1. School of Control Science and Engineering, Shandong Univ., 73 Jingshi Road, Jinan, Shandong, 250061, CN.
2. School of Control Science and Engineering, Shandong Univ., 73 Jingshi Road, Jinan, Shandong, 250061, CN (Corresponding author), e-mail: jiangqi@sdu.edu.cn
3. School of Energy and Power Engineering, Shandong Univ., 73 Jingshi Road, Jinan, Shandong, 250061, CN.