SYNCHRONOUS MOTORS WITHOUT ROTOR WINDINGS CONTROLLED BY FREQUENCY CONVERTERS FOR ITS APPLICATION IN ELECTRIC VEHICLES

Abstract

Electric motors required by electric vehicles must be effective, efficient and economical. The accelerated development of power electronics and speed control with frequency converters allows the use of adjustable speed systems within a wide range. From a study of specialized literature, different types of synchronous motors without rotor windings were compared in this paper for these vehicles. Comparative assessments were made, based on momentum and power, losses and efficiency, power factor, costs and other characteristics of synchronous permanent-magnet motors,synchronous reluctance motors and synchronous reluctance motors assisted by permanent magnets. This allowed assessing the best technical-economic variant. It was shown that the last one, using ferrite magnets, ensures the lowest cost, with high absolute values and density of momentum and power, high efficiency and high power factor.