A dynamics-constrained method for distributed frequency regulation in low-inertia power systems

An increasing number of power electronics-interfaced renewable energy sources are integrated into the power grids. Such power systems suffer from poor frequency dynamic behaviors due to the decreasing rotational inertia and governor damping, thus are vulnerable to disturbances. A widely investigated approach to improve the frequency dynamics of the system is to imitate the synchronous generator responses by power converter control. In this paper, a dynamics-constrained frequency control method is proposed to bridge the gap between frequency dynamics optimization and secondary frequency control in low-inertia power systems. An intraday optimization model is formulated for the optimal tuning of the converter control parameters with guaranteed frequency security, and a distributed model predictive controller is developed for recovering the frequency economically. Case studies demonstrate the practicability of the proposed dynamic constrained frequency regulation approach and further comparison illustrates the computational efficiency and scalability of the proposed distributed algorithm.