Control of Harmonics and Performance Analysis of a Grid Connected Photovoltaic System

World energy consumption is increasing substantially .Growing scarcity and rising prices of fossil fuels may lead to economic instability. Continuously increasing energy consumption will overloads the distribution grids as well as the power stations, therefore having a negative impact on power availability, security and quality. One of the solutions for overcoming this is use of renewable energy resources. The energy generation from PV based DG is highly intermittent in nature and shows wide variation because of continuous fluctuations in solar radiation intensity, temperature and unpredictable weather conditions (e.g. clouds, snow, wind, etc.). This poses a major challenge for the designers of grid connected PV systems for DG applications. One of the major problems is the increase in the Total Harmonic Distortion (THD) of current injected into the grid. In this thesis basic theory of grid connected photovoltaic system and proposes a new scheme for Total Harmonic Distortion (THD) improvement in grid connected Photovoltaic (PV) systems. A fuzzy logic control can be used to improve the THD in grid connected PV systems. A comparison of PI, hysteresis control and fuzzy logic control gives the feasibility of the method. Thus the proposed scheme ensures that the THD in the injected grid current remains within the limits specified by IEEE-519, IEEE-1547. Simulation results are given to show the overall system performance. Evaluation and analysis of the 100 kW grid-connected PV system in AJCE were done depending on the change of the weather condition. The system performance was also quantified using several quantities which describe both PV array performance and the overall system performance.