CN204967578U - Reduce PMSM torque ripple's rotor structure - Google Patents

Abstract

The utility model relates to a reduce PMSM torque ripple's rotor structure, a plurality of pole pairs of rotor, its characterized in that are placed in even including the rotor with along rotor circumference: every pole pair comprises two polarity identical's permanent magnet and two permanent magnet symmetrical arrangements are the V font, the polarity of adjacent pole pair is opposite, the rotor corresponds the position of permanent magnet and has seted up the permanent magnet groove, the rotor corresponds permanent magnet groove both ends position and sets up its and communicating air flux barrier, form between two air flux barrier bottom the V font with being close to of a pair of magnetic pole and separate the magnetic bridge and separate magnetic bridge both sides face parallel, the top that is close to V font division actinal air flux barrier is parallel with corresponding rotor outer peripheral face, little lightening hole has been seted up to the position that the rotor corresponds between every pole pair and the rotor shaft, big lightening hole has been seted up to the position that the rotor corresponds between two little lightening holes, greatly, little lightening hole uses the rotor shaft to distribute as central symmetry respectively. Its simple structure, use are reliably.

Description

Rotor Structure for Reducing Torque Ripple of Permanent Magnet Synchronous Motor

technical field

The utility model relates to a permanent magnet synchronous motor rotor, in particular to a rotor structure for reducing the torque fluctuation of the permanent magnet synchronous motor.

Background technique

Permanent magnet synchronous motor has high efficiency, high output torque, high power density and good dynamic performance, and is widely used in the automobile industry. Since the permanent magnet of the built-in permanent magnet motor is buried in the rotor core, it has a protective effect against demagnetization during weak magnetic operation, so the built-in permanent magnet motor is less likely to demagnetize than the surface-mounted permanent magnet motor. At the same time, because the d-axis inductance of the built-in permanent magnet motor is larger than that of the surface-mounted permanent magnet motor, and the d-axis inductance is smaller than the q-axis inductance, it has reluctance torque, so it has a wider constant power range and excellent weak magnetic speed expansion capability , very suitable for high torque output at low speed or climbing, high power output at high speed, wide speed range and high reliability vehicle environment.

The ride comfort of a car is an important indicator to measure the overall performance of the car. If the ride comfort of the car is not good, the occupants will vibrate with the body and cause fatigue and discomfort. Therefore, under ideal conditions, in order to generate a constant electromagnetic torque, the electromotive force of the permanent magnet synchronous motor is required to be a sine wave. However, due to the asymmetry of the magnetic circuit of the built-in permanent magnet synchronous motor, the waveform of the excitation magnetic field is seriously distorted, resulting in the motor torque If the fluctuation is too large, it will seriously affect the ride comfort of the car. How to reduce the torque fluctuation of the built-in permanent magnet synchronous motor has become a hot spot of current research. CN103560636A discloses a method for reducing the torque fluctuation of the permanent magnet motor for electric vehicles, but it is to reduce the torque fluctuation by controlling the tooth edge thickness of the stator teeth. The torque fluctuation of the motor, this application focuses on changing the rotor structure to reduce the torque fluctuation of the motor.

Contents of the invention

The purpose of the utility model is to provide a rotor structure for reducing the torque fluctuation of the permanent magnet synchronous motor under the condition of constant rated output torque, which is simple in structure and reliable in use.

The technical scheme of the utility model is:

A rotor structure for reducing the torque fluctuation of a permanent magnet synchronous motor, including a rotor and a plurality of magnetic pole pairs uniformly built into the rotor along the circumferential direction of the rotor, characterized in that each magnetic pole pair is composed of two permanent magnets with the same polarity And the two permanent magnets are symmetrically arranged in a V shape, and the polarities of the adjacent pairs of magnetic poles are opposite. Air magnetic isolation slots, a magnetic isolation bridge is formed between two air magnetic isolation slots near the V-shaped bottom of the same pair of magnetic poles, and the two sides of the magnetic isolation bridges are parallel, and the top of the air magnetic isolation slots near the V-shaped opening side and the corresponding The outer peripheral surface of the rotor is parallel, and the rotor is provided with a small weight-reducing hole corresponding to the position between each magnetic pole pair and the rotor shaft, and the rotor is provided with a large weight-reducing hole corresponding to the position between the two small weight-reducing holes. The large and small lightening holes are symmetrically distributed around the rotor shaft.

In the above-mentioned rotor structure for reducing the torque fluctuation of the permanent magnet synchronous motor, the small weight-reducing hole is a circular hole, and the center of the circle coincides with the symmetrical center line of the corresponding magnetic pole pair.

In the above-mentioned rotor structure for reducing torque fluctuations of permanent magnet synchronous motors, the center line of symmetry of the large weight-reducing hole coincides with the center line of symmetry of two adjacent magnetic pole pairs.

In the above-mentioned rotor structure for reducing the torque fluctuation of the permanent magnet synchronous motor, the edge of the permanent magnet slot is additionally provided with a tail positioning groove.

In the above-mentioned rotor structure for reducing the torque fluctuation of the permanent magnet synchronous motor, the angle between the two permanent magnets of the same pair of magnetic poles is 124°-126°.

In the above-mentioned rotor structure for reducing the torque fluctuation of the permanent magnet synchronous motor, the permanent magnets are rectangular NdFeB magnetic blocks with the same size.

The beneficial effects of the utility model are: when the permanent magnet synchronous motor is running, the induced electromotive force of the same order and the current harmonic will produce an average torque, and the harmonic electromotive force and current of different orders will produce a pulsating harmonic torque, thereby generating mechanical and Electromagnetic noise affects the smooth operation and reliability of the motor. The rotor structure described in this application adopts a built-in radial magnetic circuit structure, which maintains the reluctance torque generated by the asymmetrical magnetic circuit of the traditional built-in permanent magnet motor to improve the overload capacity and power density of the motor, while ensuring the air-gap magnetic Under the condition that the density remains unchanged, the magnetic circuit is optimized by setting weight-reducing holes and improving the air isolation groove, so that the distortion rate of the air-gap magnetic density waveform is reduced, and the torque fluctuation of the motor is reduced. Among them, the layout design of the weight-reducing holes, under the condition of ensuring the strength of the rotor, on the one hand reduces the moment of inertia of the rotor and improves the control accuracy, on the other hand reduces the leakage flux, makes the magnetic circuit distribution reasonable, and reduces the flux density harmonic content.

Description of drawings

Fig. 1 is the structural representation of the utility model;

Fig. 2 is a schematic diagram comparing air-gap flux density waveforms of motors adopting the rotor structure of the present application and not adopting the rotor structure of the present application;

Fig. 3 is a schematic diagram comparing the no-load back electromotive force harmonic analysis using the rotor structure of the present application and not using the rotor structure of the present application.

In the figure: 1. Rotor, 2. Permanent magnet, 3. Permanent magnet slot, 4. Air isolation slot, 5. Magnetic isolation bridge, 6. Rotor shaft, 7. Small weight reduction hole, 8. Large weight reduction hole, 9. Tail positioning groove.

detailed description

As shown in Figure 1, the rotor structure for reducing the torque fluctuation of the permanent magnet synchronous motor includes a rotor 1 and a plurality of magnetic pole pairs uniformly built in the rotor 1 along the circumferential direction of the rotor 1, and each magnetic pole pair is composed of two pieces with the same polarity Composed of permanent magnets 2 and two permanent magnets 2 are symmetrically arranged in a V shape, and the angle between the two permanent magnets 2 of the same pair of magnetic poles is 124°-126°. The polarities of adjacent magnetic pole pairs are opposite, and the position corresponding to the permanent magnet 2 of the rotor 1 is provided with a permanent magnet slot 3, and the position of the two ends of the rotor 1 corresponding to the permanent magnet slot 3 is provided with an air isolation slot 4 communicating with it, A magnetic isolation bridge 5 is formed between the two air magnetic isolation slots 4 near the V-shaped bottom of the same pair of magnetic poles, and the two sides of the magnetic isolation bridge 5 are parallel, and the top of the air magnetic isolation slot 4 near the V-shaped opening side is connected to the corresponding rotor. 1 The outer peripheral surface is parallel, the rotor 1 is provided with a small weight reduction hole 7 corresponding to the position between each magnetic pole pair and the rotor shaft 6, and the rotor 1 is provided with a large weight reduction hole 7 corresponding to the position between the two small weight reduction holes 7 The heavy holes 8, the large and small lightening holes 8, 7 are respectively symmetrically distributed around the rotor shaft 6. The small lightening hole 7 is a circular hole, and its center coincides with the symmetrical center line of the corresponding magnetic pole pair. The centerline of symmetry of the large lightening hole 8 coincides with the centerline of symmetry of two adjacent magnetic pole pairs. The edge of the permanent magnet slot 3 is additionally provided with a tail positioning groove 9 . In this embodiment, the permanent magnets 2 are rectangular NdFeB magnets with the same size, and the angle between the two permanent magnets 2 of the same pair of magnetic poles is 126°.

After the rotor structure of the present application is optimized, the minimum torque fluctuation in the constant torque range of the permanent magnet synchronous motor that does not adopt the rotor structure of the present application is reduced from the original 9% to 2.5%, and the maximum torque fluctuation in the constant power range is reduced from the original 50%. % reduced to 14%. The torque fluctuation in the motor performance is effectively suppressed, which greatly improves the quality of the motor, effectively improves the overall performance of the motor, and realizes low torque fluctuation and stable operation of the permanent magnet synchronous motor, see Figure 2 and Figure 3.

Claims (6)

1. one kind is reduced the rotor structure of permagnetic synchronous motor torque ripple, comprise rotor and be evenly built in a plurality of pole pairs in rotor along periphery of rotor, it is characterized in that: each pole pair is made up of the permanent magnet that two pieces of polarity is identical and two pieces of permanent magnet symmetric arrays are in the shape of the letter V, the polarity of adjacent pole pair is contrary, the position of the corresponding permanent magnet of described rotor offers permanent magnet trough, the corresponding permanent magnet trough end positions of described rotor offers itself and the air magnet isolation tank communicated, to be formed every magnetic bridge and parallel every magnetic bridge two sides with between two air magnet isolation tanks bottom the close V-shaped of a pair magnetic pole, top near the air magnet isolation tank of v-shaped openings side is parallel with corresponding rotor outer periphery face, position between the corresponding each pole pair of described rotor and armature spindle offers little lightening hole, position between corresponding two the little lightening holes of described rotor offers large lightening hole, greatly described, little lightening hole is symmetrical centered by armature spindle respectively.

2. the rotor structure of reduction permagnetic synchronous motor torque ripple according to claim 1, it is characterized in that: described little lightening hole is circular hole, and its center of circle overlaps with the symmetrical center line of corresponding pole pair.

3. the rotor structure of reduction permagnetic synchronous motor torque ripple according to claim 1, is characterized in that: the symmetrical center line of described large lightening hole overlaps with the symmetrical center line of adjacent two pole pairs.

4. the rotor structure of reduction permagnetic synchronous motor torque ripple according to claim 1, is characterized in that: described permanent magnet trough edge is separately provided with afterbody positioning groove.

5. the rotor structure of reduction permagnetic synchronous motor torque ripple according to claim 1, is characterized in that: the angle with two pieces of permanent magnets of a pair magnetic pole is 124 °-126 °.

6. the rotor structure of reduction permagnetic synchronous motor torque ripple according to claim 1, is characterized in that: described permanent magnet is the rectangle ndfeb magnet of consistent size.