Stochastic Computation of Power System Security Level

Power network security can be disturbed in situations of high penetration of dispersed generation (DG). Such situations lead to bottlenecks in the power network, which is especially observed in the German power network. These bottlenecks can either be eliminated by network extensions or by the use of generation response (GR). The GR, realized in Germany through the so called network security management (NSM), restricts the generation power in cases of network parameter violations such as excessive thermal currents. In this paper, first the security level indices will be defined. Because load, wind- and sun power have a highly stochastic nature, stochastic simulation in the form of a sequential Monte Carlo simulation (MCS) is employed to calculate those indices. The CIGRE distribution system benchmark is chosen for testing the simulations. Both, an aggregated and the complete distribution system were used to calculate the occurrence of network parameter violations. The results will be compared and discussed. This paper finishes with a discussion and demonstration about the advantage of implementing the developed methodology in a professional power system simulator.