Performance Comparison of Short-Pitched and Fully Pitched Switched Reluctance Machines Over Wide Speed Operations

Abstract

This paper presents a comprehensive comparison of switched reluctance machines (SRMs) with short-pitched and fully pitched windings for the same machine geometry. An SRM designed for off-road vehicles with short-pitched windings is rewound with full-pitched windings and the two winding structures are compared. The two different winding configurations were evaluated with unipolar excitation at the same bus voltage level for the driver. The machines are compared with respect to their electromagnetic behavior, operating range, torque per ampere, and efficiency. The effect of winding configuration and the number of turns are investigated as they determine the torque speed characteristics of SRMs. The comparison in this paper would better guide designers on what type of winding configuration would best suit their applications. The comparison is conducted with the aid of finite element analysis. A 50 kW prototype SRM is used for experimental validation of the short-pitched and fully pitched SRMs.