Application Study On Vulnerability Assessment In Power System Security Defense System

Because o f v arious kinds of inner and outer factors P ower system w ill b ecome relatively vulnerability and cause cascading outages. Power system vulnerability assessment studied in this paper is to assess cascading outage's happening probability. The vulnerability value defined here is the probability value that the failure can cause cascading outages. In this paper we f irstly analyze t he typical c ascading o utages t o s how the necessity t o b uild t he security defense system and explain it's function. Secondly we carry on practical division to the operational state of the system, thus to provide the standard of judging our studying target - cascading outages. Considering of power system size and many kinds of uncertainty, we draw lessons from dependability project, select for use Monte Carlo simulation method to assess vulnerability, especial in transmission system -the failure which happened in the transmission system may cause cascading outage. The analytic produce involves simulations of every component's state in transmission system, simulations of the detailed failure situation. We select classical analytic method and direct current power flow method to calculate t he d ynamic and s tatic loads losing. O verall f rame a nd c alculation p rocedure o f vulnerability assessment and a demonstration with the little power system about two main modules have provided in the paper.