Field Analysis for a High-Power, High-Speed Permanent Magnet Synchronous Machine of the Disc Construction Type

ABSTRACT The disc construction of the synchronous machine is advantageous for applications where low loss and high power density are desired. These requirements are met by permanent magnet machines designed to operate at high speed and frequencies up to 600 Hz. The stator teeth are made with a compacted iron powder-synthetic resin mixture using powder metallurgy and thus have low iron losses at this frequency level. This mixture has a lower magnetic permeability than steel sheets. This paper presents an analytical field calculation method which considers the finite permeability of the stator iron and the non-homogenity of the field along the magnet height caused by the magnet leakage. The analysis is given for a machine configuration with two rotors. This topic is still the object of extensive technological and theoretical studies. The method presented can be modified to apply to other constructional forms of permanent magnet machines. The derived expressions for the field are used to investigate the influence of some design parameters