Probabilistic Power Flow Calculation Using Sigma-Point Transform Algorithm

This paper introduces sigma-point transform algorithm for the probabilistic power flow problem. It is assumed that the uncertainties of bus power injections and network parameters can be estimated or measured. Using the sigma-point transform algorithm can accurately estimate the corresponding uncertainty in the power flow solution. Through series expansion of the traditional non-linear power flow equations, formulae of the true mean and covariance of the stochastic variable resulting from the non-linear transformation are obtained. In this paper it is proved that the transform method can approximate the true mean and covariance better than the linearization method does. Performance of the sigma-point transform algorithm agrees very close with the MCS results using IEEE 14 bus test systems.