[1] Key Laboratory of Instrumentation Science and Dynamic Measurement, Ministry of Education, North University of China, Taiyuan,030051, China
[2] The School of Electrical Engineering, Zhejiang University of Water Resources and Electric Power, Hangzhou,310018, China
[3] Zhejiang-Belarus Jt. Lab. of Intelligent Equip. and Syst. for Water Conserv. and Hydropower Safety Monitoring, Zhejiang University of Water Resources and Electric Power, Hangzhou,310018, China
[4] School of Materials Science and Engineering, North University of China, Taiyuan,030051, China