Enhancing Frequency Stability for Grid Resilience Based on Effective WPPs Power Curtailment

The high penetration of renewables to a power system causes power imbalance and reduced system inertia, resulting in various frequency instability problems. Therefore, the system operator is forced to curtail a certain amount of power from several wind power plants (WPPs) and prepare for effective frequency support in case of contingency. When a large disturbance occurs, some WPPs in the curtailed control mode are able to provide the power reserve for maintaining the power balance. The other WPPs in the maximum power point tracking control mode can give the inertial response to support the frequency stability. Therefore, there is a need for a method to assist the system operator in determining the proper control mode for multiple WPPs. This article proposes an effective power curtailment method based on the new hybrid binary and continuous grey wolf optimization method for properly operating all WPPs in two control modes. This curtailment method provides key information to the system operator on operating the WPPs to provide the required amount of power curtailment and maximum frequency stability support. The effectiveness of proposed method is verified with several case studies on the practical Korea electric power system with 20 WPPs, which have a hosting capacity of 10.6 GW.