Improved three-point estimation method for probabilistic power flow calculation

Abstract

The large-scale grid connection of new energy power generation has brought uncertainty to the power system due to its own intermittency. At present, the three-point estimation method is one of the commonly used methods of probabilistic power flow calculation for power system planning, operation and control of uncertain quantities. However, this method has the problem of insufficient tail accuracy. For this reason, this paper proposes to add a set of normal distribution tail points and combine the three-point estimation method to calculate, use Nataf transform and Cholesky decomposition to process the correlation input variables, and use Cornish- Fisher series fit to get the probability distribution function. The system of IEEE14 node, IEEE30 node and IEEE57 node was tested, and the results verified the correctness of the improved three-point estimation method of probability power flow algorithm.