Line start synchronous motor for multi-speed applications

Abstract

This paper presents a design of Line Start Permanent Magnet (LSPM) synchronous motors capable of operating in two different synchronous speeds. The stator winding consists of two independent windings to switch the operating pole count for low and high speed applications. The rotor is especially designed to be capable of creating two different magnetic polarities (pole numbers) to match with the operating stator pole number. The proposed design combines Synchronous PM and synchronous reluctance motors and enables the motor to operate as a synchronous PM motor at high speed and synchronous reluctance motor at low speed. To verify the performance of the proposed design, the motor is analyzed in steady state and transient domain using 3-D finite element analysis (FEA).