Reactive Power Control in Grid Connected Photovoltaic System

Abstract

An ever increasing population, modernization and industrialization has led to the increase of energy requirement in all sectors of economy. Fossil fuels have been the most important source of energy from many years but they are finite and will deplete in coming years. They are nonrenewable and cause global carbon emissions which is an important environmental concern in the present scenario. Among all the available renewable sources, solar energy is used widely because it is clean, noise free and the photovoltaic (PV) system can be installed easily to convert the solar energy into electricity. PV system can work in standalone mode as well in grid connected mode. During the dissertation work, a PV system connected to grid has been modeled with the help of MATLAB/Simulink in which Perturb and Observe (P&O) Maximum Power Point Tracking (MPPT) technique is used to make the system operate at maximum power point and hence constant output voltage of DC-DC boost converter is observed. Power generated by PV array has to be fed to the grid but the output voltage of PV array is DC which is converted to AC with the help of voltage source inverter (VSI) and is then fed to the grid. In order to manage the flow of reactive power in the system and switching pattern of voltage source inverter, synchronous reference frame (SRF) theory is implemented which is a d-q control based on conversion of abc currents involving algebraic equations. The complete grid connected PV system is analyzed for different values of load and reactive power compensation is investigated in this work.