Event-driven optimal control of central air-conditioning systems: Event-space establishment

Real-time optimal control is widely adopted in central air-conditioning systems to improve the building energy management efficiency by adjusting system controllable variables according to system operating conditions. In time-driven optimal control, optimization actions are triggered periodically, which may not be efficient when the operating conditions of central air-conditioning systems are significantly irregular. To overcome this limitation, event-driven optimal control was proposed, in which optimization actions are triggered by "events" instead of a "clock". In event-driven optimal control, the definition of events are critical because "events" will directly affect the control efficiency and the online computational efficiency. In current literature, however, very few studies can be found on how to systematically establish a suitable event space for air-conditioning systems. This paper therefore presents a knowledge-based method for establishing event space. Case studies that were carried out in a typical commercial air-conditioning system is used to demonstrate the proposed method and its effectiveness, where real measured load and weather data were used.