Efficient operation of multi-zone cooling systems with storage

The aggregation/disaggregation method is shown to be an effective way of obtaining near-optimal solutions for the control of multi-zone HVAC systems with substantial energy storage, where a period of discounted energy price occurs daily. These solutions minimize energy cost by optimizing the precharging of the storage, according to the forecasted loads for the 24-hour period. Such solutions can be precomputed, off-line, and stored in a high-capacity memory, from where the most appropriate one can be retrieved for the particular forecast each day. Real-time control would be implemented by conventional PI controllers, causing actual temperatures to track the precomputed optimal profiles. The simulation results given in the paper show that substantial energy-cost savings can be achieved by such a near-optimal control scheme, and that these savings are not severely degraded when forecasts are erroneous.