This study assesses the ability of a grid energy storage device to perform both peak shaving and frequency regulation. It presents a grid energy storage model using a modelled VRFB storage device and develops a controller to provide a net power output, enabling the system to continuously perform these functions.
2.2. Dynamic Regulation Dynamic regulation is a bidirectional frequency control strategy. The battery energy storage system actively adjusts its output power within 1 s based on the grid frequency state, instantaneously compensating for active power to achieve grid frequency stability.
According to the generator output curve and energy storage output curve, the peak regulating effect of energy storage after parameter optimization is better than that without parameter optimization.
The connection of energy storage devices to the power grid can not only effectively utilize the power equipment, reduce the power supply cost, but also promote the application of new energy, improve the stability of the system operation, reduce the peak–valley difference of the power grid, and play an important role in the power system.
The energy of the battery energy storage system under static regulation strategy is maximum at 25.83 MJ for the peak load scenario. Therefore, the virtual inertia strategy and the static regulation strategy have a better limiting capability for RoCoF compared to dReg 0.25 and dReg 0.5.
Peak shaving and load leveling refer to processes during which the battery energy storage system stores electrical energy (charging process) under low electrical load and releases the stored electrical energy (discharging process) under high electrical load .