ENHANCEMENT OF GRID INTERACTIVE PV SYSTEM USING A NOVEL FUZZY LOGIC BASED MPPT

In this project, an MPPT based on simple fuzzy logic control strategy is proposed for two-stage grid interactive PV system. DC-DC boost converter as first stage and three-phase voltage source inverter as second stage. The boost converter stage provides not only the boosting of PV output voltage for grid connectivity but also used as MPP tracker. The second inverter stage is used for multiple functions: (i) active power injection, (ii) harmonic compensation of non linear load connected with the grid, and (iii) reactive power compensation of the load. The additional functionality of the PV inverter as a shunt active power filter increases the overall efficiency of the system. The proposed fuzzy logic MPPT controller accepts single input that is slope of P-V curve (dp/dv) and generates the duty cycle for the boost converter as an output to operate the PV array at MPP and gives the maximum PV power to be injected in the grid. The proposed technique gives faster convergence with less complexity. The PV system is extracting maximum power that varies with the change in solar insolation and temperature. To increase the efficiency of the PV system, it is required to operate at the Maximum Power Point (MPP). The simulation results validate the performance and stability of the grid interactive PV system using the proposed algorithm for active current injection as well as harmonics and reactive power compensation