Temperature Control of a Heliostat Field Solar Furnace

This article presents an approach to model and to design a temperature controller for the PROMES's 1MW solar furnace. The aim is to evaluate the operation the 1MW solar furnace in the framework of automatic temperature stress experiments, where material samples are submitted to temperature cycles. In particular, it must track the temperature profiles selected by the user and, must compensate temperature changes induced by sun power variability caused by weather conditions. A simplified model is developed to capture the main dynamics of the solar furnace. This includes the temperature dynamic model of the material sample and a model for the on-off operation of the heliostats, that have transport delays and impose quantized power levels. The controller is designed in the discrete time framework. It uses the temperature profile and the information that is provided by temperature and direct normal irradiance sensors to schedule on real-time the number of heliostats.