Performance and design of a novel single-phase hybrid switched reluctance motor for hammer breaker application

In this paper, a novel single-phase hybrid switched reluctance motor (HSRM) is proposed for hammer breaker application. The hammer breaker requires only unidirectional rotation and high speed operation without torque dead-zone. To satisfy the requirements, the rotor of the 4/4poles proposed SRM is designed with wider rotor pole arc and non-uniform air-gap is applied on the rotor. This motor has a simple structure and produces low torque ripple. Permanent magnets (PM) are placed at parking positions for self-start and to create positive cogging torque in the torque dead-zones. Compared with conventional single-phase switched reluctance motor, HSRM has an increased torque density and relatively low torque ripple, along with a simpler structure. To verify effectiveness, finite element method (FEM) is employed to analyze the performance of the proposed structure. Comparison between the proposed motor and the existing motor drive system for hammer breaker application is demonstrated. To verify the proposed design, a prototype motor is manufactured and tested. The experimental results are presented.