In order to estimate the static voltage stability for AC/DC hybrid transmission system,a probabilistic method taking account of the stochastic influence of the changes of load and the faults of generating and transmission equipment was proposed.The non-sequential Monte Carlo method was carried out with the samples of load state and generating and transmission equipment’s state.And the load state was obtained by the methods of load clustering and multivariate normal sampling.Furthermore,theL-index calculated with quasi steady state model of DC was used to assess the system voltage stability and the local voltage stability with an amount of random samples.Finally,the system IEEE-RTS was applied to demonstrate the validity.By the analysis of the frequency,probability distribution and sensitivity of the static voltage among the operation modes of DC bipolar,monopole and the original AC system,the results showed that the DC transmission ratio plays great role in static voltage stability which would be decreased when the ratio increases.
