Minimization of cogging torque in permanent magnet motors by teeth pairingand magnet arc design using genetic algorithm

Cogging torque is often a principal source of vibration and acoustic noise in high precision spindle motor applications. In this paper, cogging torque is analytically calculated using energy method with Fourier series expansi on. It shows that cogging torque is effectively minimized by controlling ai rgap permeance function with teeth pairing design, and by controlling flux density function with magnet are design. For an optimization technique, gen etic algorithm is applied to handle trade-off effects of design parameters. Results show that the proposed method can reduce the cogging torque effect ively. (C) 2001 Elsevier Science B.V. All rights reserved.