Power sharing and V/F restoration of standalone AC microgrids using model predictive control

This paper presents a two-level control framework for parallel distributed generators (DGs) based ac microgrids operating in standalone mode. For primary control, droop method combined with finite control set model predictive control (FCS-MPC) is developed for proper load sharing. Using this primary control, traditional cascade linear loops have been replaced by the FCS-MPC. An improved cost function considering the voltage changing trend has been adopted in the FCS-MPC algorithm to obtain better voltage quality. After that, a secondary control is introduced to mitigate the frequency and voltage deviations caused by the primary controller when the loads are changed. The effectiveness of the proposed method is verified in simulation using Matlab/Simulink.