Analysis of “Importance sampling” in electric power system security

Power system security has become one of the most important issues in power system operation due to intensive use of transmission network and it is strongly tied with contingency analysis. However with the introduction of more variable generation sources such as wind power and due to fast changing loads power system security analysis will also have to incorporate sudden changes in injected powers that are not due to generation outages. The probability of failure induced by changes in grid state is evaluated by the Monte Carlo simulation method. A comparison to crude Monte Carlo (CMC) and Importance sampling (IS) is performed for standard IEEE-33 bus system. Importance sampling method indicates a major increase in simulation efficiency by reducing number of samples.