ANATOMY OF POWER-SYSTEM DISTURBANCES - IMPORTANCE SAMPLING

The study of North American Reliability Council reports indicate that protection systems frequently play a role in the sequence of events th at lead to power system disturbances. While it is generally believed t hat the self-monitoring and self-checking feature of digital relays wi ll reduce the probability of such relay involvement, there has been no qualitative evaluation of the effect of such a reduction. The techniq ue of ''importance sampling'' is used to make this problem more manage able. Using the New England 39-bus system, it is shown that reducing p robability of relay involvement has a significant influence on overall system reliability. (C) 1997 Elsevier Science Ltd.