Early measure of synchronization operations in supermarket refrigeration systems

The objective of a supermarket refrigeration system is mainly to preserve the foodstuffs at a proper temperature. Practice shows that the temperature in one display case influences the temperature in the neighboring ones. These interactions from time to time lead to a synchronization operation in the display cases, which causes a high wear on the compressor, inferior control performance and increased energy consumption. In the paper, we analyze the synchronization dynamics using chaos theory and show that the system has the complex chaotic behavior, which is far away from the synchronization. Therefore, we propose a concept that the system may be de-synchronized by making it chaotic. The maximum Lyapunov exponent (MLE) is usually used to estimate the level of chaos. We use it as a measure of performance for the tendency of the system to synchronize. Thus, early warnings about the undesired synchronous behavior can be given to the control system for continuous optimization of the performance.