8Doorman G L, Uhlen L, Kjolle G H, et al. Vulnerability analysis of the Nordic power system[J]. IEEE Trans on Power Systems, 2006, 21(1): 402-410.
9EI-Sharkawi M A. Vulnerability assessment and control of power system[C]. IEEE/PES Transmission and Distribution Conference and Exhibition, Yokohama, Japan, 2002.