دانلود رایگان مقاله انگلیسی ارزیابی یکپارچه قابلیت اطمینان و پایداری سیستم های قدرت - IEEE 2017

Abstract

This paper investigates the impacts of transient instability on power system reliability. Traditionally, composite system reliability evaluation has been performed based on steadystate estimation of load curtailments; system dynamics have often been ignored, mostly due to computational complexity. In this paper, three probabilistic transient stability indices are proposed to assess system robustness against dynamic contingencies and to account for system instability in computing reliability indices. A direct method is utilized for transient stability assessment based on computing the energy margin of the system under fault events (energy margins measure the ability of a system to withstand contingencies). Energy margins along with the probability of occurrences of the events are used to update the probabilistic transient stability indices. The dependencies of reliability and stability indices on the fault clearing time are also evaluated. This method is applied on the reduced Western Electricity Coordinating Council and the New England 39 bus test systems. The results indicate the importance of considering the effect of stability in reliability evaluation.

VI. CONCLUSION

This paper has introduced a method to assess the effect of transient instability on power system reliability. Three probabilistic transient stability indices were introduced to measure the effect of transient stability on power system reliability which are: expected transient instability, expected transient stability robustness and the expected system risk of instability. Transient stability direct methods were used in assessing system stability, determining the energy margins and updating the stability and reliability indices. Also, power system reliability indices were evaluated for the cases considering and not considering the effect of transient instability. The effect of fault clearing times on power system reliability and stability indices was also evaluated. This method was applied on the reduced WECC and the NE 39 bus systems and the results showed that the effect of transient stability should not be ignored when evaluating reliability of the system. Also, the results of the stability indices can be used to measure system robustness against disturbances and the effect of fault clearing times on reliability and stability.