Application of probabilistic (N-1) security assessment technique to distribution systems with distributed generation

This paper proposes a probabilistic security assessment technique for distribution systems with distributed generation (DG). Deregulated and competitive power markets change the structure of power systems. Under the environment, distributed generation is installed to smooth operation and planning in distribution systems. However, it brings about the violation of voltage magnitudes or line flows due to the high degree of uncertainty. It is necessary to evaluate the pre-fault and the post-fault conditions and take control appropriately. In this paper, a probabilistic security assessment technique is presented to deal with case where a group of DG units is switched off. To handle the uncertainty of DG, the probabilistic power flow is employed to control the voltage magnitude with capacitor banks. Tabu search of meta-heuristics for solving a combinational optimization problem efficiently is used to optimize the capacitor banks for the post fault conditions. The proposed method is tested in a sample system.