Mathematical Problems in Engineering
Volume 2010 (2010), Article ID 909240, 15 pages
Research Article

Optimization Shape of Variable Capacitance Micromotor Using Differential Evolution Algorithm

1Department of Electrical Engineering, University of Kashan, Kashan 87317- 51167, Iran
2Department of Electrical Engineering, I.A.U.-Kashan Branch, Kashan 87317-51290, Iran

Received 23 May 2010; Revised 9 November 2010; Accepted 29 November 2010

Academic Editor: Mohammad Younis

Copyright © 2010 A. Ketabi and M. J. Navardi. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


A new method for optimum shape design of variable capacitance micromotor (VCM) using Differential Evolution (DE), a stochastic search algorithm, is presented. In this optimization exercise, the objective function aims to maximize torque value and minimize the torque ripple, where the geometric parameters are considered to be the variables. The optimization process is carried out using a combination of DE algorithm and FEM analysis. Fitness value is calculated by FEM analysis using COMSOL3.4, and the DE algorithm is realized by MATLAB7.4. The proposed method is applied to a VCM with 8 poles at the stator and 6 poles at the rotor. The results show that the optimized micromotor using DE algorithm had higher torque value and lower torque ripple, indicating the validity of this methodology for VCM design.