A Circuit-based Photovoltaic Array Model for Power System Studies

Recent interest in distributed generation (DG) due to the opening of the electricity market and the need for alternatives to conventional fossil fuel-based electricity generation has revived interest in grid-connected photovoltaic (PV) systems. Studies need to be performed at the power system level to examine the impacts of grid-connected PV systems and several models for PV arrays have been proposed in the literature for this purpose. However, the complexities of these models and the difficulties of implementing them in software programs can be deterrents to their use. This paper proposes a simple, robust and flexible piecewise linear PV device model for dynamic and transient power system studies. The circuit-based nature of the model is beneficial because it facilitates understanding of the PV device and its behavior in the connected circuit. Software implementation is straightforward and it can even be constructed using standard software library components, as demonstrated using PSCAD/EMTDC.