Abstract— The power grid containing wind farms is analyzed by
AC probabilistic load flow. By using the method of the
combination concept of Cumulants and Gram-Charlier series
expansion theory, the DC probabilistic model is extended into AC
probabilistic model, in which a three-parameter Weibull
distribution is adopted to describe the random variation of wind
speed, meanwhile the asynchronous wind turbine generator is
treated as PQ node, then a probabilistic model of wind turbine
generator is built. Based on the built model the calculation of
IEEE 118-bus system is carried out, and then the probabilistic
distributions of nodal voltages as well as the probabilistic
distribution of branch load flow are obtained. The variation of
nodal voltages and branch load flow before and after the
connection of wind farms with power grid is compared.