Design of a disc permanent magnet linear synchronous machine for electric vehicle application

This paper presents a new disc permanent magnet linear synchronous machine (DPMLSM) for application to electric vehicles. The windings and permanent magnets of the proposed machine are well-arranged to fulfil requirements of large torque density and high efficiency for electric vehicle application. Electric vehicles equipped with the proposed DPMLSM can be driven directly without any gear-ratio device and the speed has a very wide operating range so that transmission losses can be reduced dramatically. Due to its inherent characteristics of DPMLSM, even under low speed operation conditions the machine is controlled smoothly and the torque ripple is very small with a simple six-step inverter control technique. Experimental results are presented to demonstrate the performance and adequacy of the proposed scheme