An Overview of High-efficiency Synchronous Reluctance Machines

In recent years the synchronous reluctance machines (SynRMs) have received much attention. They have some good features such as high torque density, high reliability and low cost. This paper aims to give an overview of SynRMs with particular emphasis on the history, research status and industrial application. Besides, concept and basic operating principles of such machines are also described. Moreover, some hot spots of the research on the SynRMs are introduced. Several methods to improve the average torque and reduce torque ripple of the SynRMs in the past literatures are presented including topology design and control strategies. An overview of the methods from different aspects to realize high efficiency for the SynRMs is given which contain rotor optimization, winding configuration, material improvement, control schemes and so on. Some approaches suitable for high speed application are also introduced. It can be seen that the SynRMs have broad development prospects and great potential in industrial application.