1. School of Electrical Engineering and Automation Anhui University Hefei, 230601 China
2. School of Electrical and Information Engineering Jiangsu University Zhenjiang, 212013 China
3. Department of Electrical Engineering, Mechatronics Section CINVESTAV‐IPN Mexico City, 07360 Mexico
4. Department of Electrical and Computer Science Cleveland State University Cleveland Ohio 44115 USA