Probabilistic load flow computation using first-order second-moment method

This paper proposes a new probabilistic load flow method based on the first-order second-moment method. The proposed method aims to obtain the mean and standard deviation of load flow solution distributions considering various uncertainties in system operation. Power injection uncertainties including fluctuation of loads and unit outages are considered in the probabilistic load flow calculation. The performance of the proposed method is examined by comparing the results with those from Monte Carlo simulation using IEEE 9-bus and 118-bus test systems. A normalized accuracy and efficiency based procedure is developed for result analyses. Numerical tests demonstrate that the proposed method can obtain accurate results while reducing the computation time significantly.