Modelling and simulation of a lighting control system

The objective of this paper was to regulate the amount of illumination in a room at a constant level, irrespective of the disturbances from outside such as weather conditions or the use of blinds to avoid the glare risk. In order to produce a model of the lighting system in our project, the supply voltage to the lamp dimmer circuits was varied stepwise and the resulting response – measured by the light sensors – was captured with a data-acquisition board. A nonlinear static characteristic in series with a linear 3rd order dynamic system was obtained from this experiment. The model was then used to implement and to validate a lighting system simulator, which was then further used to design, tune, test and evaluate efficient lighting controllers. The control design was rather challenging because the system is highly nonlinear and because undesired interaction occurs between multiple illumination zones in a big office room. The main benefits are a higher level of comfort and a continuous saving of energy.