CH-09-062 -- Stability of Temperature Control in VAV Systems PDF

Indoor air temperature control of a single zone space is studied. In air-conditioning systems, a step or an impulse in setpoint or a slight disturbance, can lead to hunting. Variable air volume (VAV) control is very common in air-conditioning systems. The supply airflow rates to the space can be controlled by motorized dampers or by fan speed control. VAV systems are assumed to be an essential source of hunting. To explore the possible connection between VAV systems and hunting, a dynamic system model is formulated as a bilinear model with time-delayed feedback (by P or PI control actions), and a parametric analysis of the stability region is presented. Results are given that show the stability region affected by the selection of setpoint values and control parameters. This analysis is conducted to help us tune proportionalintegral- derivative (PID) controllers to achieve good control performance.

Units: SI