gap is centrally symmetrically distributed, it can offset unnecessary tangential torque, reduce the difficulty of fixing the motor and extend the service life of the motor.

[0071] 5) The excitation winding coil can adopt a loop structure, which reduces the amount of copper used in the motor and lowers the manufacturing cost;

[0072] 6) Each primary unit is independent of the others, resulting in high motor reliability and strong fault tolerance.

[0073] 7) The electromagnetic force fluctuation suppression method of this application uses the magnetic co-energy method and Fourier decomposition method to construct a mathematical decoupling model of electromagnetic force of hybrid excitation motor, and equates the excitation winding and armature winding to magnetic sources, and reduces the motor control parameters to motor structural parameters, and establishes the mapping relationship between electromagnetic forces such as motor positioning force, electromagnetic thrust generated by the interaction of magnetic sources, and magnetic reluctance generated by winding current and motor topology parameters under multiple magnetic sources.

[0074] 8) In the electromagnetic force fluctuation suppression method of this application, a single-phase excitation current can be passed through the excitation winding to suppress electromagnetic force fluctuations in a hybrid excitation motor in which a three-phase sinusoidal alternating current is passed through the armature winding, thereby greatly reducing the control difficulty and saving device costs.

[0075] 9) In the electromagnetic force fluctuation suppression method of this application, the single-phase excitation current supplied to the excitation winding is independent of the amplitude and phase of the three-phase armature current, and is only related to the permanent magnet, motor structural parameters, number of winding turns and magnetic circuit. That is, when the amplitude and phase of the armature current are changed, the single-phase excitation current supplied does not need to be changed. Therefore, the single-phase excitation current supplied can be applied to various operating scenarios under different three-phase armature current conditions.

[0076] 10) The electromagnetic force fluctuation suppression method of this application is applicable to motor control strategies where there is an arbitrary phase difference between armature current and no-load induced electromotive force, and has universality. Attached Figure Description

[0077] The accompanying drawings, as part of this invention, are provided to further illustrate the invention. The illustrative embodiments and descriptions of the invention are used to explain the invention, but do not constitute an undue limitation thereof. Clearly, the drawings described below are merely some embodiments, and those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0078] Figure 1 A flowchart illustrating an electromagnetic force fluctuation suppression method for a hybrid excitation motor according to an embodiment of the present invention;

[0079] Figure 2 The waveform and harmonic analysis diagram of the mutual inductance rate of change of permanent magnet and armature winding provided in one embodiment of the present invention;

[0080] Figure 3 The waveform and harmonic analysis diagram of the mutual inductance rate of the excitation winding and the armature winding provided in one embodiment of the present invention are shown.

[0081] Figure 4 The electromagnetic force waveform before the excitation current is injected;

[0082] Figure 5 The image shows the electromagnetic force waveform after single-phase excitation current injection using the method of this invention.

[0083] Figure 6 These are schematic diagrams of two structures of a hybrid excitation transverse flux switching linear motor according to the present invention, wherein... Figure 6 (a) represents the first structure. Figure 6 (b) represents the second structure;

[0084] Figure 7 This is a schematic diagram of the end structure of a hybrid excitation transverse flux switching linear motor according to the present invention, and a schematic diagram of the magnetization direction of the primary permanent magnet.

[0085] Figure 8 This is a schematic diagram of the primary unit structure of a hybrid excitation transverse flux switching linear motor according to the present invention;

[0086] Figure 9 This is a schematic diagram of the secondary magnetic conductor structure of a hybrid excitation transverse flux switching linear motor according to the present invention, wherein... Figure 9 (a) is secondary magnetic component I. Figure 9 (b) is the secondary magnetic conductive component II;

[0087] Figure 10 This is a schematic diagram of the secondary structure of a hybrid excitation transverse flux switching linear motor according to the present invention, wherein... Figure 10 (a) Front view, Figure 10 (b) is a sub-stereoscopic view;

[0088] Figure 11 This is a schematic diagram of the magnetic flux flow direction when the secondary magnetic guiding component is aligned with the primary unit in the magnetized state of a hybrid excitation transverse flux switching linear motor according to the present invention. Figure 11 (a) shows the magnetic flux flow direction when the secondary magnetic conductor I is aligned with the primary unit. Figure 11 (b) shows the direction of magnetic flux flow when the secondary magnetic conductive component II is aligned with the primary unit;

[0089] Figure 12This is a schematic diagram of the magnetic flux flow direction when the secondary magnetic guiding component is aligned with the primary unit in the demagnetized state of a hybrid excitation transverse flux switching linear motor according to the present invention. Figure 12 (a) shows the magnetic flux flow direction when the secondary magnetic conductor I is aligned with the primary unit. Figure 12 (b) shows the direction of magnetic flux flow when the secondary magnetic component II is aligned with the primary unit.

[0090] Figure labels: 1-Primary magnetic conductor, 2-Permanent magnet, 3-Armature winding, 4-Secondary magnetic conductor I, 5-Secondary magnetic conductor II, 6-Fixed shaft, 7-Excitation winding.

[0091] 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

[0092] 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.

[0093] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments will be clearly and completely described below with reference to the accompanying drawings. The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0094] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0095] Reference Figure 1 As shown in one embodiment, a method for suppressing electromagnetic force fluctuations in a hybrid excitation motor is provided. The hybrid excitation motor is a hybrid excitation transverse flux switching linear motor. The method includes the following steps:

[0096] Step S100: Construct a mathematical decoupling model of electromagnetic force for a hybrid excitation motor using the magnetic co-energy method and Fourier decomposition method.

[0097] The establishment of the electromagnetic force mathematical decoupling model of the hybrid excitation motor is based on the positioning force generated by the permanent magnet itself, the magnetic reluctance generated by the excitation winding itself, the magnetic reluctance generated by the armature winding itself, the electromagnetic force generated by the interaction between the permanent magnet and the excitation winding, the permanent magnet thrust generated by the interaction between the permanent magnet and the armature winding, and the electromagnetic force generated by the interaction between the excitation winding and the armature winding.

[0098] Furthermore, the core variables in the mathematical decoupling model of the electromagnetic force of the hybrid excitation motor include the magnetomotive force and the rate of change of magnetic permeability of the magnetic source. The magnetic source includes permanent magnets, armature windings, and excitation windings.

[0099] Furthermore, the mathematical decoupling model expression for the electromagnetic force of the hybrid excitation motor is as follows:

[0100] (1)

[0101] Among them, F P F represents the magnetomotive force of a permanent magnet. A F represents the magnetomotive force of the armature winding. F Λ represents the magnetomotive force of the excitation winding. P Indicates the self-inductance of a permanent magnet, Λ A Indicates the self-inductance of the armature winding, Λ F Indicates the self-inductance of the excitation winding, Λ PA Λ represents the mutual inductance of the permanent magnet and the armature winding. FA Λ represents the mutual inductance of the excitation winding and the armature winding. PF denoted by , which represents the mutual inductance of the permanent magnet and the excitation winding, and x represents the distance of displacement of the motor mover or the angle of rotation of the rotor.

[0102] This invention is applicable not only to hybrid excitation linear motors, but also to hybrid excitation rotary motors. It is only necessary to change the distance of the mover displacement in formula (1) to the angle of rotor rotation.

[0103] Step S200: Calculate the curves of the self-inductance and mutual inductance of each magnetic source as a function of the mover displacement or the rotor rotation, and perform differentiation and harmonic analysis on the curves to extract the characteristic quantity of the mutual inductance rate of change.

[0104] Furthermore, the characteristic quantities of the rate of change of magnetic permeability include the amplitude, frequency, and phase of the fundamental wave and each harmonic of the magnetic permeability.

[0105] Furthermore, the self-inductance and mutual inductance of each magnetic source are calculated as a function of mover displacement or rotor rotation using the equivalent magnetic network method, analytical method, or finite element simulation. The curves are then differentiated and analyzed using first-order differentiation and Fourier harmonic analysis.

[0106] Furthermore, the magnetomotive force of the magnetic source includes: permanent magnet magnetomotive force, excitation winding magnetomotive force and armature winding magnetomotive force, and the magnetic permeability includes the mutual inductance of each magnetic source.

[0107] Furthermore, the mutual inductance of each magnetic source includes: the mutual inductance of the permanent magnet and the armature winding, the mutual inductance of the excitation winding and the armature winding, and the permanent magnet.

[0108] The characteristic quantity of the rate of change of mutual inductance between the permanent magnet and the armature winding is:

[0109] (2)

[0110] Among them, A PAn denoted as δ, where δ is the amplitude of the nth harmonic of the mutual inductance between the permanent magnet and the armature winding, w is the angular frequency of the motor, v is the speed of the motor mover, and δ is the fundamental phase angle of the rate of change of mutual inductance between the permanent magnet and the armature winding (phase A).

[0111] The characteristic quantity of the rate of change of mutual inductance permeability between the excitation winding and the armature winding is:

[0112] (3)

[0113] Among them, A FAn It represents the amplitude of the nth harmonic of the mutual inductance between the excitation winding and the armature winding.

[0114] The expression for the armature winding magnetomotive force is:

[0115] (4)

[0116] Where, N a N b and N c These represent the number of turns in the three-phase armature winding, i a i b and i c These are the currents of the three-phase armature windings, I m Ψ is the amplitude of the armature current, and Ψ is the phase difference between the armature current and the no-load induced electromotive force.

[0117] In an optional embodiment, the magnetic permeability includes a characteristic quantity of the rate of change of self-inductance of each magnetic source, and the self-inductance of each magnetic source includes: the self-inductance of the magnet, the self-inductance of the armature winding, and the self-inductance of the excitation winding; the mutual inductance of each magnetic source also includes: the mutual inductance of the permanent magnet and the excitation winding.

[0118] In this invention, which focuses on suppressing permanent magnet thrust fluctuations using excitation current, the main focus is on and utilization of the characteristic quantities of the mutual inductance rate of change between the permanent magnet and the armature winding, and the characteristic quantities of the mutual inductance rate of change between the excitation winding and the armature winding. The calculation of other permeability rate characteristic quantities may be necessary for the completeness of the method and can be used to analyze other force components of the motor or different control objectives (such as suppressing positioning force), but they are not core dependencies of this suppression method.

[0119] Step S300: Substitute the characteristic quantity of the mutual inductance rate of change of permanent magnet and armature winding into the mathematical decoupling model of electromagnetic force of hybrid excitation motor to obtain the characteristic quantity of permanent magnet thrust fluctuation.

[0120] Furthermore, the characteristic quantities of permanent magnet thrust fluctuation include: the amplitude, frequency, and phase of the fundamental wave and each harmonic of permanent magnet thrust fluctuation.

[0121] The average thrust component is removed from the mathematical expression of the permanent magnet thrust characteristic quantity to obtain the permanent magnet thrust fluctuation characteristic quantity. The mathematical expression of the permanent magnet thrust characteristic quantity is as follows:

[0122] (5)

[0123] in, F is the characteristic quantity of permanent magnet thrust. a F b and F c These are the magnetomotive forces of the three-phase armature windings, Λ Pa Λ Pb and Λ Pc These are the mutual inductance of the permanent magnet and the three-phase armature winding, respectively.

[0124] Step S400: Define the expression for the single-phase excitation current injected into the excitation winding and the corresponding expression for the magnetomotive force of the excitation winding.

[0125] Furthermore, the expression for single-phase excitation current is defined as follows:

[0126] (6)

[0127] Among them, i F For the excitation current, I F φ is the amplitude of the excitation current, t is the frequency of the excitation current, and φ is the phase of the excitation current.

[0128] Furthermore, the expression for the magnetomotive force of the excitation winding is defined as follows:

[0129] (7)

[0130] Where, N F F is the number of turns in the excitation winding. f This represents the amplitude of the excitation magnetomotive force.

[0131] Step S500: Substitute the defined characteristic quantities of the magnetomotive force of the excitation winding and the rate of change of mutual inductance of the excitation winding and the armature winding into the mathematical decoupling model of electromagnetic force of the hybrid excitation motor to obtain the characteristic quantity of electromagnetic force generated by the interaction of excitation current and armature current.

[0132] Specifically, the fundamental frequency and the fifth and seventh harmonics account for the largest proportion of the characteristic quantities.

[0133] Furthermore, the characteristic quantity of the electromagnetic force generated by the interaction between the excitation winding and the armature winding is:

[0134] (8)

[0135] Among them, Λ Fa Λ Fb and Λ Fc These are the mutual inductance of the excitation winding and the three-phase armature winding, respectively.

[0136] Step S600: With the optimization objective of minimizing the amplitude of the single-phase excitation current and maximizing the suppression of permanent magnet thrust fluctuations, solve for the single-phase excitation current injected into the excitation winding.

[0137] Furthermore, with the optimization objective of minimizing the amplitude of the single-phase excitation current and maximizing the suppression of permanent magnet thrust fluctuations, f FA The term containing the fundamental wave of the mutual inductance rate of change between the excitation winding and the armature winding is equal to the expression of the characteristic quantity of the permanent magnet thrust fluctuation, and the single-phase excitation current injected into the excitation winding is solved.

[0138] When the rate of change of mutual inductance permeability is the amplitude of the 5th and 7th harmonics, the calculated amplitude of the single-phase excitation current is expressed as:

[0139] (9)

[0140] Step S700: Inject single-phase excitation current into the excitation winding, so that the electromagnetic force generated by the interaction between the excitation winding and the armature winding can suppress the permanent magnet thrust fluctuation generated by the interaction between the permanent magnet and the armature winding, thereby achieving electromagnetic force fluctuation suppression.

[0141] In one specific embodiment, a three-phase, six-primary-unit transverse flux-switching hybrid excitation linear motor is selected. The amplitude, frequency, and phase of the fundamental and harmonic frequencies of the mutual inductance rate of change between the permanent magnet and the armature winding are obtained using technical means, such as... Figure 2 As shown, the main components are the fundamental frequency and the 3rd, 5th, and 7th harmonics; the amplitude, frequency, and phase of the fundamental frequency and each harmonic of the mutual inductance rate of the excitation winding and armature winding, obtained using technical means, are shown below. Figure 3As shown, the main components are the fundamental frequency and the 3rd, 5th, and 7th harmonics; the motor's operating speed is 1 m / s, the effective value of the armature current is 5 A, the frequency is 2p / 0.03, and the phase difference Ψ between the armature current and the no-load induced electromotive force is 0, i.e., using i d =0 control method, armature winding turns are 75, excitation winding turns are 20, and the initial position of the mover is set to the position where the fundamental phase angle δ of the mutual inductance rate of change between the permanent magnet and the armature winding A phase is 0.

[0142] Substituting formulas (2) and (4) into (5) and removing the average thrust, the permanent magnet thrust fluctuation characteristic is calculated as follows:

[0143] (10)

[0144] Among them, A PA5 and A PA7 These are the 5th and 7th harmonic amplitudes of the mutual inductance rate of change of the permanent magnet and the armature winding, respectively.

[0145] Substituting equations (3) and (7) into equation (8), the characteristic quantity of the electromagnetic force generated by the interaction between the excitation current and the armature current is:

[0146] (11)

[0147] The calculated amplitude of the single-phase excitation current is:

[0148] (12) frequency t It is 6, phase φ for .

[0149] Figure 4 This is a waveform diagram of the electromagnetic force before the excitation current is injected. Figure 5 The image shows the electromagnetic force waveform after single-phase excitation current injection using the method of this invention. Figure 4 and Figure 5 It can be seen that the electromagnetic force fluctuation decreased from 9.48N to 2.36N, a reduction of 75%, while the average electromagnetic force remained essentially unchanged, decreasing from 93.4N to 93.3N. Therefore, the method of this invention can effectively reduce electromagnetic force fluctuation while maintaining a high electromagnetic force density.

[0150] In one embodiment, an electromagnetic force fluctuation suppression device for a hybrid excitation motor is proposed. The device includes: a mathematical decoupling model module for the electromagnetic force of the hybrid excitation motor, used to construct a mathematical decoupling model for the electromagnetic force of the hybrid excitation motor using the magnetic co-energy method and the Fourier decomposition method; the variables of the mathematical decoupling model for the electromagnetic force of the hybrid excitation motor include the magnetomotive force and the rate of change of magnetic permeability of the magnetic source; the magnetic source includes a permanent magnet, an armature winding, and an excitation winding; The characteristic quantity extraction module for the rate of change of magnetic permeability is used to calculate the curves of the self-inductance and mutual inductance of each magnetic source as a function of the mover displacement or the rotor rotation, and to perform differentiation and harmonic analysis on the curves to extract the characteristic quantity of the rate of change of mutual inductance of each magnetic source; the mutual inductance of each magnetic source includes: the mutual inductance of the permanent magnet and the armature winding, and the mutual inductance of the excitation winding and the armature winding. The permanent magnet thrust fluctuation characteristic quantity calculation module is used to substitute the characteristic quantity of the mutual inductance permeability change rate between the permanent magnet and the armature winding into the electromagnetic force mathematical decoupling model of the hybrid excitation motor to obtain the permanent magnet thrust fluctuation characteristic quantity; the permanent magnet thrust fluctuation characteristic quantity includes the amplitude, frequency and phase of the fundamental wave and each harmonic. The definition module is used to define the expression for the single-phase excitation current injected into the excitation winding and the corresponding magnetomotive force expression of the excitation winding. The electromagnetic force characteristic quantity calculation module is used to substitute the defined characteristic quantities of the magnetomotive force of the excitation winding and the rate of change of mutual inductance of the excitation winding and the armature winding into the electromagnetic force mathematical decoupling model of the hybrid excitation motor to obtain the electromagnetic force characteristic quantity generated by the interaction of the excitation current and the armature current. The optimization module is used to solve for the single-phase excitation current injected into the excitation winding with the optimization objectives of minimizing the excitation current amplitude and maximizing the suppression of permanent magnet thrust fluctuations. The single-phase excitation current injection module is used to inject single-phase excitation current into the excitation winding, so that the electromagnetic force generated by the interaction between the excitation winding and the armature winding can suppress the permanent magnet thrust fluctuation generated by the interaction between the permanent magnet and the armature winding, thereby achieving electromagnetic force fluctuation suppression.

[0151] It should be noted that the electromagnetic force fluctuation suppression device for the hybrid excitation motor provided in the above embodiments is only illustrated by the division of the above functional modules when executing the electromagnetic force fluctuation suppression method for the hybrid excitation motor. In practical applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above. In addition, the electromagnetic force fluctuation suppression device for the hybrid excitation motor provided in the above embodiments and the electromagnetic force fluctuation suppression method embodiments for the hybrid excitation motor belong to the same concept. The implementation process is detailed in the electromagnetic force fluctuation suppression method embodiments for the hybrid excitation motor, and will not be repeated here.

[0152] Figure 6 (a) Figure 6 (b) A structural diagram of a hybrid excitation transverse flux switching linear motor is given. In this embodiment, the motor has 3 phases and 4 poles. There are 6 secondary magnetic conductive components. At the same time, the air gap between the teeth of the primary magnetic conductive component and the secondary magnetic conductive component is constructed as an oblique air gap.

[0153] The following provides a further explanation of the specific structure of the hybrid excitation transverse flux switching linear motor described above.

[0154] like Figure 6 (a) Figure 6 (b) Figure 7 , Figure 8 , Figure 10 As shown, a hybrid excitation transverse flux switching linear motor includes a primary section and a secondary section, with the secondary section arranged within the primary section, allowing relative displacement between them. The primary section is composed of multiple primary units with identical structures arranged side-by-side. Each primary unit includes a primary magnetic guide component 1, an excitation winding 7, an armature winding 3, and a permanent magnet 2. The yoke of the primary magnetic guide component 1 forms a magnetic bridge. The primary magnetic guide component 1 has a U-shaped structure, with multiple protrusions I evenly spaced along the entire circumference on its inner ring surface. Each protrusion I has a permanent magnet 2 forming a magnetic pole, and the armature winding 3 is wound around this magnetic pole. Four grooves are evenly spaced along the entire circumference on the side of the primary magnetic guide component 1, and the excitation winding 7 is wound in the grooves. The secondary section consists of a fixed shaft 6 and multiple secondary magnetic guide components arranged and fixedly mounted on the fixed shaft 6. When a secondary magnetic guide component is aligned with a primary unit, multiple air gaps exist between them.

[0155] In a three-phase motor, primary units of different phases are spaced 120° electrical degrees apart to form the motor phases. The number of primary units and secondary magnetic materials is not limited to this and can be increased or decreased according to the actual situation such as the number of motor phases and length. The windings of primary units in the same phase are connected in series or parallel. The number of primary units is an integer multiple of the number of motor phases. The air gap structure between the teeth of the primary and secondary magnetic components includes, but is not limited to, oblique air gap structures or arc-shaped air gap structures. Linear motors can function as both generators and motors.

[0156] It should be noted that, as Figure 8 As shown, the four protruding teeth I of the primary magnetic conductive component 1 and the four permanent magnets 2 are arranged in a uniform alternating pattern along the circumference to form four magnetic poles; as Figure 6 As shown in (a), the four excitation windings 7 are respectively wound around the iron core between two adjacent grooves of the primary magnetic conductor 1; as Figure 6 As shown in (b), the excitation winding 7 is wound in four grooves in a loop structure.

[0157] like Figure 7 , Figure 9 , Figure 10As shown, multiple secondary magnetic conductive components are formed by alternating secondary magnetic conductive components I4 and II5, which are mirror images of each other, causing the magnetic flux of the motor windings to change during motor operation. Both secondary magnetic conductive components I4 and II5 have four protruding teeth II, with one protruding tooth II corresponding to one protruding tooth I. An air gap is formed between the protruding teeth I and II, resulting in four circumferentially evenly distributed oblique air gaps between the primary unit and the secondary magnetic conductive components. When secondary magnetic conductive component I4 is aligned with the primary unit, secondary magnetic conductive component II5 cannot be aligned with the primary unit; when secondary magnetic conductive component II5 is aligned with the primary unit, secondary magnetic conductive component I4 cannot be aligned with the primary unit. The positions of the four oblique air gaps formed when secondary magnetic conductive component I4 is aligned with the primary unit are different from the positions of the four oblique air gaps formed when secondary magnetic conductive component II5 is aligned with the primary unit.

[0158] Further plans will continue to be considered. Figure 7 As shown, the magnetization directions of adjacent permanent magnets in the motor's motion direction are consistent. Furthermore, there are four circumferentially distributed oblique air gaps between the primary and secondary magnetic guiding components. These four oblique air gaps are denoted as air gap A, air gap B, air gap C, and air gap D, respectively. It can be seen that air gaps A and C are parallel and centrally symmetrically distributed, as are air gaps B and D. When the primary unit interacts with the secondary magnetic guiding component, the forces in the two pairs of air gaps formed by air gaps A and C, and air gaps B and D, pass through the center of the circle and are in opposite directions. This can eliminate the tangential torque during motor operation, reduce the difficulty of motor fixing, and extend the motor's service life.

[0159] It should be noted that the fixed shaft 6 is made of non-magnetic material, and the primary magnetic component 1 and the secondary magnetic components 4 and 5 are all made of stacked iron core silicon steel sheets.

[0160] Working Principle: The permanent magnet and the excitation winding are connected in parallel, and the magnetic fields they generate are superimposed in the motor's magnetic circuit. When the primary unit aligns with different secondary magnetic conductive components, the permanent magnet and the excitation winding generate magnetic flux linkages in different directions within the windings. Therefore, when the motor's secondary winding moves along the direction of motion (i.e., the primary and secondary parts undergo relative displacement), the primary unit alternately aligns with different secondary magnetic conductive components. That is, the protrusions of the secondary part align with the protrusions of the primary unit, causing the magnetic flux linkages through the windings on the primary magnetic poles to change alternately. This induces a corresponding electromotive force in the armature windings, and when a changing current is applied to the windings, a thrust is generated. By rationally arranging the spacing between the primary units and the secondary magnetic conductive components, and based on the relative positions between the primary and secondary windings in the direction of motion, and rationally energizing each phase winding of the primary unit, a continuous thrust can be generated. By changing the magnitude and direction of the excitation current, the magnetic field can be adjusted, enabling the motor to achieve magnetization starting, field weakening speed regulation, voltage regulation during generator operation, and fault protection.

[0161] Figure 11 (a) is a schematic diagram of the magnetic flux flow direction when the secondary magnetic conductor I4 is aligned with the primary unit in the magnetization state of a hybrid excitation transverse magnetic flux switching linear motor proposed in this invention. Figure 11 (b) is a schematic diagram of the magnetic flux flow direction when the secondary magnetic conductor II5 is aligned with the primary unit in the magnetization state of a hybrid excitation transverse flux switching linear motor proposed in this invention. From Figure 11 It can be seen that when the excitation current is in the direction shown in the figure, the excitation flux loop and the permanent magnet flux loop are connected in parallel, and the flux direction is consistent at the alignment position of the primary magnetic guide component teeth and the secondary magnetic guide component teeth, which effectively improves the air gap magnetic flux density, indicating that the hybrid excitation structure can effectively enhance the magnetic field. When the secondary moves, from the alignment of the secondary magnetic guide component I4 with the primary unit to the alignment of the secondary magnetic guide component II5 with the primary unit, the direction of the armature winding flux linkage and the direction of the internal magnetic flux flow of the motor both change, indicating that the principle of the motor is feasible and the structure is reliable.

[0162] Figure 12 (a) is a schematic diagram of the magnetic flux flow direction when the secondary magnetic conductor I4 is aligned with the primary unit in the demagnetized state of a hybrid excitation transverse magnetic flux switching linear motor proposed in this invention. Figure 12 (b) is a schematic diagram of the magnetic flux flow direction when the secondary magnetic conductor II5 is aligned with the primary unit in the demagnetized state of the hybrid excitation transverse flux switching linear motor proposed in this invention. From Figure 7 It can be seen that when the excitation current is in the direction shown in the figure, the excitation flux circuit and the permanent magnet flux circuit are connected in parallel, and the flux directions are opposite at the alignment positions of the primary magnetic guide component teeth and the secondary magnetic guide component teeth, which effectively reduces the air gap magnetic flux density, indicating that the hybrid excitation structure can effectively weaken the magnetic field. When the secondary moves, from the alignment of the secondary magnetic guide component I4 with the primary unit to the alignment of the secondary magnetic guide component II5 with the primary unit, the direction of the armature winding flux linkage and the direction of the internal magnetic flux flow of the motor both change, indicating that the principle of the motor is feasible and the structure is reliable.

[0163] Numerous specific details are set forth in the specification provided herein. However, it will be understood that embodiments of the invention may be practiced without these specific details. In some instances, well-known methods, structures, and techniques have not been shown in detail so as not to obscure the understanding of this specification.

[0164] Furthermore, those skilled in the art will understand that although some embodiments described herein include certain features found in other embodiments but not others, combinations of features from different embodiments are also within the scope of protection of this invention and form different embodiments. For example, in the embodiments described above, those skilled in the art can use them in combination based on known technical solutions and the technical problems to be solved by this application.

[0165] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-described technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A method for suppressing electromagnetic force fluctuations in a hybrid excitation motor, characterized in that, The hybrid excitation motor is a hybrid excitation linear motor or a hybrid excitation rotary motor, and the method includes: A mathematical decoupling model of electromagnetic force for a hybrid excitation motor is constructed using the magnetic co-energy method and Fourier decomposition method. The variables in the mathematical decoupling model of electromagnetic force for the hybrid excitation motor include the magnetomotive force and the rate of change of magnetic permeability of the magnetic source. The magnetic source includes a permanent magnet, an armature winding, and an excitation winding. The self-inductance and mutual inductance of each magnetic source are calculated as a function of mover displacement or rotor rotation. The curves are differentiated and harmonic analyzed to extract the characteristic quantity of the rate of change of mutual inductance of each magnetic source. The mutual inductance of each magnetic source includes: the mutual inductance of permanent magnet and armature winding, and the mutual inductance of excitation winding and armature winding. Substituting the characteristic quantity of the mutual inductance rate of change of permanent magnet and armature winding into the mathematical decoupling model of electromagnetic force of hybrid excitation motor, the characteristic quantity of permanent magnet thrust fluctuation is obtained; the characteristic quantity of permanent magnet thrust fluctuation includes the amplitude, frequency and phase of the fundamental wave and each harmonic. Define the expression for the single-phase excitation current injected into the excitation winding and the corresponding expression for the magnetomotive force of the excitation winding. Substituting the defined characteristic quantities of the magnetomotive force of the excitation winding and the rate of change of mutual inductance of the excitation winding and the armature winding into the mathematical decoupling model of electromagnetic force of the hybrid excitation motor, we can obtain the characteristic quantities of electromagnetic force generated by the interaction of excitation current and armature current. With the optimization objective of minimizing the amplitude of the single-phase excitation current and maximizing the suppression of permanent magnet thrust fluctuations, the single-phase excitation current injected into the excitation winding is solved. Injecting a single-phase excitation current into the excitation winding allows the electromagnetic force generated by the interaction between the excitation winding and the armature winding to suppress the permanent magnet thrust fluctuations generated by the interaction between the permanent magnet and the armature winding, thus achieving electromagnetic force fluctuation suppression.

2. The method for suppressing electromagnetic force fluctuations in a hybrid excitation motor according to claim 1, characterized in that, The expression for the rate of change of mutual inductance between the permanent magnet and the armature winding is: ， Among them, A PAn δ is the amplitude of the nth harmonic of the mutual inductance of the permanent magnet and the armature winding, w is the angular frequency of the motor, v is the speed of the motor mover, δ is the fundamental phase angle of the rate of change of mutual inductance of the permanent magnet and the armature winding A phase, and x represents the distance of the motor mover displacement or the angle of the rotor rotation.

3. The method for suppressing electromagnetic force fluctuations in a hybrid excitation motor according to claim 2, characterized in that, The average thrust component is removed from the mathematical expression of the permanent magnet thrust characteristic quantity to obtain the permanent magnet thrust fluctuation characteristic quantity. The mathematical expression of the permanent magnet thrust characteristic quantity is as follows: ， in, F is the characteristic quantity of permanent magnet thrust. a F b and F c These are the magnetomotive forces of the three-phase armature windings, F P Λ represents the magnetomotive force of a permanent magnet. Pa Λ Pb and Λ Pc These are the mutual inductance of the permanent magnet and the three-phase armature winding, respectively. When the rate of change of mutual inductance is the amplitude of the 5th and 7th harmonics, the expression for the characteristic quantity of permanent magnet thrust fluctuation is as follows: ， Among them, A PA5 and A PA7 These are the 5th and 7th harmonic amplitudes of the rate of change of mutual inductance of the permanent magnet and the armature winding, respectively. This represents the amplitude of the armature winding magnetomotive force.

4. The method for suppressing electromagnetic force fluctuations in a hybrid excitation motor according to claim 3, characterized in that, The expression for single-phase excitation current is defined as follows: ， Among them, i F For the excitation current, I F φ is the amplitude of the excitation current, t is the ratio of the excitation current frequency to the armature current frequency, and φ is the phase of the excitation current. The expression for the magnetomotive force of the excitation winding is defined as follows: ， Where, N F F is the number of turns in the excitation winding. f This represents the amplitude of the excitation magnetomotive force.

5. The method for suppressing electromagnetic force fluctuations in a hybrid excitation motor according to claim 1 or 4, characterized in that, The characteristic quantity of the rate of change of mutual inductance of the excitation winding and the armature winding is: ， Among them, A FAn δ is the amplitude of the nth harmonic of the mutual inductance of the excitation winding and the armature winding, w is the angular frequency of the motor, v is the speed of the motor mover, δ is the fundamental phase angle of the rate of change of mutual inductance of the permanent magnet and the armature winding A phase, and x represents the distance of the motor mover displacement or the angle of the rotor rotation. When the rate of change of mutual inductance is the amplitude of the 5th and 7th harmonics, the expression for the characteristic quantity of the electromagnetic force generated by the interaction of the excitation current and armature current is: ， in, The fundamental amplitude of the rate of change of mutual inductance permeability. This represents the amplitude of the armature winding magnetomotive force. This represents the magnetomotive force amplitude of the excitation winding.

6. An electromagnetic force fluctuation suppression device for a hybrid excitation motor, characterized in that, The device includes: a hybrid excitation motor electromagnetic force mathematical decoupling model module, used to construct a hybrid excitation motor electromagnetic force mathematical decoupling model using the magnetic co-energy method and Fourier decomposition method; the variables of the hybrid excitation motor electromagnetic force mathematical decoupling model include the magnetomotive force and the rate of change of magnetic permeability of the magnetic source; the magnetic source includes a permanent magnet, an armature winding and an excitation winding; The characteristic quantity extraction module for the rate of change of magnetic permeability is used to calculate the curves of the self-inductance and mutual inductance of each magnetic source as a function of the mover displacement or the rotor rotation, and to perform differentiation and harmonic analysis on the curves to extract the characteristic quantity of the rate of change of mutual inductance of each magnetic source; the mutual inductance of each magnetic source includes: the mutual inductance of the permanent magnet and the armature winding, and the mutual inductance of the excitation winding and the armature winding. The permanent magnet thrust fluctuation characteristic quantity calculation module is used to substitute the characteristic quantity of the mutual inductance permeability change rate between the permanent magnet and the armature winding into the electromagnetic force mathematical decoupling model of the hybrid excitation motor to obtain the permanent magnet thrust fluctuation characteristic quantity; the permanent magnet thrust fluctuation characteristic quantity includes the amplitude, frequency and phase of the fundamental wave and each harmonic. The definition module is used to define the expression for the single-phase excitation current injected into the excitation winding and the corresponding magnetomotive force expression of the excitation winding. The electromagnetic force characteristic quantity calculation module is used to substitute the defined characteristic quantities of the magnetomotive force of the excitation winding and the rate of change of mutual inductance of the excitation winding and the armature winding into the electromagnetic force mathematical decoupling model of the hybrid excitation motor to obtain the electromagnetic force characteristic quantity generated by the interaction of the excitation current and the armature current. The optimization module is used to solve for the single-phase excitation current injected into the excitation winding with the optimization objectives of minimizing the excitation current amplitude and maximizing the suppression of permanent magnet thrust fluctuations. The single-phase excitation current injection module is used to inject single-phase excitation current into the excitation winding, so that the electromagnetic force generated by the interaction between the excitation winding and the armature winding can suppress the permanent magnet thrust fluctuation generated by the interaction between the permanent magnet and the armature winding, thereby achieving electromagnetic force fluctuation suppression.

7. A hybrid-excitation transverse flux-switching linear motor, wherein electromagnetic force fluctuation suppression is performed using the electromagnetic force fluctuation suppression method of the hybrid-excitation motor according to any one of claims 1-5, characterized in that, The hybrid excitation transverse flux switching linear motor includes a primary part and a secondary part, wherein the secondary part is arranged in the primary part and the two parts are capable of relative displacement. The primary section is composed of multiple primary units with the same structure arranged side by side in a uniform manner. The primary unit includes a primary magnetic conductor, an excitation winding, an armature winding, and a permanent magnet. The yoke of the primary magnetic conductor forms a magnetic bridge. The primary magnetic conductive component has a U-shaped structure, with four protruding teeth I evenly spaced along the entire circumference on its inner ring surface. Each protruding tooth I is equipped with a permanent magnet to form a magnetic pole, and the armature winding is wound around the magnetic pole. The primary magnetic conductive component has four grooves evenly spaced along the entire circumference on its side surface, and the excitation winding is wound in the grooves. The secondary part consists of a fixed shaft and a plurality of secondary magnetic conductive components arranged and fixed on the fixed shaft in sequence; when a secondary magnetic conductive component is aligned with a primary unit, there will be a plurality of air gaps between them.

8. A hybrid excitation transverse flux switching linear motor according to claim 7, characterized in that: The plurality of secondary magnetic conductive components are formed by alternating two types of secondary magnetic conductive components I and secondary magnetic conductive components II, which are mirror images of each other; Both the secondary magnetic conductive component I and the secondary magnetic conductive component II are provided with four protruding teeth II, and one protruding tooth II corresponds to one protruding tooth I. The air gap is formed between the protruding teeth I and the protruding teeth II, and thus there are four oblique air gaps evenly distributed in the circumferential direction between the primary unit and the secondary magnetic conductive component. When the secondary magnetic conductive component I is aligned with the primary unit, the secondary magnetic conductive component II cannot be aligned with the primary unit; when the secondary magnetic conductive component II is aligned with the primary unit, the secondary magnetic conductive component I cannot be aligned with the primary unit; the positions of the four oblique air gaps formed when the secondary magnetic conductive component I is aligned with the primary unit are different from the positions of the four oblique air gaps formed when the secondary magnetic conductive component II is aligned with the primary unit.

9. A hybrid excitation transverse flux switching linear motor according to claim 8, characterized in that: The four oblique air gaps are denoted as air gap A, air gap B, air gap C and air gap D along the circumference. Air gap A and air gap C are parallel and centrally symmetrically distributed, and air gap B and air gap D are parallel and centrally symmetrically distributed. When the primary unit interacts with the secondary magnetic components, the forces in the two pairs of air gaps formed by air gaps A and C, and air gaps B and D, pass through the center of the circle and are in opposite directions, which can eliminate the tangential torque during motor operation.

10. A hybrid excitation transverse flux switching linear motor according to claim 9, characterized in that: When the magnetic flux circuit of the excitation winding is connected in parallel with the magnetic flux circuit of the permanent magnet and the magnetic flux direction is consistent at the alignment position of the tooth I of the primary magnetic guiding component and the tooth II of the secondary magnetic guiding component, the air gap magnetic flux density is improved. When a relative displacement occurs between the secondary part and the primary part, and the alignment of the secondary magnetic guide component I with the primary unit is changed to the alignment of the secondary magnetic guide component II with the primary unit, the permanent magnet and the excitation winding generate magnetic flux in different directions in the winding, and a corresponding induced electromotive force will be induced in the armature winding. When a changing current is applied to the winding, a thrust will be generated.

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