Analytic calculation of magnetic field and force in Halbach permanent magnet linear motor

The calculating formula of magnetic field produced by single permanent magnet (PM) is deduced based on equivalent current model and magnetic field of Halbach PM array is also given. Secondly, A model of linear synchronous motor whose stator is air-cored coil and mover is Halbach PM array is designed. Then, air-gap magnetic field and force are calculated by both the above formula and commercial electromagnetic simulation software MaxWell. The error between the two methods is less than 2 percent. Compared with the software, the formula presented in the paper is accurate and timesaving which can be used as a fast calculating method for designing and validating linear synchronous motor with Halbach PM array.