Research on Power Coordination Control Strategy of Photovoltaic Grid-connected System with Hybrid Energy Storage

In view of the strong randomness and large fluctuation of power output for photovoltaic power generation system, a power coordination control strategy for PV-super capacitor-battery-electrolyzer hybrid power generation system is presented in this paper. The mathematical models of photovoltaic, super capacitor, battery and electrolyzer are established, and a hybrid system structure that gathers each unit of the system on the DC bus through the converter is built. The control strategy takes into account the state of charge (SOC) of both the super capacitor and the battery, the voltage stability of the DC bus is maintained and the internet power is smoothed through the coordinated control on the output of each unit under different conditions of system, in the premise of DC microgrid active power balance, which improves the utilization rate of photovoltaic. The correctness of the proposed model and the validity of the control strategy are verified by PSCAD/EMTDC software simulations.