Comparative Power Quality Performance Evaluation of Grid-Connected Solar PV System

Transformerless grid-tied PV structure comprising two-stage power conversion has been proposed in this work. In the first stage, DC–DC conversion take place by implementing MPPT algorithm, and in the second stage, DC–AC conversion take place using two-level voltage source converter (VSC). The proposed system is regulated in a manner such that the grid operates in unity power factor mode irrespective of the type of loads. For DC–DC conversion, perturb and observe (P&O) and fuzzy logic controller (FLC) method have been employed to track maximum power point of PV array. For Inverting conversion, control algorithm based on instantaneous reactive power theory has been employed for two-level VSC. Performance of the two systems with different MPPT algorithms, i.e. system with P&O algorithm and system with FLC algorithm, is compared in terms of THD, reactive power compensation, and operating power factor for power quality analysis. The systems have been designed, modelled, and their performances have been verified using MATLAB/Simulink.