Square-wave rotor based on permanent magnet and inner rotor core eccentric structure design

Abstract

The invention relates to the technical field of motors or generators, and specifically discloses a square-wave rotor designed based on permanent magnets and an eccentric structure of an inner rotor core; it includes an outer rotor core, an eccentric permanent magnet, an inner rotor core, and a rotor shaft, and multiple The permanent magnets are placed alternately along the radial inner side of the outer rotor core. The eccentric permanent magnet is composed of an arc-shaped outer profile, an eccentric arc inner profile and two sides. The inner rotor core has a circular inner profile and a set of eccentric permanent magnets. Composed of circular arcs, an annular air gap is formed between the radially outer side of the inner rotor core and the eccentric permanent magnet; the invention adopts a rotor designed based on the eccentric structure of the permanent magnet and the inner rotor core, so that the radial air gap of the flywheel generator The length of the two sides is not uniform, and the length change of the radial sides of the air gap is more reasonable, which improves the air-gap magnetic density waveform of the flywheel generator, making the air-gap magnetic field close to a square wave, thereby improving the hollow cup flywheel Generator back electromotive force waveform reduces torque ripple.

Description

technical field [0001] The invention relates to the technical field of generators, and specifically discloses a square-wave rotor designed based on a permanent magnet and an eccentric structure of an inner rotor iron core. Background technique [0002] Traditional square-wave energy storage flywheel generators are mostly used in low-speed and high-load applications. They are driven and controlled by square-wave phase currents. Square-wave phase currents need to interact with square-wave opposite electromotive forces to reduce electromagnetic torque ripple. However, the traditional hollow cup type square wave energy storage flywheel generator has a large difference between the back electromotive force waveform and the square wave, which causes the energy storage flywheel generator to generate electromagnetic torque pulsation, which affects the performance and efficiency of the energy storage flywheel generator. From this point of view, it is very important to optimize the str...

AI Technical Summary

Problems solved by technology

[0003]The existing authorized national invention patent has disclosed a brushless DC motor without a stator iron core, and the hollow cup stator structure can be used in the design of the brushless DC motor , so that the inner eccentric and outer rotor cores rotate synchronously with the eccentric permanent magnets, so that there will be no loss in the cores. At the same time, the hollow cup stator makes the stator a cogging-free structure, which can eliminate cogging torque and tooth harmonics; Stator iron-core brushless DC motors have uniform lengths on both radial sides of the air gap, resulting in consistent radial air-gap reluctance, which affects the distribution of the air-gap magnetic field, making the air-gap magnetic field waveform different from the square wave. Due to the eccentric permanent magnet Direct contact between poles will generate magnetic flux leakage between poles, which will affect the performance of the flywheel generator

Images