A hybrid control strategy for stable operation of converter-based DG resources in distribution grids with shunt active power filter capability

In this paper, a hybrid control strategy for integration of distributed generations (DGs) to distribution grids using power converters is suggested. The fuzzy tracking control based on Lyapunov function is presented for the current loop of the interfaced converter to overcome the problems of conventional control methods. The proposed control plan guarantees the system stability, appropriate tracking of the reference currents and gives a proper transient waveform. By means of the proposed control plan, the grid-interfacing converter will be utilized as: 1) power converter to inject the active power extracted from DGs to the grid, and 2) shunt active power filter (SAPF) to provide the reactive, harmonic, neutral and unbalanced currents of the grid-connected loads with a quick dynamic response. The simulation results, carried out through MATLAB/Simulink software, demonstrate the suitable operation of the suggested control plan.