Equivalent Method For Power System Reliability Evaluation

With the rapid development of power industry, power network has been changed into large interconnected power system. The reliability of power supply has been enhanced. But power system reliability evaluation has been much more complex, and often costs a lot of computation time.This paper introduces the equivalent method for power system reliability evaluation. In this approach, the general power system is divided into two areas, the interconnected area and the area of interest. The interconnected area is replaced by a equivalent generation and a equivalent load, and these two values can be obtained by network flow solution. Then, the whole power system is simplified, and the computation time of reliability evaluation is reduced.The interconnected power system studied in this paper contains two IEEE RTS-24 test systems. Reliability evaluation of this system is performed by two approaches, the method without equivalent and the equivalent method. The results of reliability evaluation indicates that the reliability indices obtained by the equivalent method is acceptable, and the computation time is greatly reduced. So, this method can be very practical and effective for reliability evaluation of large interconnected power systems.