Reducing energy costs by optimizing controller tuning

The proportional integral derivative (PID) controller is the most dominant form of automatic controller in industrial use today. With this technique, it is necessary to adjust the controller parameters according to the nature of the process. This tailoring of controller to process is known as controller tuning. Controller tuning is easily and effectively performed using tuning rules (i.e. formulae for controller tuning, based on process information). Such tuning rules allow the easy set up of controllers to achieve optimum performance at commissioning. Importantly, they allow ease of re-commissioning if the characteristics of the process change. The paper outlines the results of recent work in the collation of industry-relevant PI and PID controller tuning rules, which may be applied to a variety of applications with the aim of reducing energy costs. The control of a pilot scale heating, ventilation and air-conditioning (HVAC) plant is detailed as a case study.