COMBINED FINITE ELEMENT AND ANALYTICAL METHODS FOR ROTOR DESIGN OF PERMANENT MAGNET SYNCHRONOUS MOTORS

ABSTRACT

While design procedures for conventional induction and synchronous machines are now mature and constrained by frame sizes and standards, there are opportunities to use modem CAD techniques to exploit the unique capabilities and characteristics of permanent magnet synchronous motors (PMSM). This paper presents a design methodology involving the use of an analytical model based on generalized machine theory, complemented by finite element analysis. The synergistic interaction of these two methods allows an engineer to design a PMSM to specific requirements with confidence. The effects of machine airgap and of the span angle and thickness of the permanent magnets are evaluated. A set of design specifications and a goodness function are established to select the preferred rotor geometry for a 30 hp prototype permanent magnet synchronous motor.