The Study Of Algorithms For Power System Reliability Evaluation Based On Monte Carlo Simulation

With the development of economy, the stability of the power supply receives great attention. In order to ensure the safe and stable operation of the power system, power system reliability evaluation is becoming more and more important. A general description of the development of power system reliability evaluation is given in this paper firstly. The following chapters illuminate the methods of setting up elements outage models in detail, including independent outage, planning outage and common mode outage, etc. Introduction of common power system reliability evaluation method is also given in this paper, such as analytical method, fault tree analysis, Monte Carlo method. After comparing the differences between those methods, the system state analysis process is discussed and the principle of optimal load-shedding is presented.To avoid commonly used reliability evaluation method’s low efficiency and degeneration, a stratified uniform sampling method, which combines the advantages of stratified sampling and importance sampling, is proposed here. The proposed method can avoid the complexity of constructing the importance sampling function, and reduce the experiment times by stratified sampling. Without sampling on zero fault state, the proposed method can be applied in the high reliability system efficiently.By combining the accuracy of analytic method and the high efficiency of simulation method, an efficient power system reliability evaluation algorithm was presented, which divides the system fault states into sorting subset and sampling subset to maximize the computational efficiency. With improved fast sorting technique, the algorithm analyzes the fault states with biggish occurrence probability firstly. Then, stratified uniform sampling method is adopted to sample the remained system fault states, which accelerates the convergence and avoids efficiency degradation. Compared with Monte Carlo simulation and importance sampling method, the results of the IEEE-RTS79test system and revised system show that the proposed algorithm is correct and effective in power system reliability.