Stator and Rotor Pole Shaping for Bidirectional Starting of Two-Phase Switched Reluctance Motor

Single and two-phase switched reluctance motors are particularly suitable for low cost, high volume applications such as washing machines, fans, pumps etc. Two-phase motors are preferred due to improved performance such as reduced torque ripple. Still, two-phase motors have starting problems due to torque dead zones. While solutions address unidirectional on-load starting, bidirectional starting still remains a challenge. In this work, conventional two-phase switched reluctance motor is analyzed to highlight design constraints leading to starting limitations, particularly bidirectional. To address this, magnetic design of 8/4 switched reluctance motor is altered through stator and rotor pole shaping. The proposed modifications in the magnetic structure lead to bidirectional high starting torque. Simulation results are presented to validate the proposed design. Design changes to alter the starting torque to requirements are also introduced.