Predictive control system for modulated supply of PV Energy
The use of renewable energy sources to supply electricity in customer grids is a current practise in developed countries and, particularly, in the case of distributed solar energy generation grids. However, because of the unsteady behavior of the renewable electric energy sources, as solar photovoltaic production, it produces fluctuations in the electric grids; then, an accurate renewable energy production forecast is usually required. In addition, errors in the production forecast can be solved by using a production-storage controlled system.
In this work, a predictive control system was designed in order to reduce the fluctuations of electric supply from the photovoltaic installation, taking into account a solar radiation forecast provided by WRF numerical weather forecast model. Numerical simulations of this PV controlled system were performed at three different sites (rural, suburban and urban) using hourly and 10-minutes average solar radiation data, in order to estimate the reduction in energy supply fluctuations obtained with this control system.
The results show that the energy supplied is increased by 12% using this control system. In addition, an optimum storage size for every site can be estimated from the simulations results, taking into account both the energy production and the storage cost.