1. Department of Electronic and Electrical Engineering, University of Sheffield, Sheffield, U.K.
2. Motor and Electromagnetic Engineering, Midea Group Industrial Technology Research Institute, Foshan, China
3. Electrical Machines and Control Systems Research and Development Center, Guangdong Meizhi Compressor Company Ltd., Foshan, China
4. Guangdong Meizhi Compressor Company Ltd., Foshan, China