Analytical calculation of air-gap magnetic field in permanent magnet motor with tile-form poles

By the equivalent surface current method, the paper get the analytical algorithms of air-gap magnetic field in PM (permanent magnet) motor, which is with tile-form poles and magnetized by different modes. From the results, an ideal flat-roofed wave of air-gap magnetic field is produced under radial magnetization; while, an arc-roofed wave produced under parallel magnetization. Because it's difficult to get magnets under strict radial magnetization in actual process, this paper designs a new shape of poles, which can produce a relative ideal flat-roofed wave under parallel magnetization. Comparing the result of two-dimensional finite element method, it demonstrates the correctness and validity of the discussed analytic method.