This work addresses a special requirement of the control strategy for grid interfacing inverter in three-phase four wire distribution systems to deal with power quality problems. A controller based on instantaneous real and reactive power (p-q) theory is proposed for improving harmonic patterns of all the
three phases. Total harmonic distortion (THD) of voltage and current for all the three phases is found remarkably low when system is observed with the proposed controller. The harmonic patterns are studied while system is having major varieties of non- linear loads. Effectiveness of control scheme is verified throughresponses obtained at source side and load side. MATLAB / SIMULINK implementation of a three-phase four wire inverter is presented.
Power quality, p-q theory, Grind, Shunt active filter, Inverter, Non-linear load