1. Drive and Control Systems Department, Mitsubishi Electric Corporation, Amagasaki, Hyogo 661-8661, Japan
2. Space Sub-Systems Electrical Engineering Department, Mitsubishi Electric Corporation, Kamakura, Kanagawa 247-8520, Japan
3. Department of Advanced Energy Engineering Science, Kyushu University, Kasuga, Fukuoka 816-8580, Japan
4. Department of Aerospace Engineering, Tokyo Metropolitan University, Hino, Tokyo 191-0065, Japan