Simulation Model of a Grid-Connected Single-Phase Photovoltaic System in PSCAD/EMTDC

In this paper, a complete simulation model of a grid-connected single-phase two-stage photovoltaic (PV) system with associated controllers is presented. The simulation model is developed in PSCADIEMTDC simulation program. The component models of the grid-connected PV system include a PV array, a dc-dc boost converter, a voltage source converter (VSC) and an LCL filter. Components of the LCL filter, the dc-link capacitor of the VSC and the inductor of the dc-dc boost converter are established theoretically and that are used in modelling the grid-connected PV system. The control architecture of the presented system incorporates a synchronous reference frame phase-locked-loop (s-PLL), a stationary frame current controller, a dc-link voltage controller, a dc-dc boost converter controller and a maximum power point tracking (MPPT) algorithm. Control design methodologies are described in detail. Simulation studies confirm that the modelling and control design approaches taken are robust and lead to a system with acceptable performance.