Expected security constrained reactive power planning
The adequate reactive power resources are expected to maintain system integrity under both normal and post contingency operations. Nowadays, the power systems are leading to high-risk operating points, hence, the number of probable contingencies, which should be considered in security constrained reactive power planning (SCRPP), has widely increased. However, considering a large number of contingencies in SCRPP is not practically possible. This study presents an index named expected violation index to consider numerous contingencies in SCRPP. At first, a multi-objective algorithm for the proposed expected SCRPP approach is presented. This novel algorithm uses the probability of each contingency to invest on them more efficiently. Next, it presents a method for selecting candidate buses to install reactive power resources. Then, the effectiveness of the proposed method is analysed using a multi-objective particle swarm optimisation algorithm on IEEE 30-bus test system. Finally, a reliability-based quantitative method is presented for selecting among final Pareto optimal solution. Using the proposed method, the system designers are capable to consider a large number of contingencies in their SCRPPs, to invest more purposefully in reactive power equipment, and to select their most appropriate option among different feasible choices in the optimal Pareto solution.