1. The Key Laboratory of Control of Power Transmission and Conversion Shanghai Jiaotong University,Shanghai,China
2. School of Electronic and Electrical Engineering Shanghai University of Engineering Science,Shanghai,China
3. Foshan Power Supply Bureau of Guangdong Power Grid Co., Ltd,Shanghai,Jiaotong University Fo Shan,China
4. School of Electrical Engineering Inner Mongolia University of Technology,Hohhot,China