Electromagnetic force density calculation in surface‐mounted PM synchronous machine with rotor eccentricity by an equivalent transformation method

Abstract

An equivalent transformation method is proposed to calculate the electromagnetic force density of surface-mounted permanent magnet (PM) synchronous machine with static and dynamic eccentricities. It hypothetically transforms the original, eccentric machine into a concentric one with redistributed PM remanence and current density according to equivalent transformation principle. On the basis of the magnetic field of the concentric machine obtained by the subdomain method, the air-gap flux density of the eccentric machine is then achieved. Finally, the electromagnetic force density is predicted by the air-gap field based on Maxwell stress tensor method and analysed by the two-dimensional Fourier transform. The effectiveness of this method is verified on both static and dynamic eccentricities conditions by the finite-element method and experiment.