Title :
On-line auto-tuning of PI control of the superheat for a supermarket refrigeration system
Author :
Yang, Zhenyu ; Andersen, Casper ; Izadi-Zamanabadi, Roozbeh
Author_Institution :
Dept. of Energy Technol., Aalborg Univ., Esbjerg, Denmark
Abstract :
An online PI auto-tuning method is proposed for superheat control for a type of supermarket refrigeration systems. the proposed procedure consists of three serial steps: Step-One uses one of the two proposed empirical methods, namely multi-step method and relay method, for modeling initialization. The objective is to guide the initial (superheat) operation into a neighborhood of the predefined set-point and keep the operation inside afterwards. Step-Two identifies a FOPDT model for the concerned local dynamic either through a Modified Area Method (MAM) or a Least-Square Prediction (LSP) method. A PI controller is auto-tuned based on the obtained FOPDT model and the SIMC method in Step-Three. The proposed method is implemented on a real-sized physical system and the experimental results showed a promising potential to apply the proposed method into commercial development.
Keywords :
PI control; control system synthesis; heat transfer; least squares approximations; prediction theory; refrigeration; FOPDT model; PI controller; SIMC method; least-square prediction method; modified area method; multistep method; online auto-tuning; relay method; superheat control; supermarket refrigeration systems; Heating; Refrigerants; Relays; Robustness; Tuning; Valves;
Conference_Titel :
Control Applications (CCA), 2011 IEEE International Conference on
Conference_Location :
Denver, CO
Print_ISBN :
978-1-4577-1062-9
Electronic_ISBN :
978-1-4577-1061-2
DOI :
10.1109/CCA.2011.6044368
