Hongze Dong, Chen Xie, Haoyu Zhang, University of Electronic Science and Technology of China, China; Guoqing Zhou, Guilin University of Technology, China; Zezhong zheng, University of Electronic Science and Technology of China, China; Yi Ma, Fangrong Zhou, Yunnan Power Grid Company Ltd, China; Xuefeng Yang, China Railway Eryuan Engineering Group Co., LTD, China