Novel Temporary Frequency Support Control Strategy of Wind Turbine Generator Considering Coordination With Synchronous Generator

Frequency support provided by wind turbine generator (WTG) is important for frequency security of the power system with high proportion of wind power. A WTG initially operating at the optimal point and utilizing rotor kinetic energy for frequency support can only provide temporary frequency support, and avoiding second frequency drop is a critical issue. Synthetic inertia control, which is actually PD control, is the most widely studied control strategy, but its optimality is not well studied. In this paper, a functional optimization model of optimal control strategy for WTG temporary frequency support considering coordination with synchronous generator (SG) is built. The problem is solved with numerical method to obtain the optimal output power curves of WTGs. The optimal control strategy is then obtained with system response fitting. The coordination strategy of multiple WTGs for temporary frequency support based on the releasable rotor kinetic energy is also proposed. Practical realization of the proposed control strategy is presented. The effectiveness of the proposed control strategy is verified with real-time simulation of an actual power system with detailed electromagnetic transient model on the RT-LAB platform.