Switched Reluctance Motor Design for a Forklift Traction Application

This paper presents the design of a switched reluctance motor (SRM) for the traction motor of a forklift application. Design constraints and input parameters are defined according to the specifications of a forklift traction motor. Three-phase induction machines are commonly used for forklift propulsion systems. Several SRM configurations with higher number of rotor than stator poles are designed in order to compare their characteristics and capabilities. These configurations are 12/16, 12/20 and 18/24, and they are compared in terms of average torque, weight, RMS torque ripple, efficiency and temperature rise. Initial designs are obtained by basic analytical sizing equations. Optimization of initial designs is performed using combined analytical-FEA approach and genetic algorithm control optimization. Optimization goal is to achieve the design with the lowest volume and mass to increase torque density (torque/volume) and specific torque (torque/mass). The results show that 12/16 SRM is a suitable configuration for the forklift propulsion application due to its higher torque density.