Research on Control Strategy of Independent Micro-grid with Photovoltaic Energy Storage

Regarding the volatility and uncertainties in the operation of independent microgrid with photovoltaic energy storage, a control strategy based on sliding mode is proposed to enhance the robustness against various disturbances and improve the system dynamic performance. In order to effectively reduce the adverse effect of external solar irradiation, a non-singular fast terminal sliding mode control (NFTSMC) based on front DC/DC converter is proposed, in which incremental conductance method (InC) is implemented , to boost the maximum power point tracking (MPPT) performance by means of adjusting the photovoltaic output voltage tracking reference voltage. In order to alleviate the adverse effect of load change on the system performance, a control scheme based on sliding mode control of full bridge inverter is proposed to achieve low steady state error and rapid dynamic response. Furthermore, in order to maintain the voltage stability of the DC bus, the traditional dual-circuit PI control scheme is used to realize the bidirectional DC/DC converter to ensure the power balance of the system. Finally, simulation tests are carried out in Matlab/simulink environment to verify the effectiveness of the control strategy.