Low cost microprocessor based optimal controller for solar cooling systems

A low cost microprocessor based optimal controller for a typical solar cooling system was implemented. Controller simulation results indicate that a net reduction of more than 30% in auxiliary energy is possible due to overall performance improvement. A dynamic mathematical model for a lithium bromide-water (LiBr-Water) chiller was developed to be used for deriving an optimal control algorithm. A control law based on the minimization of a quadratic performance index that incorporates enclosure temperature deviations and auxiliary energy was derived. The resulting controller, targeted for end-users, is versatile and inexpensive.