Theoretical and Experimental Investigations on a Solid-Rotor Switched Reluctance Motor to Enhance Torque Output Through Stator Winding Reconnection

In solid-rotor Switched Reluctance Machine (SRM), the rotor is carved out of a solid magnetic material. Solid-rotor is well suited in applications involving high speed, high shaft temperatures, and highly corrosive environments. Due to the lack of laminations on the rotor, the eddy currents and hysteresis losses can reduce the torque output of the SRM. Hence a theoretical and experimental study is presented in this paper, explaining the possibility of improvement of torque by allowing the mutual flux linkage variation. This can be achieved through changing terminal connections of a conventional winding of an SRM. For the given dimensions of the machine, 2D Finite Element Analysis (FEA) is used to obtain the nature of self and mutual inductance of the mutually coupled winding. A comparison of average torque and radial forces is presented through FEA for balanced bi-polar excitation of mutually coupled winding with uni-polar excitation of conventional winding. An experimental procedure for obtaining self and mutual flux linkages of a mutually coupled solid-rotor SRM at a very low frequency of 0.5 Hz is discussed. The experimental inductance profile and flux linkages obtained are compared using 2D and 3D FE analysis.