Fuzzy-logic based MPPT control of grid interfaced PV generating system with improved power quality

A grid interfaced solar photovoltaic (SPV) power generating system is proposed in a three-phase four-wire (3P4W) distribution system. It consists of a SPY, a boost converter, a three-leg VSC and a transformer connected at AC mains with power quality improvement. A fuzzy logic controller (FLC) is utilized to extract the maximum power point (MPP) of a SPV system through control of an IGBT (Insulated Gate Bipolar Transistor) switch of the boost converter. This system is used for compensation of neutral current, harmonic currents, reactive power and to provide load balancing. Performance of the proposed FLC is fast in finding the MPPT than the conventional techniques used for MPPT. The dc bus voltage of the VSC is controlled to its reference value at the time of unbalanced load conditions. Performance of a 3P4W SPV generating system is tested for power factor correction, voltage regulation along with neutral current mitigation. Similar results are also verified for harmonic rejection and load balancing using MATLAB/Simulink and sim power system (SPS) block set.