SIMULATION OF MODIFIED OCC CONTROLLER FOR THREE PHASE BOOST TYPE GRID CONNECTEDINVERTER WITH PHOTOVOLATIC ARRAY

Now-a-days serious concerns have been raised over the fossil fuel electricity generation, because it pollutes our environment and depletes the energy supply. As a result alternative energy sources such as solar energy and fuel cells have gained great attention because they are friendly to the environment and flexible for installation. In this paper, the one cycle control (OCC) method and the pulse width modulation (PWM) method have been proposed for a three phase boost type grid connected inverter. A cost effective maximum power point tracking method (MPPT) integrated within the OCC. When integrated with a three phase boost type inverter, the proposed method tracks MPP with good precision and solar power is converted into three phase ac power with a single phase power stage. One stage inverters for low dc voltage to high ac voltage conversion have been reported for non-grid connected inverters based on the topology of a current source inverter. The output current of the inverter can be adjusted according to the voltage of the photovoltaic array so as to extract the maximum power from it. Compared with previously proposed approaches, this OCC method preserves the advantages of simple circuitry, good stability, fast dynamic response and maximum power point tracking (MPPT) function can be conveniently integrated into the control core.