IMPLEMENTATION OF PV GRID CONNECTED INVERTER

Abstract

This thesis presents a performance analysis of single-phase five-level inverter for grid connected photovoltaic (PV) system. Proposed PV system is a two stage multi-string inverter configuration with a novel PWM control scheme, in which six PV modules are cascaded together in parallel configuration and connected to a live-level inverter to produce output voltage in five levels. The first stage ensures maximum point tracking of a PV module through a dc-dc converters and second stage is for inversion purpose. Maximum power point tracker (Ml'Pl') is a simple dc-dc converter whose control is achieved through the tracking algorithms. So analysis of MPPI' under two distinct point of views: dc-dc converter and tracking algorithm is presented. 'l'he main function of a PV array is to suppiy active power to the grid and local loads connected to it. If the loads with reactive power requirement are connected to the grid, then how the inverter will fulfill this requirement without disturbing the grid is going to be studied in this thesis by adding reactive power control function. To emphasize the capability of an inverter, the test system is subjected to different loads: linear loads with only active power requirement and linear loads with both active and reactive power requirements and their simulation results in MATLAB/Simulink are presented. Same technique has been extended to the three phase grid connected PV system and their results are presented.