An Analytical Subdomain Model for Dual-Rotor Permanent Magnet Motor With Halbach Array

This article describes the development of an exact analytical model for predicting magnetic field distribution within active parts of a dual-rotor (DR) permanent magnet (PM) synchronous machine with a Halbach array. The model is based on the accurate solution of Laplace's and Poisson's partial differential equations (PDEs) using a method of separation of variables. The model also allows the calculation of the DR machine flux linkage, back electromotive force (bEMF), and electromagnetic torque at on load and cogging torque at a no-load condition. The model can be used at the initial stage of designing a DR PM machine for the estimation of electromagnetic parameters and the optimization of machine geometry.