Battery-storage-centered Microgrids: Modelling and Simulation Demonstration.

The modeling and control of microgrids with energy storage systems (ESSs) can effectively deal with the increasing penetration of renewable energy resources with high uncertainty. In this paper, the battery model is proposed, and the energy storage system is combined with the battery control strategy to mitigate the fluctuation of renewable energy. Firstly, this paper selected the topological structure of Thevenin and the parameters of the model for the lithium-ion battery are identified by the open circuit voltage (OCV) test and HPPC (Hybrid Pulse Power Characteristic). The ampere-hour integral method is used to estimate the state of battery charge. Secondly, Simscope equivalent circuit and transfer function are used to model. The three-phase voltage source converter is selected as the grid-connected control system (PCS) of the energy storage. Grid-connected PQ control and isolated island V/f control are selected as the control strategy of PCS. Finally, a microgrid simulation model including turbine and photovoltaic is established to simulate the microgrid operation process. The experimental simulation results demonstrate that during the microgrid islanding operation, the turbine and PV output varies, but the three-phase voltage frequency and magnitude at the parallel grid point remain stable and effectively validate the renewable energy output fluctuation stabilization ability of energy storage in microgrid.