Inductance Calculation of Coreless-Type Linear PM Machines Based on Analytical Field Projection and Coil Separation Method

Abstract

The analysis of winding inductance in electric machinery is crucial for both design and control implementations. This article presents an accurate and computationally efficient method to calculate the winding inductance in a coreless-type permanent magnet linear synchronous machine (PMLSM). The analysis is based on the novel approach combining the analytical field projection and the coil separation method. After dividing the coil domain into three regions, a two-dimensional winding inductance in the front view is calculated by solving the field governing equations in each subdomain. Subsequently, the model is extended in three dimensions by projecting the side view of the coil onto the 2-D plane, and the interpolation method is involved in accounting for the end-winding inductance. As a result, the proposed model can save much computation time to evaluate the winding inductance without relying on the finite element (FE) method. In the end, the validity of the analytical model is verified by FE and experimental results.