PSCAD/EMTDC model of a 3-phase grid connected photovoltaic solar system

Photovoltaic (PV) solar farms are being increasingly utilized for producing energy, worldwide. To integrate such solar farms with the grid, a thorough technical study is required in terms of their impact on system voltage, power quality, response to faults and short circuit contributions, etc. These studies require a complete modeling of the PV solar system in an electromagnetic transient software environment like PSCAD/EMTDC. This paper presents a PSCAD/EMTDC model of PV solar panels, the grid connected three phase voltage sourced inverter (VSI) and its controller system. The VSI control is implemented with current control loops. A maximum power point tracking (MPPT) algorithm is implemented to get the maximum output power for any given solar irradiation and temperature. This is integrated with the inverter control in such a way that the requirement of DC-DC converter is eliminated to harvest the maximum power. The inverter model also maintains near unity power factor regardless of the level of power output and maintains an acceptable level of current harmonics. Finally, the developed model is validated with the output of a commercially used PV module.