1. J. Lou, Q.M. Li, Q.S. Sun, W.D. Liu, and J.L. Qian: Proceedings of the CSEE Vol. 25(16), 2006, pp.23-29.
2. E.Y. Dong, B. Li and J.Y. Zou: High Voltage Apparatus Vol. 43(2), 2005, pp.125-126.
3. Z.J. Wang, J.J. He, X.G. Yin, K. Bian and H.M. Zhang: Proceeding of the first Conference of Intelligent Electrical equipment(2007), pp.124-131.
4. T. Takeuchi, K. Koyama and M. Tsukima: Electrical Engineering in Japan Vol. 152(4), 2005, pp.8-16.
5. M. Tsukima, T. Takeuchi, K. Koyama and H. Yoshiyasu: Electrical Engineering in Japan Vol. 163(1), 2008, pp.34-39.