Reliability Evaluation Of Composite Systems Considering Voltage Stability Problems

Voltage stability has become one of rhe most important and urgent problems in modern bulk power supply systems because serious failures have been caused by this phenomenon.On the other hand,voltage stability assessment isn't considered in composite system reliability evaluation for a long time.This paper considers voltage stability, and evaluates adequacy indices of composite system based on Monte-Carlo simulation tegether with analytic method. For reducing the time for calculating,the concepts of relevant regions and regulative regions are proposed based on the concept of central relaxation and used to judge the relations between the outage components,which makes it efficient to screen the possible outages.This paper considers voltage stability when analysing load curtailment. Analyse voltage stability by static equivalent method, and calculate the maximum transmitting power, with the maximun transmitting power calculated by thermally stable ,we can get the accurate maximum transmitting power for every electric transmission line. Then calculate load curtailment, and evaluate reliability indices of the system.In the end,test of a 24-bus IEEE RTS shows that the approach developed is valid and available.