1. College of Electrical Engineering and Automation, Fuzhou University, Fuzhou, Fujian 350108, China
2. School of Electrical and Automation Engineering, Hefei University of Technology, Hefei 230009, China
3. Engineering Laboratory of Power Equipment Reliability in Complicated Coastal Environments, Shenzhen International Graduate School (SIGS), Tsinghua University, Shenzhen 518055, China
4. Department of Engineering, The University of Exeter, Streatham Campus, Northcote House, Exeter EX4 4QJ, U.K.
5. State Key Laboratory of Electrical Insulation and Power Equipment, Xi’an Jiaotong University, Xi’an, Shaanxi 710049, China