Notch Optimization Design of Rotor for Cogging Torque Reduction of the IPMSM

Abstract

Background/Objectives: IPMSM is currently used in many industries. However, due to the unusual structure of the permanent magnet embedded in the rotor, high cogging torque occurs.

Methods/Statistical analysis: This paper obtains data using finite element method. We propose a suitable magnetic circuit for this model and derive precise mathematical data through MATLAB. By simplifying the structure of the model, it is convenient to compare the simulation results with the equations derived from the magnetic circuit. Experimental design was used to optimize the shape of the notch.

Findings: The motor adopted as the basic model in this paper is the motor in mass production. Simplify the effects of the notch by simplifying this motor rather than directly interpreting it.

We make mathematical calculation method through magnetic circuit and compare the formula with the result of derivation and finite element method using MATLAB. The experimental design method is then used to derive the optimal shape of the notch and compare it with the proposed mathematical model. The error rate is set at about 1 percent and the study is conducted. The experimental design method uses the Taguchi technique and mentions how to minimize cogging torque by applying two notches (in the rotor) just above the magnet concentrator. Cogging torque by shape (parameters) is examined and the notch effect is considered by finding the optimal point and reflecting it in notch shape.

The expected effect of the future can be easily predicted the cogging torque of this model through mathematical formulas and experimental design.

Improvements/Applications: The proposed theory is that the cogging torque can be easily confirmed by using the experimental design through the equation. This theory is also applicable to the IPMSM type.

Keywords: Coggingtorque, Notch, Magneticcircuit, IPMSM,DOE.