SINGLE PHASE GRID CONNECTED INVERTER SERVING TWO PV PANELS UNDER DIFFERENT ATMOSPHERIC CONDITIONS

Abstract

Innovation in photovoltaic systems has been constantly increasing since its invention and integration to the power grid. The cost of generating power has been decreasing with the invention of new technologies. The control of energy has also become more dynamic. With these increasing innovations the efficiency to extract maximum solar power from a system is increasing. In this work a single stage one phase grid tied inverter which has two serially connected PV panels as its input is designed. A transformerless single stage topology has been used which has the advantage of less weight, low volume, low complexity and less cost. The PV panels has been exposed to varied conditions of irradiance and temperature. Since the serially connected modules are only two it is easier to extract maximum power from each one and control system is also less complex. The control strategies for the synchronization of the proposed inverter topology with the power grid has been carried out using a conventional PI controller and a Fuzzy Logic controller. A 1.5 KW model of the scheme has been simulated in MATLAB-Simulink where the PV modules are exposed to different conditions of temperature and irradiance. Bothe the PV panels are controlled separately making the control scheme as decoupled. The operation of the inverter is discussed with an in depth analysis of the control scheme with the two controllers. A comparative analysis has also been carried out using the results obtained for the Proportional Integral Controller and Fuzzy Logic Controller.