CN110581632A - Permanent magnet vernier motor with non-uniform tooth topology and its magnetic field modulation method - Google Patents

Abstract

The invention provides a permanent magnet vernier motor with non-uniform tooth topology and its magnetic field modulation method. The permanent magnet vernier motor with non-uniform tooth topology is provided with a plurality of tooth units at intervals on the stator ring, and each tooth unit is adjacent to two The spacing between the stator teeth is not equal to the slot pitch of the tooth unit slots formed between two adjacent tooth units, and the multiple stator teeth in each tooth unit are symmetrical about the center plane of the tooth unit, so that the stator ring is formed on the stator ring. The non-uniformly distributed tooth structure introduces the target permeance harmonic of the frequency corresponding to the winding magnetomotive force harmonic that is not utilized by the no-load air gap magnetic density harmonic, and modulates the no-load air gap through the non-uniformly distributed tooth structure and permanent magnets Flux density harmonics, so that the no-load air-gap flux density harmonics correspond to the target permeance harmonics, so that the no-load air-gap flux density harmonics corresponding to the target permeance harmonics are modulated by non-uniformly distributed tooth structures and permanent magnets , make full use of the magnetomotive force harmonics generated by the armature winding, and increase the output torque and torque density of the permanent magnet vernier motor.

Description

Permanent magnet vernier motor with non-uniform tooth topology and its magnetic field modulation method

technical field

The invention belongs to the technical field of permanent magnet motor and permanent magnet motor design, and more specifically relates to a permanent magnet vernier motor with non-uniform tooth topology and a magnetic field modulation method thereof.

Background technique

As a low-speed and high-torque direct-drive motor, Vernier Machine has broad application prospects in new energy fields such as electric vehicles, wind power generation, and wave power generation. The vernier motor is a kind of permanent magnet motor with unequal number of stator and rotor poles. It mainly includes stator, rotor and magnetic field modulation part. The current open-slot permanent magnet vernier motor usually has a plurality of stator slots accommodating the armature winding evenly along the circumference of the stator, and the protruding parts between the stator slots form stator teeth. Magnetic modulation (magnetic field modulation) is carried out, so that the magnetic field of most pole logarithms of the rotor is modulated into a few pole logarithmic magnetic fields matching the stator, thereby generating a stable electromagnetic torque. However, this permanent magnet vernier motor with a uniformly distributed tooth structure will cause a large number of winding magnetomotive force harmonics of the armature winding to be underutilized, which severely limits the improvement of the output torque and torque density of the permanent magnet vernier motor.

Contents of the invention

One of the purposes of the present invention is to provide a permanent magnet vernier motor with non-uniform tooth topology, to solve the problem that the permanent magnet vernier motor in the prior art is difficult to fully utilize the harmonics of the winding magnetomotive force and limit the output torque of the permanent magnet vernier motor And the problem of torque density improvement.

In order to achieve the above object, the technical solution adopted by the present invention is to provide a permanent magnet vernier motor with non-uniform tooth topology, including a stator and a rotor, and the rotor includes a rotor frame and multiple pairs of permanent magnets installed on the rotor frame; The stator includes a stator ring, a plurality of tooth units arranged at equal intervals on the stator ring, and several stator windings, and a tooth unit slot is formed between two adjacent tooth units; each tooth unit includes a plurality of Stator teeth, each of the stator teeth is respectively provided with the stator winding; a plurality of the stator teeth in each of the tooth units are symmetrical with respect to the center plane of the tooth unit, and two adjacent teeth in each of the tooth units The spacing between the stator teeth is not equal to the slot pitch of the tooth unit slots.

Further, the stator winding is a three-phase symmetrical concentrated armature winding.

Further, each of the tooth units includes _{ng stator teeth arranged in sequence, and the number of the tooth units is Z f ,} and the number of the stator teeth on the stator is Z _s , then Wherein, Z _s , Z _f , and n _g are integers greater than 1, respectively.

Further, the tooth widths of the stator teeth of the plurality of tooth units are equal.

Further, the included angles between the central planes of two adjacent tooth units are equal.

The beneficial effect of the non-uniform teeth topology permanent magnet vernier motor provided by the present invention lies in that: compared with the prior art, the non-uniform tooth topology permanent magnet vernier motor provided by the present invention, by arranging multiple Tooth unit, the spacing between two adjacent stator teeth in each tooth unit is not equal to the slot pitch of the tooth unit slots formed between two adjacent tooth units, and the multiple stator teeth in each tooth unit are relative to the teeth The central plane of the unit is symmetrical, so that the stator teeth on the stator form a non-uniform distribution tooth structure, and introduce the target permeance harmonic of the frequency corresponding to the winding magnetomotive force harmonic that is not utilized by the no-load air gap magnetic density harmonic, The no-load air-gap magnetic density harmonics are modulated by the non-uniformly distributed tooth structure and the permanent magnet, so that the no-load air-gap magnetic density harmonics correspond to the target permeance harmonics, and thus the non-uniformly distributed tooth structure and the permanent magnet are modulated to match The no-load air-gap flux density harmonic corresponding to the target flux permeance harmonic fully utilizes the magnetomotive force harmonic generated by the armature winding to realize the additional net output torque of the motor, thereby increasing the output torque and speed of the permanent magnet vernier motor. moment density.

The second object of the present invention is to provide a modulation method for a permanent magnet vernier motor with a non-uniform tooth topology, so as to solve the problem that it is difficult for the permanent magnet vernier motor in the prior art to fully utilize the harmonics of the winding magnetomotive force and limit the output of the permanent magnet vernier motor. The issue of torque and torque density enhancements.

In order to achieve the above object, the technical solution adopted by the present invention is to provide a magnetic field modulation method of a permanent magnet vernier motor with a non-uniform tooth topology, including the introduction of the winding magnetomotive force harmonics that are not utilized by the no-load air gap flux density harmonics The target permeance harmonic of the corresponding frequency is modulated by the target permeance harmonic and the permanent magnet to produce an unloaded air-gap magnetic density harmonic, and the unloaded air-gap magnetic density harmonic and the unloaded The air-gap flux density harmonics correspond to the winding magnetomotive force harmonics.

Further, the magnetic field modulation method of the non-uniform tooth topology permanent magnet vernier motor also includes a step of selecting the winding magnetomotive force harmonic before the step of introducing the target flux permeance harmonic, and the winding magnetomotive force harmonic selection step The steps include: calculating and analyzing the harmonic components of the winding magnetomotive force of the armature winding under the condition that a plurality of the stator teeth are arranged in a ring and uniformly distributed at equal intervals, and selecting the unloaded air gap The flux density harmonics utilize the winding magnetomotive force harmonics.

Further, the magnetic field modulation method of the non-uniform tooth topology permanent magnet vernier motor also includes a cogging torque optimization step before the step of introducing the target permeance harmonic, and the cogging torque optimization step includes: using The cogging torque phasor analyzes the cogging torque harmonics of the stator teeth at the same order position in the plurality of tooth units respectively, by modifying the Tooth width and position to eliminate specific sub-cogging torque harmonics.

Further, after the cogging torque optimization step, by calculating the target permeance harmonic and the effective sub-order air-gap magnetic density harmonic content modulated by the permanent magnet, when the cogging torque is satisfied Under the condition of the minimum torque, determine the design point with the highest output torque.

Further, the electromagnetic torque calculated according to the content analysis and calculation of the target permeance harmonics and the effective no-load air-gap magnetic density harmonic content modulated by the permanent magnet satisfies the relational expression:

Among them, k _T is the torque coefficient, is the |Z _r ±mZ _f | sub-harmonic amplitude of the magnetic density corresponding to the winding magnetomotive force, T _e is the electromagnetic torque, B _effect is the effective magnetic density of the air gap, Z _r is the number of pole pairs of the permanent magnet, and Z _f is The number of tooth units, m is a natural number.

The beneficial effect of the magnetic field modulation method of a non-uniform tooth topology permanent magnet vernier motor provided by the present invention is that: compared with the prior art, the non-uniform tooth topology permanent magnet vernier motor magnetic field modulation method provided by the present invention, through the stator A plurality of tooth units are arranged at intervals on the ring, and the distance between two adjacent stator teeth in each tooth unit is not equal to the slot pitch of the tooth unit slots formed between two adjacent tooth units, and the number of teeth in each tooth unit The three stator teeth are symmetrical about the central plane of the tooth unit, so that the stator teeth on the stator ring form a non-uniformly distributed tooth structure to ensure the three-phase symmetry of the stator tooth winding. The non-uniformly distributed tooth structure on the stator can be used to introduce the target permeance harmonic of the frequency corresponding to the winding magnetomotive force harmonic that is not utilized by the no-load air gap magnetic density harmonic, and the non-uniformly distributed tooth structure and permanent magnet Modulate the no-load air-gap magnetic density harmonics, so that the no-load air-gap magnetic density harmonics correspond to the target permeance harmonics, so that the no-load corresponding to the target permeance harmonics is modulated by non-uniformly distributed tooth structure and permanent magnets Air-gap flux density harmonics make full use of the magnetomotive force harmonics generated by the armature windings to realize additional net output torque of the motor, thereby increasing the output torque and torque density of the permanent magnet vernier motor.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the accompanying drawings that need to be used in the descriptions of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only of the present invention. For some embodiments, those of ordinary skill in the art can also obtain other drawings based on these drawings without paying creative efforts.

Fig. 1 is the three-dimensional schematic diagram of the permanent magnet vernier motor with non-uniform tooth topology provided by the embodiment of the present invention;

Fig. 2 is a three-dimensional schematic diagram of a stator winding provided on a stator of a permanent magnet vernier motor with a non-uniform tooth topology provided by an embodiment of the present invention;

FIG. 3 is a schematic diagram of the three-dimensional structure of the stator of the non-uniform tooth topology permanent magnet vernier motor provided by the embodiment of the present invention;

Fig. 4 is a top view structural diagram of a permanent magnet vernier motor with a non-uniform tooth topology provided by an embodiment of the present invention with a stator winding wound on the stator;

Fig. 5 is a schematic structural diagram of the stator tooth division tooth unit in the magnetic field modulation method of the non-uniform tooth topology permanent magnet vernier motor provided by the embodiment of the present invention;

Fig. 6 is a schematic structural diagram of cogging torque grouping in the magnetic field modulation method of a permanent magnet vernier motor with a non-uniform tooth topology provided by an embodiment of the present invention;

7 is a schematic diagram of cogging torque grouping in the magnetic field modulation method of a permanent magnet vernier motor with a non-uniform tooth topology provided by an embodiment of the present invention;

Fig. 8 is a schematic structural diagram of the short-distance distributed winding of the stator winding in the magnetic field modulation method of the non-uniform tooth topology permanent magnet vernier motor provided by the embodiment of the present invention;

9 is a phasor diagram of each group of cogging torque in the magnetic field modulation method of a permanent magnet vernier motor with a non-uniform tooth topology provided by an embodiment of the present invention;

Fig. 10 is a cogging torque subharmonic phasor diagram when n _g = 4 in the magnetic field modulation method of a permanent magnet vernier motor with a non-uniform tooth topology provided by an embodiment of the present invention;

Fig. 11 is a schematic structural view of each tooth unit on the stator provided by the embodiment of the present invention including four evenly distributed stator teeth;

Fig. 12 is a schematic structural view of each tooth unit on the stator provided by an embodiment of the present invention including four non-uniformly distributed stator teeth.

Wherein, each accompanying drawing in the figure mainly marks: .

1-stator; 11-stator ring; 12-tooth unit; 121-stator tooth; 13-stator winding;

2-rotor; 21-rotor frame; 22-permanent magnet;

3-center plane; 4-tooth unit groove.

Detailed ways

In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention clearer, the present invention is preferably described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention.

It should be noted that when an element is referred to as being “fixed” or “disposed on” another element, it may be directly on the other element or be indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be interpreted as indicating or implying relative importance or implicitly specifying the quantity of indicated technical features. Thus, a feature defined as "first" and "second" may explicitly or implicitly include one or more of these features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined. "Several" means one or more than one, unless otherwise clearly and specifically defined.

In the description of the present invention, it should be noted that unless otherwise specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection. Connection, or integral connection; it may be mechanical connection or electrical connection; it may be direct connection or indirect connection through an intermediary, and it may be the internal communication of two elements or the interaction relationship between two elements. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present invention according to specific situations.

Referring to FIG. 1 to FIG. 3 , a permanent magnet vernier motor with a non-uniform tooth topology provided by the present invention will now be described. A permanent magnet vernier motor with non-uniform teeth topology provided by the present invention includes a stator 1 and a rotor 2, the rotor 2 includes a rotor frame 21 and multiple pairs of permanent magnets 22 installed on the rotor frame 21; the stator 1 includes a stator ring 11, A plurality of tooth units 12 and a plurality of stator windings 13 arranged at equal intervals on the stator ring 11, a tooth unit slot 4 is formed between two adjacent tooth units 12; each tooth unit 12 includes a plurality of stator teeth 121, and each stator tooth 121 are respectively provided with stator windings 13; a plurality of stator teeth 121 in each tooth unit 12 are symmetrical with respect to the central plane 3 of the tooth unit 12, and the distance between two adjacent stator teeth 121 in each tooth unit 12 is the same as that of the teeth The slot pitches of the unit slots 4 are not equal, so that the stator teeth 121 on the stator 1 form a non-uniformly distributed tooth structure. Moreover, each tooth unit 12 corresponds to an arc segment on the stator ring 11 , and the central symmetry plane of the arc segment is the central plane 3 of the tooth unit 12 .

Specifically, the plurality of stator teeth 121 in each tooth unit 12 are symmetrical to the central plane 3 of the tooth unit 12, that is, each tooth unit 12 may contain two or more stator teeth 121, and each tooth unit 12 contains two stator teeth 121. One or more stator teeth 121 are symmetrical to the central plane 3 of the tooth unit 12 . And, as shown in FIG. 11 and FIG. 12 , when each tooth unit 12 includes four or more stator teeth 121, a plurality of stator teeth 121 in each tooth unit 12 satisfy the requirements on the central plane of the tooth unit 12. 3 Under the condition of symmetry, the multiple stator teeth 121 in each tooth unit 12 can be uniformly distributed or non-uniformly distributed. When the multiple stator teeth 121 in each tooth unit 12 are unevenly distributed, the The target permeance harmonic of the frequency corresponding to the winding magnetomotive force harmonic used by the carrier air gap flux density harmonic is modulated by the non-uniformly distributed tooth structure and the permanent magnet 22 to produce the no-load air-gap flux density harmonic, so that the no-load air gap The flux density harmonics correspond to the target flux density harmonics, and then the no-load air gap flux density harmonics corresponding to the target flux density harmonics are modulated by the non-uniformly distributed tooth structure and the permanent magnet 22, making full use of the magnetic flux generated by the armature winding. Motive force harmonics can realize additional net output torque of the motor and increase the output torque and torque density of the permanent magnet vernier motor.

The non-uniform tooth topology permanent magnet vernier motor provided by the present invention, compared with the prior art, by arranging a plurality of tooth units 12 at intervals on the stator ring 11, the teeth between two adjacent stator teeth 121 in each tooth unit 12 The pitch is not equal to the slot pitch of the tooth unit slots 4 formed between two adjacent tooth units 12, and a plurality of stator teeth 121 in each tooth unit 12 are symmetrical about the central plane 3 of the tooth unit 12, so that the stator 1 The stator teeth 121 on the top form a non-uniform distribution tooth structure, which introduces the target permeance harmonic of the frequency corresponding to the winding magnetomotive force harmonic that is not utilized by the no-load air gap magnetic density harmonic, and through the non-uniform distribution tooth structure and the permanent magnet 22 modulates the no-load air-gap magnetic density harmonic, so that the no-load air-gap magnetic density harmonic corresponds to the target permeance harmonic, and then modulates the target permeance harmonic through the non-uniformly distributed tooth structure and permanent magnet 22 No-load air-gap magnetic density harmonics make full use of the magnetomotive force harmonics generated by the armature winding to realize additional net output torque of the motor and increase the output torque and torque density of the permanent magnet vernier motor.

Preferably, as a specific implementation of the non-uniform tooth topology permanent magnet vernier motor provided by the present invention, the stator winding 13 is a three-phase symmetrical centralized armature winding, which ensures that the three-phase winding is symmetrical after the stator teeth 121 are non-uniformly distributed. , The cogging torque does not increase sharply, thereby reducing the cogging torque fluctuation and improving the stability of the permanent magnet vernier motor.

Specifically, take the analysis of the harmonic components of the magnetomotive force of the three-phase armature winding as an example to illustrate: due to the special ratio of poles of the open slot vernier motor, there is a large gap between the number of pole pairs of the armature winding and the number of stator teeth 121. A winding scheme of distributed and concentrated winding is formed, and the number of pole pairs p of the armature winding of the vernier motor is often low (p≤3). As shown in Figure 8, the stator winding 13 includes A-phase sub-windings, B-phase sub-windings and C-phase sub-windings, wherein the A-phase sub-windings, B-phase sub-windings and C-phase sub-windings are respectively divided into p groups, each phase The group includes Zs/3/p stator teeth 121, on which Zs/3/p stator teeth 121 are wound in the same direction, and are symmetrically distributed around the stator ring 11 at an interval of 360/p angles, thereby producing the effect of p pairs of poles . Using this method, the even-order harmonics of the winding magnetomotive force generated by the poles cannot cancel each other out, so there are even-order harmonic components in the winding magnetomotive force in the following formula (1-1).

When the three-phase symmetrical centralized armature winding is fed with a symmetrical three-phase current i=I sin(ωt-α), the harmonic components of the magnetomotive force of the three-phase centralized double-layer armature winding satisfy the following relationship:

Among them, p is the number of pole pairs of the winding, ω is the angular velocity of the winding input three-phase current, α is the initial phase angle of the current, k _w is the winding factor of each harmonic, F _c1 is the Fourier decomposition fundamental wave content, θ _m is Rotor 2 mechanical position angle, n is a natural number that takes values from small to large.

Further, please refer to Fig. 2 and Fig. 3, as a specific embodiment of the non-uniform tooth topology permanent magnet vernier motor provided by the present invention, each tooth unit 12 includes n _g units arranged in sequence on the stator ring 11 , and the number of tooth units 12 is Z _f , and the number of stator teeth 121 on the stator ring 11 is Z _s , then Wherein, Z _s , Z _f , and n _g are integers greater than 1, respectively.

Specifically, referring to Fig. 2, Fig. 3 and Fig. 5, the Z _s stator teeth 121 are arranged in a ring shape and at intervals on the stator ring 11, and n _g successively arranged ones are sequentially selected clockwise or counterclockwise The stator tooth 121 is a tooth unit 12, so that Z _s stator teeth 121 are divided into Z _f tooth units 12, so that Z _f tooth units 12 and Z _s stator teeth 121 satisfy the relational expression In order to ensure that the additional permeance harmonic content corresponding to the frequency of the low-order winding magnetomotive force harmonic that is not utilized by the no-load air gap flux density harmonic can be introduced by adjusting the spacing between adjacent stator teeth 121, it is necessary to ensure that each The number n _g of the stator teeth 121 of the tooth unit 12 is greater than one.

Further, referring to Fig. 2 and Fig. 3, as a specific embodiment of the non-uniform tooth topology permanent magnet vernier motor provided by the present invention, a plurality of tooth units 12 have the same distribution structure of stator teeth 121, so that the stator teeth 121 wound around The plurality of centralized armature windings on the Z _s stator teeth 121 are symmetrical between phases, which ensures that the three-phase windings are symmetrical after the stator teeth 121 are unevenly distributed, and the cogging torque does not increase sharply, thereby reducing the cogging torque Fluctuation, improve the stability of permanent magnet vernier motor operation.

Further, referring to Fig. 2 and Fig. 3, as a specific embodiment of the non-uniform tooth topology permanent magnet vernier motor provided by the present invention, the tooth widths of the stator teeth 121 of the plurality of tooth units 12 are equal to eliminate Z _s The teeth jointly generate a specific subharmonic of the cogging torque, which ensures that the cogging torque does not increase sharply after the stator teeth 121 are unevenly distributed, thereby reducing cogging torque fluctuations and improving the operation stability of the permanent magnet vernier motor.

Further, please refer to Fig. 2 and Fig. 3, as a specific embodiment of the non-uniform tooth topology permanent magnet vernier motor provided by the present invention, the included angles between the central planes 3 of any two adjacent tooth units 12 are equal , that is, the spacing between any two adjacent tooth units 12 is equal, and Z _f tooth units 12 and Z _s stator teeth 121 respectively satisfy the armature winding symmetry condition. According to the total number of stator teeth 121 Z _s , when the three-phase armature winding is symmetrical, the condition to be satisfied when the Z _s stator teeth 121 are unevenly distributed is to ensure that the A-phase sub-winding, B-phase sub-winding and C-phase sub-winding are three The armature windings of the phase winding method are 120° mechanically different from each other. Under the condition of other symmetrical armature windings, the analysis principle of the harmonic components of the magnetomotive force of the three-phase armature windings is the same.

In this embodiment, under the condition that the included angles between the central planes 3 of any two adjacent tooth units 12 are equal and the positions of the central planes 3 of each tooth unit 12 remain unchanged, according to the magnetic The winding magnetomotive force harmonics utilized by dense harmonics adjust the positions of n _g stator teeth 121 in each tooth unit 12 until the distance between two adjacent stator teeth 121 in each tooth unit 12 is the same as that between two adjacent teeth The spacing between the units 12 is not equal, so that the Z _s stator teeth 121 form a non-uniformly distributed tooth structure on the stator ring 11, then the non-uniformly distributed tooth structure on the stator ring 11 can be used to introduce and uniformly distribute on the stator teeth 121 Under the distributed condition, the target permeance harmonic of the frequency corresponding to the winding magnetomotive force harmonic that is not utilized by the no-load air gap magnetic density harmonic is modulated by the non-uniformly distributed tooth structure and the permanent magnet 22 to produce the corresponding permeance harmonic of the target No-load air-gap flux density harmonics make full use of the magnetomotive force harmonics generated by the armature windings to realize the additional net output torque of the motor, thereby increasing the output torque and torque density of the permanent magnet vernier motor.

The present invention also provides a magnetic field modulation method for a permanent magnet vernier motor with a non-uniform tooth topology, including introducing a target permeance harmonic with a frequency corresponding to the winding magnetomotive force harmonic that is not utilized by the no-load air gap magnetic density harmonic , the no-load air-gap flux density harmonic is modulated by the target permeance harmonic and the permanent magnet 22, and the no-load air-gap flux density harmonic corresponds to the winding magnetomotive force harmonic not utilized by the no-load air-gap flux density harmonic .

In this step, the target permeance harmonic of the frequency corresponding to the winding magnetomotive force harmonic that is not utilized by the no-load air gap magnetic density harmonic is introduced through the non-uniformly distributed tooth structure, and is modulated by the target permeance harmonic and the permanent magnet 22 The no-load air-gap flux-density harmonic corresponding to the winding magnetomotive force harmonic not utilized by the no-load air-gap flux-density harmonic is generated, so that the permanent magnet vernier motor increases the output torque and torque density.

Specifically, the magnetic field modulation method of the non-uniform tooth topology permanent magnet vernier motor provided by the present invention includes the following steps:

Step S1: Arranging Z _s stator teeth 121 in a ring at intervals on the stator ring 11 of the stator 1, and sequentially selecting n _g consecutively arranged stator teeth 121 in the clockwise or counterclockwise direction as a tooth unit 12 , so as to divide Z _s stator teeth 121 into Z _f tooth units 12 .

In this step, referring to Fig. 2, Fig. 3 and Fig. 5, the Z _s stator teeth 121 are grouped, and the n _g consecutively arranged stator teeth 121 are divided into a tooth unit 12, so that the Z _f tooth units 12 and Z _s stator teeth 121 satisfy the relation In order to ensure that the additional permeance harmonic content corresponding to the frequency of the low-order winding magnetomotive force harmonic that is not utilized by the no-load air gap flux density harmonic can be introduced by adjusting the spacing between adjacent stator teeth 121, it is necessary to ensure that each The number n _g of the stator teeth 121 of the tooth unit 12 is greater than one.

Step S2: Under the condition that the included angles between the central planes 3 of any two adjacent tooth units 12 are equal and the positions of the central planes 3 of each tooth unit 12 are kept unchanged, according to the harmonics that are not utilized by the no-load air gap magnetic density Winding magnetomotive force harmonics, adjust the positions of n _g stator teeth 121 in each tooth unit 12, until the distance between two adjacent stator teeth 121 in each tooth unit 12 and the distance between two adjacent tooth units 12 The pitches are not equal, so that Z _s stator teeth 121 form a non-uniformly distributed tooth structure on the stator ring 11 .

Specifically, in step S2, according to the working principle of the permanent magnet motor, the torque of the permanent magnet motor comes from the interaction between the flux density of the permanent magnet 22 and the magnetomotive force of the winding at the corresponding times, which can be expressed as:

T＝k _T ∑k _wn F _cn B _PMn (1-2)

Among them, in the formula, B _PMn is the no-load air-gap magnetic density nth harmonic amplitude; k _T is a constant, which is related to the structure of the permanent magnet motor; k _wn is the nth harmonic winding factor; F _cn is the winding magnetomotive force harmonic Amplitude value; n is the number of specific secondary winding magnetomotive force harmonics that are not utilized by no-load air gap magnetic density harmonics.

Step S3: Please refer to FIG. 4, arrange n _g stator teeth 121 in each tooth unit 12 to be symmetrical with respect to the central plane 3 of the tooth unit 12, and set Z _f tooth units 12 to have the same distribution of stator teeth 121 The structure is such that the multiple concentrated armature windings wound on the Z _s stator teeth 121 are symmetrical between phases.

In step S3, since each pair of poles p is wound with the same polarity corresponding to the teeth, the size of p can be fully modulated within the range of the number of teeth. Taking the three-phase centralized double-layer armature winding as an example, it should be ensured that the teeth unit 12 The number Z _f and the number n _g of the stator teeth 121 of each tooth unit 12 satisfy the following relationship:

Step S4: Introduce the target permeance harmonic of the frequency corresponding to the winding magnetomotive force harmonic that is not utilized by the no-load air-gap magnetic density harmonic, and modulate the no-load air-gap magnetic density through the non-uniformly distributed tooth structure and the permanent magnet 22 Harmonics, so that the no-load air gap flux density harmonics correspond to the target flux permeance harmonics, so that the permanent magnet vernier motor increases the output torque and torque density.

In step S4, after the stator teeth 121 on the stator ₁ are changed according to the above-mentioned non-uniformly distributed tooth structure design rules, the order of the fundamental wave of the air gap permeance is changed from Z _s to Z _f . When the momentum harmonic is present, the permeance harmonic increases (n _g -1,…,1)Z _f harmonic, the permeance harmonic content is obviously more abundant, and the additionally introduced permeance harmonic content can be Modulation is performed by changing the distribution law of the stator teeth 121 inside the unit.

For example, for a vernier motor with a traditional 1-17-18 (pZ _r -Z _s ) pole ratio ratio, the no-load air-gap magnetic field is mainly the fundamental wave and the 17th harmonic, which are respectively related to the fundamental wave and the 17th harmonic of the winding magnetomotive force The harmonic action produces a net output torque. Generally speaking, the main harmonic of the no-load magnetomotive force generated by the permanent magnet 22 of the permanent magnet synchronous motor is only the Z _r harmonic of the pole logarithm of the permanent magnet 22 . Through the magnetic field modulation effect, the vernier motor introduces additional Z _s -Z _p harmonics compared with the permanent magnet synchronous motor, but compared with the harmonic content of the winding magnetomotive force, the used winding magnetomotive force is only 1st and 17th. Relatively rich 5th, 7th, 11th, 13th and other low-order winding magnetomotive force harmonics have not been effectively utilized. In this step, the low-order winding magnetomotive force harmonics that are not used by the no-load air gap magnetic density harmonics can be selected according to the winding magnetic dynamic harmonic component relationship in formula (1-1), so as to use the higher amplitude The low-order winding magnetomotive force harmonics interact with the modulated corresponding air-gap magnetic density harmonics, so that the motor rotor 22 additionally generates higher output torque.

Compared with the prior art, the magnetic field modulation method of the non-uniform tooth topology permanent magnet vernier motor provided by the present invention, by arranging a plurality of tooth units 12 at intervals on the stator ring 11, two adjacent stator teeth in each tooth unit 12 The spacing between 121 is not equal to the slot pitch of the tooth unit slot 4 formed between two adjacent tooth units 12, and a plurality of stator teeth 121 in each tooth unit 12 are symmetrical with respect to the central plane 3 of the tooth unit 12, To make the stator teeth 121 on the stator 1 form a non-uniformly distributed tooth structure, introduce the target permeance harmonic of the frequency corresponding to the winding magnetomotive force harmonic that is not utilized by the no-load air-gap magnetic density harmonic, and pass through the non-uniformly distributed tooth structure. The structure and the permanent magnet 22 modulate the no-load air-gap magnetic density harmonic, so that the no-load air-gap magnetic density harmonic corresponds to the target magnetic permeance harmonic, and then through the non-uniform distribution tooth structure and the permanent magnet 22 modulate the harmonic of the target magnetic permeance Harmonics correspond to no-load air-gap flux density harmonics, making full use of the magnetomotive force harmonics generated by the armature windings to realize additional net output torque of the motor and increase the output torque and torque density of the permanent magnet vernier motor.

Preferably, please refer to Fig. 3 and Fig. 4, as a specific implementation of the magnetic field modulation method of the non-uniform tooth topology permanent magnet vernier motor provided by the present invention, the magnetic field modulation method of the non-uniform tooth topology permanent magnet vernier motor is also Including the step of selecting the harmonics of the winding magnetomotive force before the step of introducing the target permeance harmonics, the step of selecting the harmonics of the winding magnetomotive force includes: setting under the condition that a plurality of stator teeth 121 are arranged in a ring and are evenly spaced , calculate and analyze the harmonic components of the winding magnetomotive force of the armature winding, and select the harmonics of the winding magnetomotive force that are not utilized by the no-load air gap flux density harmonics.

In this step, assuming that the Z _s stator teeth 121 are arranged in a ring and evenly distributed at equal intervals, according to the magnetic field modulation principle of the permanent magnet vernier motor, the formula (1-1) is used to calculate and analyze the centralized armature winding Winding magnetomotive force harmonic components, select winding magnetomotive force harmonics that are not utilized by no-load air gap flux density harmonics.

Preferably, as a specific implementation of the magnetic field modulation method of the permanent magnet vernier motor with non-uniform tooth topology structure provided by the present invention, in the step of selecting the harmonics of the winding magnetomotive force, select the components of the harmonic components of the winding magnetomotive force that are not empty The lowest or low-order winding magnetomotive force harmonics with higher amplitudes are used by the air-gap magnetic density harmonics to use the lowest magnetomotive force harmonics with the highest amplitude or higher amplitude magnetomotive force harmonics and The introduced harmonic action corresponding to the sub-air gap magnetic density makes the motor rotor 22 additionally generate higher output torque, further increasing the output torque and torque density of the permanent magnet vernier motor.

Preferably, as a specific implementation of the magnetic field modulation method of the non-uniform tooth topology permanent magnet vernier motor provided by the present invention, the order of the winding magnetomotive force harmonic that is not utilized by the no-load air gap flux density harmonic will be selected denoted as Z _c , and the permeance order of the target permeance harmonic is denoted as Z _fn , then Z _fn = Z _r -Z _c , and the number of 12 tooth units Z _f satisfies the relation Z _f =GCD(Z _fn , Z _s ) or Z _f =Z _s -Z _fn ; wherein, GCD is the greatest common divisor.

In this step, a permanent magnet vernier motor with symmetrical three-phase armature windings with 2p winding magnetomotive force harmonics is taken as an example. Since Z _s is a multiple of 3p, Z _s -3p is also a multiple of 3p. By The number Z _f of 12 tooth units determined by the greatest common divisor must satisfy the symmetry condition of the armature winding.

Specifically, the no-load air-gap flux density harmonic component modulated by the target permeance harmonic and the permanent magnet 22 satisfies the following relationship:

Among them, B is the magnetic density, P is the magnetic permeability, F is the magnetomotive force of the permanent magnet, is |nZ _r ±mZ _f |sub-harmonic amplitude of magnetic density, θ _m is the rotor mechanical position angle; Z _r is the number of permanent magnet pole pairs; Z _f is the number of tooth units; θ is the distance from different positions on the rotor to the reference point angle; m is a natural number, n is an odd number not less than 1.

In this step, according to the formula (1-4), for example, in the evenly distributed tooth structure of the stator teeth 121, the no-load air-gap flux density generated by the permanent magnet 22 mainly has 2(p) and 16(Z _r ) harmonics, The corresponding harmonics of the armature winding magnetomotive force have been utilized, while the remaining low-order harmonics in the formula (1-1), such as 4(2p), 8(4p), have not been utilized. This design method is to choose the lowest harmonic that is not used, that is, 4(2p) times in this example. When wanting to generate 4(2p) times of magnetic density, the required number of permeance Z _fn can be determined by formula (1-4), Z _fn = Z _r (16)-2p(4) = 12, that is, an additional 12 ( Z _fn ) permeance harmonic.

Preferably, as a specific embodiment of the magnetic field modulation method of the permanent magnet vernier motor with the non-uniform tooth topology provided by the present invention, the magnetic field modulation method of the permanent magnet vernier motor with the non-uniform tooth topology also includes the use of non-uniform teeth on the stator 1 The step of optimizing the cogging torque before the step of introducing the target permeance harmonic evenly distributed tooth structure, the step of optimizing the cogging torque includes: using the cogging torque phasor to separately calculate the stator teeth 121 in the same sequence position in the plurality of tooth units 12 The cogging torque harmonics are analyzed, and the tooth widths and positions of the stator teeth 121 at the same sequential positions in each tooth unit 12 are modified to eliminate specific sub-cogging torque harmonics.

Specifically, referring to FIG. 6 and FIG. 7 , the Z _f stator teeth 121 at the same sequence position (the stator teeth 121 of the same stripe in FIG. 6 ) inside the Z _f tooth units 12 are respectively divided into a group of cogging torque groups , then the Z _s stator teeth 121 are divided into n _g cogging torque groups, please refer to Fig. 7, and use the cogging torque phasor to compare the teeth of the stator teeth 121 in the same sequence position inside the Z _f tooth unit 12 To analyze the cogging torque harmonics, by changing the tooth width and position of the stator teeth 121 in the same order inside each tooth unit 12, the phase and amplitude of each cogging torque harmonic of each group of cogging torque groups can be changed , to eliminate specific sub-cogging torque harmonics.

Preferably, please refer to Fig. 3 and Fig. 4, as a specific implementation of the magnetic field modulation method of the non-uniform tooth topology permanent magnet vernier motor provided by the present invention, in the adjustment of the same order position inside each of the tooth units 12 In the tooth width and position step of the stator teeth 121, the Z _s stator teeth 121 are set to be equal in width, so as to eliminate the specific sub-harmonic of the cogging torque generated by the Z _s teeth.

Specifically, the Z _s stator teeth 121 are set to be equal in width, and the phase angle distribution of the cogging torque harmonic phasor of n _g groups of cogging torque groups is controlled, so that the cogging torque of each cogging torque group The harmonic phasors are equally spaced to eliminate specific order cogging torque harmonics introduced by the non-uniform distribution of the Z _s stator teeth 121 . In addition, each group of teeth that generate each group of cogging torque phasors is set to a specific pitch to ensure that the cogging torque phasors of each group have equal amplitudes and equal rotation angle distributions, so as to eliminate the cogging rotation generated by Z _s teeth. specific subharmonics of the moment.

Preferably, as a specific implementation of the magnetic field modulation method of the non-uniform tooth topology permanent magnet vernier motor provided by the present invention, after the step of setting the Z _s stator teeth 121 to equal widths, according to each The cogging torque specific sub-harmonic phase of the cogging torque group is calculated to obtain the mechanical offset angle of each of the stator teeth 121 in each of the tooth units 12 relative to the central plane 3 of the tooth unit 12, and the calculation is obtained A target mechanical angle is selected from the plurality of mechanical angles to determine the offset position of each of the stator teeth 121 in each of the tooth units 12 .

Preferably, as a specific implementation of the magnetic field modulation method of the non-uniform tooth topology permanent magnet vernier motor provided by the present invention, after the cogging torque optimization step, the target flux permeance harmonic and the permanent magnet 22 are modulated to obtain Calculate the effective no-load air-gap magnetic density harmonic content of each effective sub, and determine the design point with the highest output torque under the condition of minimum cogging torque.

Specifically, the electromagnetic torque obtained by analyzing and calculating the content of each effective no-load air-gap flux density harmonic modulated by the target permeance harmonic and the permanent magnet 22 satisfies the relational expression:

Among them, k _T is the torque coefficient, is the |Z _r ±mZ _f | sub-harmonic amplitude of the magnetic density corresponding to the winding magnetomotive force, T _e is the electromagnetic torque, B _effect is the effective magnetic density of the air gap, Z _r is the number of pole pairs of the permanent magnet, and Z _f is The number of tooth units, m is a natural number.

Preferably, as a specific embodiment of the magnetic field modulation method of the non-uniform tooth topology permanent magnet vernier motor provided by the present invention, in the adjustment of the teeth of the stator teeth 121 in the same order inside each of the tooth units 12 In the step of width and position, the cogging torque generated by the joint action of the cogging torque groups in the n _g group satisfies the following relational expression:

Among them, T _cog is the cogging torque, k is the kth group of teeth, i is the i-order harmonic of the cogging torque, and T _kiNcog is the amplitude of the i-order harmonic component of the cogging torque generated by the k-th group of teeth , N _cog is the least common multiple of the number of tooth units Z _f and the number of permanent magnet poles 2Z _r , θ _m is the mechanical position angle of the rotor, and α _k is the offset angle of the kth group of teeth relative to the reference point of the stator.

In this step, as shown in Fig. 7 and Fig. 9, according to the division of the tooth units 12 of the Z _s non-uniformly distributed stator teeth 121, the Z _s stator teeth 121 are divided into n _g groups of cogging torque groups, each The group cogging torque group includes Z _f teeth to analyze the cogging torque, so as to solve the problem that the cogging torque becomes larger when the stator teeth 121 are non-uniformly distributed. As shown in FIG. 6 , although the n _g stator teeth 121 inside each tooth unit 12 are non-uniformly distributed, the distribution of the n _g stator teeth 121 inside the Z _f tooth units 12 is the same, and each tooth unit 12 The intervals between the central planes 3 of the Z _f teeth units 12 are the same, at this time, the Z _f stator teeth 121 in the same order position in the Z f tooth units 12 are spaced at the same distance, which is a uniform distribution situation.

Preferably, please refer to FIG. 10 , as a specific implementation of the magnetic field modulation method of the non-uniform tooth topology permanent magnet vernier motor provided by the present invention, after setting the Z _s stator teeth as equal width steps, the The fundamental cogging torque phasors of each group of cogging torque groups are shifted by an angle of α _ng in order to make the overall cogging torque the lowest. Wherein, the α _ng satisfies the relational expression:

Among them, n _g is the group number of the cogging torque group.

At this time, after the cogging torque fundamental wave phasors of each group of the cogging torque groups are sequentially shifted by α _ng angle steps, each harmonic of the cogging torque of each group of the cogging torque groups The phasor satisfies the following relation:

Among them, T _cogk is the cogging torque of the kth tooth group, i is the i-order harmonic of the cogging torque, T _kiNcog is the amplitude of the i-order harmonic component of the cogging torque generated by the k-th group of teeth, N _cog is the least common multiple of the number of tooth units Z _f and the number of permanent magnet poles 2Z _r , θ _m is the mechanical position angle of the rotor, and α _k is the offset angle of the kth group of teeth relative to the reference point of the stator.

When multiple harmonics of cogging torque are considered, the order of fundamental cogging torque is reduced from LCM(Z _s , 2Z _r ) to LCM(Z _f , 2Z _r ) due to the introduction of non-uniform tooth structure, where LCM is The least common multiple, compared with the uniform tooth structure, introduces multiple harmonics. Using the above method, the above newly introduced harmonic content can be eliminated at the same time. The number of stator teeth 121 in each tooth unit 12 is 4, that is, the cogging torque group of n _g group is 4 groups. As shown in the figure, 10, at this time α _ng is 90°, and the amplitude of each phasor is the same. Figure 10 shows the first 4 cases, and the subsequent harmonics cycle in turn. When α _ng is a multiple of 90°, taking a certain time in the cogging torque group as a reference, the l+1th tooth phase can be expressed as l90°. The premise of this method is that l cannot be equal to a multiple of 4. If it is an integer multiple of 4, α _ng is a multiple of 360°, and each harmonic is a superposition relationship, which will maximize the cogging torque. The remaining l values can achieve the effect of eliminating low-order harmonics. This method eliminates the harmonics whose harmonic order is not a multiple of 4 in the cogging torque. It can be seen that the cogging torque fluctuation whose number of times is not equal to the multiple of ngN _cog can be eliminated by this method. At this time, the ngN _cog multiple times fluctuation amplitude is the superposition of the phasor amplitudes of each group of teeth. Among them, N _cog is the cogging torque fundamental wave order for non-uniform teeth.

Preferably, as a specific implementation of the magnetic field modulation method of the non-uniform tooth topology permanent magnet vernier motor provided by the present invention, in the non-uniform distribution tooth structure, the relative position angle of each cogging torque group can be fully Adjusted so that the resulting cogging torque of the stator teeth 121 of each said cogging torque group is minimized. And in the step of using cogging torque phasors to analyze the cogging torque harmonics of n _g groups of cogging torque groups, the phasor phasors of each group of cogging torque groups satisfy the relationship Mode:

in, is the phasor form of the cogging torque of the k-th tooth group, i is the i-order harmonic of the cogging torque, T _kiNcog is the amplitude of the i-order harmonic component of the cogging torque generated by the k-th group of teeth, N _cog is the least common multiple of the number of tooth units Z _f and the number of permanent magnet poles 2Z _r , θ _m is the mechanical position angle of the rotor, and α _k is the offset angle of the kth group of teeth relative to the reference point of the stator.

Preferably, as a specific implementation of the magnetic field modulation method of the non-uniform tooth topology permanent magnet vernier motor provided by the present invention, the plurality of concentrated armature windings wound on the Z _s stator teeth 121 The phases are symmetrical, so that the A-phase sub-winding and the B-phase sub-winding have a phase difference of 120°, and the B-phase sub-winding and the C-phase sub-winding have a 120° phase difference, so that during the operation of the permanent magnet vernier motor, the rotor 2. It will not produce strong unilateral magnetic pull, which reduces the noise of the three-phase motor when it is running at high speed.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention should be included in the protection of the present invention. within range.

Claims (10)

1. The permanent magnet vernier motor with the non-uniform tooth topological structure is characterized by comprising a stator and a rotor, wherein the rotor comprises a rotor frame and a plurality of pairs of permanent magnets arranged on the rotor frame; the stator comprises a stator ring, a plurality of tooth units and a plurality of stator windings, wherein the tooth units and the stator windings are arranged on the stator ring at equal intervals; each tooth unit comprises a plurality of stator teeth, and each stator tooth is provided with a stator winding; the plurality of stator teeth in each tooth unit are symmetrical relative to the central plane of the tooth unit, and the distance between every two adjacent stator teeth in each tooth unit is not equal to the groove pitch of the tooth unit grooves.

2. the non-uniform tooth topology permanent magnet vernier motor as claimed in claim 1, wherein said stator winding is a three-phase symmetric concentrated armature winding.

3. The non-uniform tooth topology permanent magnet vernier motor of claim 1, wherein each of said tooth units comprises n_gThe stator teeth are arranged in sequence, and the number of the tooth units is Z_fthe number of the stator teeth on the stator is Z_sThen, thenWherein Z is_s、Z_f、n_gAre each an integer greater than 1.

4. The non-uniform tooth topology permanent magnet vernier motor as claimed in claim 3, wherein the tooth widths of the stator teeth of a plurality of said tooth units are equal.

5. The non-uniform tooth topology permanent magnet vernier motor of claim 1, wherein the included angle between the central planes of two adjacent tooth units is equal.

6. A magnetic field modulation method for a non-uniform tooth topology permanent magnet vernier motor according to any of claims 1 to 5, comprising introducing a target flux guide harmonic of a frequency corresponding to a winding magnetomotive force harmonic not utilized by a no-load air gap flux density harmonic, and modulating a no-load air gap flux density harmonic by the target flux guide harmonic and the permanent magnet, wherein the no-load air gap flux density harmonic corresponds to the winding magnetomotive force harmonic not utilized by the no-load air gap flux density harmonic.

7. The method for modulating the magnetic field of a non-uniform tooth topology permanent magnet vernier motor according to claim 6, further comprising a winding magnetomotive force harmonic selection step prior to the step of introducing the target permeance harmonic, the winding magnetomotive force harmonic selection step comprising: and under the condition that a plurality of stator teeth are annularly arranged and uniformly distributed at equal intervals, calculating and analyzing the winding magnetomotive force harmonic component of the armature winding, and selecting the winding magnetomotive force harmonic not utilized by the no-load air gap flux density harmonic.

8. The method of claim 6, further comprising a cogging torque optimization step prior to the step of introducing the target permeance harmonic, the cogging torque optimization step comprising: and respectively analyzing the cogging torque harmonic of the stator teeth at the same sequence position in the plurality of tooth units by using the cogging torque phasor, and eliminating the specific sub-cogging torque harmonic by modifying the tooth width and the position of the stator teeth at the same sequence position in each tooth unit.

9. The method for modulating the magnetic field of the non-uniform tooth topology permanent magnet vernier motor according to claim 8, wherein after the step of cogging torque optimization, a design point with the highest output torque is determined by calculating the content of the target flux guide harmonic and each effective sub-no-load air gap flux density harmonic modulated by the permanent magnet under the condition of meeting the minimum cogging torque.

10. The magnetic field modulation method of the non-uniform tooth topology permanent magnet vernier motor according to claim 9, wherein the electromagnetic torque obtained by analyzing and calculating the content of each effective sub no-load air gap flux density harmonic modulated by the permanent magnet and the target flux guide harmonic satisfies the relation:

Wherein k is_TIn order to be the torque coefficient of the motor,Is | Z corresponding to the magnetomotive force of the winding_r±mZ_fI order magnetic density harmonic amplitude, T_eas electromagnetic torque, B_effectEffective flux density of air gap, Z_rNumber of permanent magnet pole pairs, Z_fThe number of the tooth units, and m is a natural number.