Optimization of hybrid energy storage based on micro grid optical storage and DC in certain regions

Abstract

It is of great significance to maintain the stability of DC micro grid bus voltage and improve the economic benefits of the micro grid system. A hybrid energy storage form of flywheel and battery is proposed as the energy storage form of the DC micro grid system of the optical storage charging station. The flywheel is used to smooth high-frequency power fluctuation and part of low-frequency power, and the battery is used to balance the reference power to maintain smooth and stable bus voltage. The hierarchical coordinated control strategy of DC bus is designed to achieve the coordinated control of photovoltaic power generation, electric vehicle charging and discharging, and load power demand in the microgrid system. According to the different working conditions of island operation and grid connected operation, the proposed control strategy is simulated and analyzed on the Matlab/Simulink software platform. The simulation results show that under all working conditions, the proposed control strategy can effectively switch the DC bus voltage between different voltage layers, maintain the DC bus voltage balance of the DC microgrid system of the optical storage charging station, and realize the flexible and reliable operation of the entire system. Therefore, the control strategy is feasible and effective.