Parameters sensitivity analysis of the controller based on unified control strategy in a photovoltaic microgrid

The controller based on unified control strategy for the DC/AC converters in a photovoltaic microgrid (PV-MG) is proposed for both grid-connected and islanding mode operation and seamless switching. The unified controller is designed by combining the power PI regulator with droop control to realize the current control and voltage control at the grid-connected and islanding modes respectively, and the automatic and seamless switching between the two modes of PV-MG can be realized. According to the step response dynamic index and stability constraints, the parameters of the controller are optimized with root locus methods. The Matlab/Simulink simulation reslults show the feasibility and effectiveness of the proposed control algorithm.