Voltage security assessment with high penetration levels of utility-scale doubly fed induction generator wind plants

The interconnection requirements set forth by FERC in order 661-A mandate the operation of wind plants within a power factor range of 0.95 leading/lagging. This operation drastically underutilized the reactive output of doubly fed wind turbines (DFIG). This work discusses the impact of utilizing the capability curve of DFIG based wind plants on steady state and dynamic power system operation. A test system is used to demonstrate that committing the full reactive capability of a DFIG park can increase system penetration levels. This additional reactive support was also found to improve post fault voltage profiles by damping oscillations and preventing overshoots immediately after being subjected to a disturbance. The utilization of extended reactive limits in voltage control may prevent system collapse.