On the Frequency Control of Energy Storages: A Unified Analysis and Design

In the pursuit of carbon neutrality and sustainability, great concerns on frequency security arise from the everincreasing penetration of new energy generation (NEG). Due to its fast response and strong controllability, energy storage (ES) has been recognized as an appealing resource to improve the frequency performance of power systems with high-penetration NEG integrated. However, how to coordinate the frequency control of ES with conventional primary frequency regulation (PFR) is still underdeveloped. In this paper, we propose a unified frequency control with energy feedback control (UFC) that unifies various kinds of widely-used frequency controls. The coordination between the ES control and conventional PFR can be readily achieved by adjusting the control parameters. Therefore, it provides a unified framework to quantitatively analyze and optimally design the frequency control of ESs. Simulations on the simplified Central China Power Grid show that the proposed controller can achieve better performance with less energy consumption (more than 20%) than the state-of-the-art control strategies.