Application Of Probabilistic Load Flow Calculation In The Static Security Analysis

Static security analysis is a fundamental problem in power system operation and planning.For a long time,as the basis of static security analysis,the power flow calculation has always used certain methods.However,in the actual operation of system, the network configuration and loads are uncertain.The probabilistic load flow considering uncertainties of generation and loads could give the probabilistic distributions of the nodal voltages and the line flows,by only once calculation.This paper proposed a static security analysis method based on probabilistic load flow.Compensation method was used to obtain the linear relationship between power injections and line flows,when considering branch outages.Then cumulants and Gram-Charlier expansion can be used to compute the probabilistic distributions of the transmission line flows.According to the list of expected accidents,a case study of WSCC 179-node system was calculated in this paper and the results show that the proposed method has much higher speed and a high degree of accuracy.