Probabilistic approaches to power system security assessment

The occurrence of contingencies in power systems and their impacts are non-deterministic, justifying probabilistic approaches to power system security assessment. In this work, a probabilistic methodology to assess the security of electrical power systems is applied. The IEEE 39 and 118 bus systems are used as case studies. The distributions of security indices such as Expected Demand not Served are derived by performing nonsequential Monte Carlo simulations and by considering remedial actions such as load shedding and line tripping. In order to account for the uncertainty in the knowledge of their values, various failure probabilities for the individual elements of the power system are considered. Results are discussed in terms of evaluating both the method applied as well as the security of the examined systems.