Steady state error elimination and harmonic compensation using proportional resonant current controller in grid-tied DC microgrids

Optimized operation of grid-tied DC microgrids requires the application of an efficient current control strategy. Proportional resonant (PR) control is found to be one of the suitable control schemes to regulate grid currents in grid connected Voltage Source Converters. The paper focuses on achieving minimal steady state error between the desired and actual values of the series injected grid currents in the system. An additional advantage of selective harmonic compensation enhances the employability of this new breed of controllers. Tracking converter reference currents in the stationary reference frame is investigated to cancel out the shortcomings encountered while using conventional method comprising proportional integral controllers. Simulation research is carried out on the specified control area and a detailed discussion of both analytical and simulation results are presented. Simulation results furnished validate the test system connected to a linear inductive load when synchronized with the AC main power grid.