1. State Key Laboratory of Reliability and Intelligence of Electrical Equipment, Hebei University of Technology 1 , Tianjin 300130, China
2. Key Laboratory of Electromagnetic Field and Electrical Apparatus Reliability of Hebei Province, Hebei University of Technology 2 , Tianjin 300130, China
3. Zhejiang Tengen Electric Co., Ltd. 3 , Wenzhou 325604, China
4. Bingtuan Xingxin Vocational and Technical College 4 , Xinjiang, Bazhou 841007, China