In the planning and operation of current power system

a number of uncertainties have been brought into the power system because of electric components’ operating state

data collection and multipoint access of renewable energy

etc. Of these uncertainties

the most prominent is the uncertain power flow

which will fluctuate when stochastic fluctuation is generated by the nodes’ injected power. To solve this problem

an improved multi-point estimate method of solving uncertain power flow based on Nataf transformation and Gauss-Hermite integration is proposed. The basic idea is to change the uncertain problem of power flow into a response function with multiple random variables. Firstly

the multi-estimate points in the standard normal space and the relevant weight can be obtained according to Gauss-Hermite integration. Secondly

the estimate points in the original variable space can be obtained by Nataf transformation. With the estimate points in the original variable space and the relevant weight

the node voltage amplitude and phase angle

the branch active and reactive power can be easily calculated statistically. Simulations show that the results obtained by the improved multi-point estimate method have a higher precision compared with the traditional point estimate method. In addition

the precision of the calculation results will be improved if the number of selected estimate points is increased. This work is supported by National High Technology Research and Development Program of China (863 Program) (No. 2011AA05A105) and State Grid Jiangsu Electric Power Company (No. GHJS1400036).