Research on Inertial Optimization Control of PV-Storage DC Microgrid Based on Model Prediction

Affected by the integration of distributed power sources such as photovoltaics, the low inertia characteristics of DC microgrids are gradually becoming apparent. When there are significant changes in the output and load of distributed power sources, the bus voltage is prone to significant fluctuations, even affecting system stability. A current feedforward control strategy based on Analog Virtual Synchronous Generators (AVSG) optimization is proposed for this purpose. Firstly, a small signal model is established for the control of AVSG based on energy storage inverters. The role of the virtual inertia coefficient in the voltage dynamic process has been elucidated, and the problems of current feedforward in AVSG control are analyzed. Secondly, in response to the weak improvement effect of voltage dynamic performance under AVSG control, based on the overcompensation problem of current feedforward compensation, a feedforward optimization method based on predictive models is proposed, which effectively improves the voltage fluctuations caused by distributed power generation output and load changes, and enhances the dynamic performance of DC microgrids and the inertial control effect of AVSG. Finally, the efficacy of the proposed control strategy was confirmed via MATLAB/Simulink simulation.