Manuscript received November 17, 2016; revised January 21, 2017; accepted February 19, 2017. Date of publication May 10, 2017; date of current version December 20, 2017. This work was supported in part by the National Natural Science Foundation of China under Grants 71331001, 71420107027, and 91547113, in part by the Science and Technology Projects of Hunan Province and Changsha City under Grants 2016WK2015 and kh1601186, and in part by the Shenzhen Municipal Science and Technology Innovation Committee under Grant GJHZ20160301165723718. Paper no. PESL-00210-2016. (Corresponding author: Junhua Zhao.) H. Yang, S. Zhang, D. Qiu, and M. Lai are with the Hunan Provincial Engineering Research Center of Electric Transportation and Smart Distribution Network, Changsha University of Science and Technology, Changsha 410114, China, and also with the School of Economics and Trade, Hunan University, Changsha 410082, China (e-mail: yhm5218@hotmail.com; zsm1016@ 126.com; qiuduoduo13@hnu.edu.cn; laimingyong@126.com).
