For the defects of deterministic flow calculation method does not accurately describe the transmission network random nature, researched on that multiple random failures on the influence of transmission network voltage and load flow distribution First of all, the method of combinatorial analysis is used to prove several properties of the units of generator failure, load fluctuations and disconnection fault. Secondly, application the stochastic load flow analysis method of semi-invariant and Gram-Charlier series expansion, under the influence of multiple uncertainties striked each node voltages and the trend of the probability distribution of each branch,. Finally, it was obtained that under different conditions the more limited probability of node voltages and the overload probability of branch flows, and made evaluation of the influence degree that the multiple uncertainties on the transmission network voltage and branch power. The results provided a important valuable reference for the planning and operation of the transmission network.
