Transient stability assessment for power system with wind farm considering the stochasticity

The increasing penetration of wind power has significantly affected the transient stability of power grids. In this article, considering the energy absorbed in inductive components of DFIG and the wind speed fluctuating, a new transient energy function model is proposed to describe the transient stability of power system with wind farm integrated. First, a stochastic differential equation is formed by considering the stochastic fluctuation of wind speed. Based on this equation, the transient energy function model considering the characteristic of DFIG is then established by utilizing the equivalent circuit of the dq axis of DFIG. The energy absorbed by inductor has been included in the formulation. Furthermore, the established energy function is transformed into a stochastic process by correlating the stochastic wind speed model. Finally, the transient stability margin is calculated by the PEBS method. To validate the proposed method, case studies are conducted on the IEEE 39 bus system integrated with DFIG. The influence of different capacities of wind power penetration on the transient stability is compared and analyzed. The simulation results demonstrate the feasibility and effectiveness of the proposed method.