Storage-Based Frequency Shaping Control

With the decrease in system inertia, frequency security becomes an issue for power systems around the world. Energy storage systems (ESS), due to their excellent ramping capabilities, are considered as a natural choice for the improvement of the frequency response following major contingencies. In this paper, we propose a new strategy for energy storage –
frequency shaping control
– that allows to completely eliminate the frequency Nadir, one of the main issues in frequency security, and at the same time tune the rate of change of frequency (RoCoF) to a desired value. With Nadir eliminated, the frequency security assessment can be performed via simple algebraic calculations, as opposed to dynamic simulations for conventional control strategies. Moreover, our proposed control is also very efficient in terms of the requirements on storage peak power, requiring less (up to 40% in one of the cases) power than conventional virtual inertia approach for the same performance.