Experimental verification of conventional phase advancement method for surface permanent magnet motor with fractional-slot concentrated windings

Abstract

The ability of permanent magnet synchronous motors to operate over a wide constant power speed ratio depends on the motor winding inductance [1]. Previous work has shown that PM motors with "sufficiently high" inductance, if operated with conventional phase advancement [4] method, can widen the CPSR significantly [3]. Compared to traditional vector control, this method is computationally very simple and does not involve any transformations. Only speed and rotor angle feedback is needed to produce the required power. It does not require any motor current or voltage feedback. Surface PM machines with distributed windings have lower phase winding inductance. Recently a method has been developed to use fractional slot concentrated windings to significantly increase the surface PM machine inductance [5]. The increased inductance method is compatible with a voltage source inverter (VSI) controlled by the sinusoidal pulse width modulation (PWM).This paper presents the analysis of the CPA controller for high inductance PM machines for traction drive application.