Effect of Wind Power Integration on the Self-Excitation Risks in Weak Interconnection Power Grid

Abstract

To explore the self-excitation risks in weak interconnection power grid from the wind power flow, a vector control model of variable speed wind turbine based on doubly fed induction generator (DFIG) is established using electromagnetic transient simulation software PSCAD/ EMTDC. Start from the basic circuit model, the self-excitation phenomenon is analyzed with wind power integration. Simulation results show that the effect of wind power integration on the self-excitation risk is mainly determined by DFIG’s operation method, and wind power integration will affect self-excitation engineering judgment method at the same time. When DFIG works in phase late operation or has no reactive power exchange with the main power grid, cutting the wind turbine after broken thread quickly can restrain the worsening trend to a certain extent. However cutting the wind turbine after broken thread when DFIG works in phase advance operation may cause a voltage jump of the hydraulic synchronous generator in parallel with the wind turbine.