Probabilistic voltage stability analysis of wind farm integrated power grid

Because of the environment issue and energy crisis, wind power is experiencing a rapid development in the world. Unfortunately it also brings increasing voltage stability problems for the reason that its output is stochastic and intermittent. This paper addresses power flow models of fix speed induction generators (FSIG) and doubly-fed induction generators (DFIG) which involve generator´s slip, and applies them into probabilistic power flow computation. A novel voltage stability sensitivity index considering wind generator´s slip is proposed subsequently, which takes into account the wind power´s randomness. IEEE 39 bus-system including FSIG and DFIG separately is taken as testing example to verify the effectiveness of the proposed models and voltage stability index, then the paper compares the impacts of two different induction generators on system voltage stability.