阅读说明：本技术 一种奇数极三相游标永磁直线电机 (Odd-pole three-phase vernier permanent magnet linear motor ) 是由 李大伟 李睿 曲荣海 石超杰 周游 于 2019-11-11 设计创作，主要内容包括：本发明公开了一种奇数极三相游标永磁直线电机,包括：电枢绕组、初级铁心轭部、初级铁心齿部、永磁磁极和次级铁心；永磁磁极阵列均匀分布在次级铁心上,且相邻永磁磁极极性相反；电枢绕组、初级铁心轭部和初级铁心齿部组成电机初级；永磁磁极和次级铁心组成电机次级；直线电机初级与次级之间存在气隙,两者可以相互移动。本发明取消了传统游标永磁直线电机中有效永磁磁极数为偶数的约束,提出了奇数极概念,使永磁直线电机有效磁极数可以为奇数,扩充了可能的极槽配合方案,提高了直线电机设计自由度。本发明在保持游标永磁直线电机的高推力密度特性的同时,降低了水平推力波动和纵向磁拉力波动,有助于提高电机的控制精度和响应速度。(The invention discloses an odd pole three-phase vernier permanent magnet linear motor, which comprises: the permanent magnet motor comprises an armature winding, a primary iron core yoke part, a primary iron core tooth part, a permanent magnet magnetic pole and a secondary iron core; the permanent magnetic pole arrays are uniformly distributed on the secondary iron core, and the polarities of the adjacent permanent magnetic poles are opposite; the armature winding, the primary iron core yoke part and the primary iron core tooth part form a primary motor; the permanent magnetic pole and the secondary iron core form a secondary of the motor; an air gap exists between the primary and the secondary of the linear motor, and the primary and the secondary can move mutually. The invention cancels the constraint that the number of the effective permanent magnet poles in the traditional vernier permanent magnet linear motor is even, provides the concept of odd poles, ensures that the number of the effective permanent magnet poles of the permanent magnet linear motor can be odd, expands the possible pole slot matching scheme and improves the design freedom of the linear motor. The invention reduces the horizontal thrust fluctuation and the longitudinal magnetic tension fluctuation while keeping the high thrust density characteristic of the vernier permanent magnet linear motor, and is beneficial to improving the control precision and the response speed of the motor.)

1. The utility model provides an odd utmost point three-phase vernier permanent magnet linear motor which characterized in that includes: the permanent magnet motor comprises an armature winding (1), a primary iron core yoke part (2), a primary iron core tooth part (3), a permanent magnet magnetic pole (4) and a secondary iron core (5);

the multi-phase armature winding (1) surrounds the primary iron core tooth part (3); the primary iron core yoke part (2) and the primary iron core tooth part (3) form a primary iron core of the motor; the permanent magnet poles (4) with the same size are uniformly distributed on the secondary iron core (5) along the primary motion direction of the motor to form a permanent magnet array, and the polarities of the adjacent permanent magnet poles are opposite.

2. The odd-pole three-phase vernier permanent magnet linear motor of claim 1 wherein the effective number of permanent magnet poles 2P corresponding to the primary of the linear motor_fIs odd number, P_fIs a true score with a denominator of 2; an air gap exists between the primary motor and the secondary motor, and the primary motor and the secondary motor can move mutually.

3. The odd-pole three-phase vernier permanent magnet linear motor of claim 2 wherein the motor effective permanent magnet pole number is 2P_fPrimary core slot number Z_sPole pair P with armature winding_aThe number satisfies the magnetic field modulation principle: p_a＝|P_f±Z_s|。

4. The odd-pole three-phase vernier permanent magnet linear motor as claimed in any one of claims 1 to 3, wherein the number of pole pairs P of the armature winding of the vernier permanent magnet linear motor_aPrimary core slot number Z_sAnd the phase number m of the winding satisfies the relation:

wherein k is an arbitrary integer, and GCD is calculated by taking the greatest common divisor.

5. An odd pole two phase vernier permanent magnet linear motor as claimed in any of claims 1 to 4 wherein the pole slot matching of the motor is determined from a slot number radial diagram.

6. The odd-pole two-phase vernier permanent magnet linear motor as claimed in claim 5 wherein the partial slot potentials are reversed to form a complete 180 ° phase band, and are symmetrically divided into a plurality of phase bands, the number of motor phases being the number of symmetrical phase bands.

7. The odd-pole two-phase vernier permanent magnet linear motor as claimed in any one of claims 1 to 6, wherein the order of the fundamental wave of the electromagnetic force ripple with respect to the electrical frequency of the fundamental wave

Wherein, 2P_fNumber of effective permanent magnet poles Z of motor_sNumber of primary core slots, P_aAre armature winding pole pairs.

Technical Field

The invention belongs to the technical field of permanent magnet motors, and particularly relates to an odd-pole three-phase vernier permanent magnet linear motor.

Background

Compared with a scheme that the linear motion is formed by a rotating motor and a ball screw, the scheme that the linear motion is directly generated by the linear motor has a simpler structure, higher efficiency and better stability. Therefore, linear motors are increasingly favored in industrial fields requiring linear motion. The linear motor is classified into a linear induction motor and a linear permanent magnet motor. Compared with a linear induction motor, the linear permanent magnet motor has better thrust density, power factor and efficiency performance. Among numerous linear motor topologies, the vernier permanent magnet linear motor adopting the principle of the permanent magnet and the vernier motor has the characteristics of simple structure and high efficiency of the permanent magnet motor and the characteristics of low speed and high torque of the vernier motor, so that the vernier permanent magnet linear motor attracts attention in recent years.

As shown in fig. 1, the pole-slot mating of a linear motor is typically designed from an equivalent rotating electrical machine. In a rotating electrical machine, since the mechanical positions of 0 electrical degrees and 360 electrical degrees coincide, the number of permanent magnet poles of the machine must be even, so that the electrical angle of the machine varies periodically around the circumference of the machine. Since linear motors come from equivalent rotating machines, the same constraint (i.e., an even number of motor permanent magnet poles) is often followed in the design of linear motors, which is actually a redundant constraint. Meanwhile, the pole slot matching design of the integral poles of the traditional vernier permanent magnet linear motor also has the problem of long end part of the motor. In the linear motor, because the mechanical positions of 0 electrical angle and 360 electrical angle are not coincident, the number of the permanent magnetic poles in the effective length of the rotor can be selected to be odd. Without the constraint of the number of dipoles, the linear permanent magnet motor has more new pole slot matching choices.

When the linear permanent magnet vernier motor operates, longitudinal magnetic tension is generated between the permanent magnet magnetic pole and the primary side of the linear motor; meanwhile, due to the influence of the inherent edge-end effect of the traditional permanent magnet linear motor, the electromagnetic thrust and the longitudinal magnetic tension in the operation process of the permanent magnet linear motor have large fluctuation. The fluctuating longitudinal magnetic pull force not only can increase the deformation risk of a motor guide rail and a system supporting component, but also introduces a variable resistance to the system, increases the control difficulty of the motor, and reduces the control precision and response speed of the system.

Generally speaking, because the traditional vernier permanent magnet linear motor is evolved from a rotary vernier permanent magnet motor, in the design process of pole slot matching, the constraint that the number of poles in the effective range of the motor is even can still be followed, and the constraint is actually redundant, and the problem that the end part is too long exists. Meanwhile, the longitudinal magnetic tension of the traditional vernier permanent magnet linear motor fluctuates greatly in the operation process.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides an odd-pole three-phase vernier permanent magnet linear motor, aiming at canceling the constraint that the number of poles in the effective range of the vernier permanent magnet linear motor is even, increasing the design freedom of the vernier permanent magnet linear motor and comprehensively reducing the fluctuation of the horizontal electromagnetic thrust and the fluctuation of the longitudinal magnetic tension of the vernier permanent magnet linear motor.

The invention provides an odd-pole three-phase vernier permanent magnet linear motor, which comprises: an armature winding, a primary core yoke, a primary core tooth, a permanent magnet pole and a secondary core; the multi-phase armature winding surrounds the primary iron core tooth part; the primary iron core yoke part and the primary iron core tooth part form a primary iron core of the motor; and a plurality of permanent magnet poles with the same size are uniformly distributed on the secondary iron core along the primary motion direction of the motor to form a permanent magnet array, and the polarities of the adjacent permanent magnet poles are opposite.

Furthermore, the primary of the linear motor corresponds to the effective permanent magnet pole number 2P_fIs odd number, P_fIs a true score with a denominator of 2; an air gap exists between the primary motor and the secondary motor, and the primary motor and the secondary motor can move mutually.

Further, the effective permanent magnet pole number of the motor is 2P_fPrimary core slot number Z_sPole pair P with armature winding_aThe number satisfies the magnetic field modulation principle: p_a＝|P_f±Z_s|。

Furthermore, the armature winding pole pair number P of the vernier permanent magnet linear motor_aPrimary core slot number Z_sAnd the phase number m of the winding satisfies the relation:

wherein k is an arbitrary integer, and k is an integer,the GCD is calculated by taking the greatest common divisor.

Further, the pole-slot fit of the motor is determined according to the slot number star map.

Furthermore, after the potential of partial slots is reversed, a complete 180-degree phase belt is formed and symmetrically divided into a plurality of phase belts, and the number of motor phases is the number of symmetrical phase belts.

Further, the order of the fundamental wave of the electromagnetic force fluctuation with respect to the electrical frequency of the fundamental wave

Wherein, 2P_fNumber of effective permanent magnet poles Z of motor_sNumber of primary core slots, P_aAre armature winding pole pairs.

Through the technical scheme, compared with the prior art, the invention has the following beneficial effects:

the motor structure provided by the invention innovatively cancels the limitation that the number of the permanent magnet poles in the primary effective range of the linear motor is even, and provides the concept of odd poles, so that the number of the permanent magnet poles in the effective length of the rotor of the permanent magnet linear motor can be selected to be odd, the permanent magnet linear motor has more pole slots to be matched and selected, and the design freedom degree of the permanent magnet linear motor is increased.

The motor structure provided by the invention can effectively reduce the horizontal electromagnetic thrust fluctuation and the longitudinal magnetic tension fluctuation of the motor, reduce the disturbance of the linear motor in the operation, reduce the control difficulty of the motor, improve the control precision and the operation efficiency of the linear motor and shorten the response time of a system.

In the motor structure provided by the invention, the size of the iron core teeth close to the end part can be properly adjusted, a new design freedom degree is introduced, and the optimization of the linear motor on thrust fluctuation is facilitated.

The invention provides a novel pole slot matching, which can effectively shorten the end length of the motor, improve the motor efficiency and power factor, reduce the motor manufacturing cost, make a linear motor system more compact and improve the motor output density.

Drawings

FIG. 1 is a schematic diagram of a linear motor designed from an equivalent rotating electrical machine;

fig. 2 is a schematic cross-sectional structure view of an odd-pole vernier permanent magnet linear motor and its winding arrangement according to the present invention;

fig. 3 is a no-load magnetic field distribution of the odd pole vernier permanent magnet linear motor according to the present invention;

fig. 4 is a slot potential star diagram of the odd pole vernier permanent magnet linear motor and its winding phase splitting proposed by the present invention;

FIG. 5 is a schematic diagram of an unloaded back emf waveform of the armature winding;

FIG. 6 is a schematic diagram of the harmonic content distribution in the no-load back emf waveform of the armature winding;

FIG. 7 is an average electromagnetic thrust of an odd pole vernier permanent magnet linear motor under different load conditions;

fig. 8 shows longitudinal magnetic tension waveforms under rated load of the odd pole vernier permanent magnet linear motor.

Wherein: 1 is an armature winding, 2 is a primary iron core yoke, 3 is a primary iron core tooth, 4 is a permanent magnet magnetic pole, and 5 is a secondary iron core.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Aiming at the defects of the prior art, the invention aims to provide an odd-pole three-phase vernier permanent magnet linear motor shown in fig. 2, and aims to cancel the constraint that the number of poles in the effective range of the vernier permanent magnet linear motor is even, increase the design freedom of the vernier permanent magnet linear motor and comprehensively reduce the fluctuation of the horizontal electromagnetic thrust and the fluctuation of the longitudinal magnetic tension of the vernier permanent magnet linear motor.

In order to achieve the above object, the present invention introduces an odd-pole concept, and provides an odd-pole three-phase vernier permanent magnet linear motor, comprising: a multi-phase armature winding, a primary core yoke, a primary core tooth, a permanent magnet pole, and a secondary core;

the armature winding surrounds the iron core slots between the primary iron core teeth; the permanent magnetic poles are uniformly distributed on the secondary iron core to form a permanent magnet array, and the polarities of the adjacent permanent magnetic poles are opposite;

the armature winding, the primary iron core tooth part and the primary iron core yoke part jointly form a primary of the vernier permanent magnet linear motor; the permanent magnet array and the secondary back iron form the secondary of the vernier permanent magnet linear motor; an air gap exists between the primary and the secondary of the vernier permanent magnet linear motor, so that the vernier permanent magnet linear motor and the secondary can move mutually; the number of the permanent magnet magnetic poles of the corresponding secondary stage in the primary effective range of the vernier permanent magnet linear motor is odd;

irrespective of the end effect, the electromotive forces induced in each primary core slot are equal in magnitude, identical in waveform, but different in phase in time. In the design process of the motor, the pole-slot coordination of the motor is often designed by using a slot number star diagram as shown in fig. 4. The number of each vector in the slot number star diagram is the same as that of the corresponding core slot, and a mark is arranged before the number, which indicates that the conductors in the core slot are in reverse series connection, and the corresponding slot electromotive force vector is also in reverse direction, namely in forward series connection. The vector length represents the amplitude of the fundamental component of the induced electromotive force in the slot, and the included angle between the vectors is the phase difference (electrical angle) between the induced electromotive forces in the iron core slot. After the potential vector of a part of slots is reversed, the star diagram of the slot number of the odd-pole three-phase vernier permanent magnet motor can be symmetrically divided into A, B, C three phase belts, and the three phase belts correspond to A, B, C two phases in an armature winding.

In a traditional vernier permanent magnet linear motor, the principle of distribution of each phase winding meets the following principle:

wherein Z_sNumber of primary core slots, P_aThe number of the armature winding poles is shown, GCD is the operation of taking the greatest common divisor, m is the number of the armature winding phases, and k is any integer.

After introducing the odd pole concept, the armature winding polesNumber P_aNot an integer, so the winding assignment relationship should be changed as follows:

number of permanent magnet poles 2P_fThe number Z of primary iron core slots of the motor_sNumber of pole pairs P with armature winding_aThe magnetic field modulation principle is satisfied: p_a＝|P_f±Z_s|。

After the introduction of the odd pole concept, the freedom of motor design is improved, P_aThe range of values that can be taken is expanded, and the expanded pole slot fit is as follows:

wherein G is the polar ratio, and the calculation formula is as follows:

N_cfor the order of the fundamental wave of electromagnetic force fluctuation relative to the electrical frequency of the fundamental wave, the calculation formula of the traditional vernier permanent magnet linear motor is as follows:

wherein LCM is the least common multiple operation.

After introducing the odd-pole concept, N_cThe calculation of (d) should be rewritten as:

positioning force F borne by primary permanent magnet linear motor in no-load state_xAnd longitudinal magnetic pull force F_yCan be expressed as:

wherein F_xi，F_yiThe amplitudes of i-th harmonic waves of the electromagnetic thrust and the longitudinal magnetic tension are respectively, and tau is the polar distance of the permanent magnetic pole;

after rewriting the formula, in the design of polar-groove fit, N_cIt is easier to take larger values. Because the harmonic amplitude of the electromagnetic thrust and the longitudinal magnetic pull is in inverse proportion to the number of the harmonic, the fluctuation of the electromagnetic thrust and the longitudinal magnetic pull of the odd-pole vernier permanent magnet linear motor is obviously improved compared with the fluctuation of the conventional vernier permanent magnet linear motor.

The odd-pole three-phase permanent magnet vernier linear motor adopts double-layer short-distance windings, but only one layer of windings is arranged in two iron core slots at the primary side end of the motor, so that the size of iron core teeth of the linear motor close to the primary end part can be properly adjusted, and the electromagnetic force fluctuation of the linear motor can be better optimized;

after introducing the odd pole concept, in the pole slot matching of the linear motor, a parameter y representing the length of the end part of the motor₁/Z_sSmaller values may be taken. The introduction of the odd pole concept is beneficial to shortening the end length of the motor, reducing the copper loss and the magnetic flux leakage of the winding of the electrode, improving the operation efficiency and the power factor of the motor and reducing the manufacturing cost of the motor. The shorter end part can also make the linear motor system more compact and improve the thrust density of the linear motor;

optionally, the primary iron core of the motor is a rotor iron core, and the magnetic pole iron core is a stator iron core.

Optionally, the primary iron core of the motor is a stator iron core, and the magnetic pole iron core is a rotor iron core.

To further explain the odd-pole three-phase vernier permanent magnet linear motor provided by the embodiment of the present invention, the following is detailed with reference to the accompanying drawings with specific examples:

referring to fig. 2, an embodiment of the present invention provides an odd-pole vernier permanent magnet linear motor, and sets a pole-slot coordination through a slot potential diagram, including: an armature winding 1, a primary iron core yoke 2, primary iron core teeth 3, a permanent magnet pole 4 and a secondary iron core 5; the armature winding 1 surrounds the primary iron core teeth 3; the primary iron core yoke part 2 and the primary iron core teeth 3 form a primary iron core of the motor; a plurality of permanent magnet poles 4 with the same size are uniformly distributed on the secondary iron core 5 to form a permanent magnet array, and the polarities of the adjacent permanent magnet poles are opposite; the armature winding 1, the primary iron core yoke 2 and the primary iron core teeth 3 jointly form a primary of the linear motor; the permanent magnet pole 4 and the pole core 5 jointly form a motor secondary. An air gap exists between the primary and the secondary of the motor, so that the primary and the secondary can move mutually.

The tooth part in the invention can be regarded as a modulation block of a permanent magnetic pole, and the function of magnetic field modulation is realized. Effective permanent magnet pole number 2P corresponding to primary iron core of motor_fThe number Z of primary iron core slots of the motor_sNumber of pole pairs P with armature winding_aThe magnetic field modulation principle is satisfied, namely: p_a＝|P_f±Z_sL. Figure 2 shows the number Z of primary iron core slots of the motor in the odd-pole vernier permanent magnet linear motor_s18, the number of effective permanent magnet poles 2P corresponding to the primary_fAs shown in fig. 29, according to the principle of the vernier permanent magnet linear motor, the number of pole pairs of the armature winding generated after the permanent magnet field is modulated by the split teeth is P_aThe i 14.5-18 i 3.5 is coupled with an armature winding, the modulated magnetic field distribution is shown in fig. 3, and the slot vector diagram and the winding arrangement of the 18-slot 29-pole odd-pole vernier permanent magnet linear motor are shown in fig. 4.

The odd pole vernier permanent magnet linear motor is a three-phase motor, and the analysis of three opposite electromotive forces of a winding and harmonic waves thereof are respectively shown in fig. 5 and 6. The average electromagnetic thrust and the rated longitudinal magnetic pull force waveforms of the odd pole vernier permanent magnet linear motor under different load conditions are respectively shown in fig. 7 and 8.

The primary iron core of the motor can be a rotor iron core, and correspondingly, the secondary iron core is a stator iron core; the primary iron core of the motor can also be a stator iron core, and correspondingly, the secondary iron core is a rotor iron core.

Number of slots Z of motor in the invention_sIs the equivalent slot number, i.e. the number of slot vectors in the slot potential star diagram.

The motor provided by the invention can be applied to occasions needing linear motion with high thrust or high dynamic response, such as but not limited to transmission systems, servo systems, oil pumping units, electromagnetic ejection devices, plotters, elevators, wave power generation systems and the like.

It will be understood by those skilled in the art that the foregoing is only a preferred embodiment of the present invention, and is not intended to limit the invention, and that any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the present invention.