Capacity Optimization of lithium Battery-Flywheel Hybrid Energy Storage System

In order to enhance the output performance of energy storage and lower the cost of energy storage, this paper focuses on the energy-power hybrid energy storage system set up using a lithium battery and flywheel. Setting the cut-off frequency divides the entire power of hybrid energy storage into low frequency and high frequency components, which are then allocated to lithium batteries and flywheels, respectively, based on the Hilbert-Huang transform. The conventional economic approach, which aims for a minimal annual total cost, is enhanced. Under specific circumstances, a capacity optimization configuration model of a hybrid energy storage system is designed to limit the maximum ramp rate of lithium battery charge and discharge power, increase flywheel power, and minimize flywheel capacity. A genetic algorithm was used to resolve the capacity optimization model. Additionally, the optimal cut-off frequency is discovered after calculating the capacity optimization results for each cut-off frequency step by step. Furthermore, a real-world example of a photovoltaic power generation system attests to the usefulness of the presented approach. Finally, the output effects of single energy storage and hybrid energy storage are contrasted, and the optimization results show the advantages of the enhanced model over the conventional economic model.