A New Method for Minimizing Cogging Torque in Permanent Magnet Machines Using Genetic Algorithm

Abstract

Cogging torque is one of the main reasons which cause ripple in motor's speed and torque. So the reduction of cogging torque must be considered in the design of permanent magnet machines. This paper presents a new method for cogging torque minimization by optimizing pole-arcs combined with varying the thickness in magnets. With the combination of different pole-arcs of each PM slice to achieve the minimum cogging torque while without being harmful to the average torque. Thus, optimize the offset value which varies the thickness of magnets to further reduce the amplitude of cogging torque. In this paper, it used genetic algorithm (GA) to optimize pole-arcs and magnet offset on the basis of Finite Element Method (FEM).