An adaptive PR controller for inverter-based distribution generation with active damped LCL filter

The fact distribution generation (DG) importance is growing rapidly in the recent years where the coupling between DG sources and the grid is done through inverters where exporting low distorted currents and high quality output power that copes with IEEE standards are main concerns. This paper demonstrates the regulation of the inverter current using proportional resonant (PR) controller that adapts to the grid voltage frequency to ensure reliable operation. Also to improve the quality of the output, an LCL passive filter is used as well as a demonstration of an alternative easier approach to achieve virtual damping of the resonance effect of the filter and construct an inner control loop improving robustness and stability simultaneously. The proposed concept has been simulated using Matlab Simulink for a 4KW IBDG.