Comparative evaluation of Fuzzy-PI and PI control methods for a three phase grid connected inverter

This research addresses the issue of power electronics control scheme for grid integration of a distribution generation unit. For the improvement of the current control and DC bus voltage control, the application of the PI and Fuzzy-PI controller is investigated. Theoretical and mathematical analysis of the internal structure of the PI and Fuzzy-PI controller is carried out. Using the software Matlab/Simulink, the behavior of the controllers for DC bus voltage and current control is investigated. A comparative evaluation of the controllers both in steady state and transient response is presented. Furthermore the PI and Fuzzy-PI controller are compared based on THD
_i
index of the inverter's current. The ability of the inverter to provide ancillary services to the electric power system though the uninterrupted compensation of the reactive power of the load is studied, as well.