Analysis of The air gap flux density for IPMSM using Equivalent magnetic circuit

Abstract

Background/Objectives:This paper presents an IPMSM the air gap flux density analysis method using a equivalent magnetic circuit. The validity is verified through comparison of the proposed method and FEM.

Methods/Statistical analysis: The basic model was selected for the IPMSM with an output of 15 kW. The bridge reluctance is assumed to be 2T, ignoring the leakage reluctance of the basic model and the rotor and stator reluctance.The barrier form is finally derived using a equivalent magnetic circuitfor complementing and improving the gap flux density.

Findings:Equivalent magnetic circuit is applied to IPMSM. The equivalent magnetic circuit shows the average of the relative permeability verified by FEM, the relative permeability of the saturated part of the barrier and the value of the stator relative permeability, the leakage magnetic resistance, the rotor magnetic resistance and the stator The assumption is made that magnetic resistance is ignored. In addition, assuming that the flux density of the barrier is 2T, an error occurs between the FEM and the equivalent magnetic circuit. As a result of confirming the equivalent magnetic circuit, the gap flux density is increased by increasing the length of the barrier. Comparing the characteristics of the basic model with the final model complemented by the equivalent magnetic circuit, it can be seen that the torque ripple decreases and the torque increases as the air gap flux density increases.

Improvements/Applications: The air gap flux density is compared with FEM through a equivalent magnetic circuit to derive an improved the air gap flux density through the equivalent magnetic circuit. 

Keywords: IPMSM, equivalent magnetic circuit, FEM, the air gap flux density, saturation.