MODELLING AND CONTROL OF GRID CONNECTED SOLAR PHOTOVOLTAIC (SPV) SYSTEM

Abstract

The demand of energy is increasing rapidly year by year worldwide & the whole world is looking for the alternative source of energy. The most populous alternative source of energy is renewable energy. Among, various available renewable energy sources, solar photovoltaic (SPV) energy is considered to be most reliable, environment friendly, pollution free and it’s unlimited amount of availability in nature. The solar energy is directly converted into electrical energy by solar cell/ module. The characteristics of PV depend upon irradiation and temperature. The temperature and the irradiation of the solar cell depend on the atmospheric conditions. Hence, it is essential to track the MPP in any conditions to assure that the maximum available power is obtained from the PV panel. In stand-alone mode PV can feed power to fixed loads & lower power rating loads only and the storage support is also required for stand-alone mode. The grid interconnected mode of PV operation offers infinite storage. When PV is interfaced to the grid power quality problems arises due to use of power electronic devices. Solar PV is modelled using single diode electrical equivalent circuit of solar cell and the characteristics of PV module are generated. The different maximum power point tracking (MPPT) algorithm is studied. Incremental conductance and perturbation and observation (P&O) is modelled and implemented. The maximum power point (MPP) is obtained using MPPT and dc-dc boost converter. The complete evacuation of generated and tracked maximum power is need of the entire system to improve the efficiency. The model of Solar PV system connected to the utility grid is modelled and simulated in MATLAB/Simulink environment. Solar PV system is controlled and synchronised to grid using synchronous reference frame theory (SRFT) algorithm and power balance theory (PBT) algorithm. To handle the power quality problems the system is run under unity power factor (UPF) and zero voltage regulation mode (ZVR). UPF is obtained on the ac mains/grid side for grid voltage and grid current and zero voltage regulation is obtained for the terminal voltage of point of common coupling (PCC) voltage.