1. State Key Laboratory of Electrical Insulation and Power Equipment, Center of Nanomaterials for Renewable Energy (CNRE), School of Electrical Engineering, Xi’an Jiaotong University, Xi’an 710049, China
2. Xi’an Key Laboratory of Electrical Equipment Condition Monitoring and Power Supply Security, College of Electrical and Control Engineering, Xi’an University of Science and Technology, Xi’an 710054, China
3. Frontier Institute of Science and Technology, Xi’an Jiaotong University, Xi’an 710054, China
4. Key Laboratory for Physical Electronics and Devices of the Ministry of Education & Shaanxi Key Lab of Information Photonic Technique, School of Electronic Science and Engineering, Faculty of Electronic and Information Engineering, Xi’an Jiaotong University, Xi’an 710049, China