Novel doubly-salient memory electrical machine

Abstract

The invention relates to a novel doubly-salient memory electrical machine comprising an outer rotor with tooth and an inner stator with tooth, wherein permanent magnets are arranged on the inner stator. The number of tooth Nr of the outer rotor, the number of tooth Ns of the inner stator and the number Np of the permanent magnets should satisfy the relational expression: (m+k1)*Np=Ns=mk2 and 360Nr/Ns=360k3+/-alpha, wherein m is a phase number and is bigger than or equal to 3, alpha is a slot pitch angle the span of which is 0-360 degrees, k1 belongs to an integer from 1 to 1-m, and k2 and k3 are respectively a random positive integer. AlNiCo is adopted as the permanent magnets, and current pulses with different sizes and polarities are charged to a plurality of separated direct current windings to realize on-line magnetism charge demagnetization, thereby realizing multiple functions. Due to the fact that the duration of the current pulse is short, and the induced loss almost can be neglected, as an electromotor, the electrical machine can realize on-line magnetism modulation in the real sense while in running, and as a generator, the electrical machine can realize high-efficiency constant-voltage output while in running.

Description

technical field [0001] The invention relates to a novel double salient pole memory motor suitable for high efficiency, wide speed regulation and square wave drive, which belongs to the field of motor design and manufacture. Background technique [0002] In the 1990s, with the continuous innovation of rare earth permanent magnet materials and power devices, one of the typical representatives of stator permanent magnet motors, the concept of double salient pole permanent magnet (DSPM) motor was proposed by Professor Lipo and gradually improved. The DSPM motor not only has the robustness of the switched reluctance motor, but also can effectively improve the torque density through the bipolar control of the winding current. In the past ten years, a series of fruitful research results have been obtained in the structure design, algorithm theory and drive control of the motor at home and abroad. Especially in motor design, in order to increase the motor's field-weakening speed ex...

AI Technical Summary

Problems solved by technology

Especially in motor design, in order to increase the motor's field-weakening speed expansion capability, methods including mechanical magnetic separation, split winding and hybrid excitation have been proposed. The former two bypass part of the permanent magnet flux and Reduce the number of winding turns to achieve the effect of speed expansion, and the structure is slightly complicated

The latter directly uses the magnetic potential of the field winding to weaken the permanent magnet flux, but the continuous field current will generate additional losses

[0003] Conventional DSPM motors mostly adopt concentrated winding design, and each permanent magnet on the stator corresponds to an integer multiple of phase windings, resulting in different magnetic flux paths of each phase winding, resulting in deviations in the opposite potentials

Secondly, in conventionally designed DSPM motors, since each series coil is located at the same position relative to the rotor, the maximum and minimum values ​​of each phase flux linkage are respectively located at the positions where the stator teeth align with the center of the rotor teeth and the center of the slot. Due to the saturation of the core, When the former passes through, the change range of the flux linkage is smaller than the latter, which leads to the left-right asymmetry of the back EMF waveform of the DSPM motor

Thirdly, since the relative positions of the series coils of each phase winding and the rotor slots are kept synchronized at all times, the self-inductance of each coil changes in the same direction with the rotor position, which intensifies the fluctuation of the self-inductance of each phase, resulting in reluctance Increase in torque and torque ripple

[0004] Therefore, how to solve the asymmetry of the magnetic circuit of the DSPM motor, the large torque ripple and how to realize the adjustment of the air gap magnetic field in a wider range more conveniently and efficiently are research hotspots and difficulties.

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