1 Department of Electronic Systems, The Technical Faculty of IT and Design, Aalborg University, VBN2 Automation & Control, The Technical Faculty of IT and Design, Aalborg University, VBN3 The Faculty of Engineering and Science (TECH), Aalborg University, VBN4 Aalborg University Space Center, The Technical Faculty of IT and Design, Aalborg University, VBN5 Strategic Research Centre on Zero Energy Buildings, The Faculty of Engineering and Science, Aalborg University, VBN6 Aalborg U Robotics, The Faculty of Humanities, Aalborg University, VBN
In this paper, a fault tolerant control (FTC) strategy is proposed for evaporator superheat control in supermarket refrigeration systems. Conventional control uses a pressure and temperature sensor for this purpose, however, the pressure sensor can fail to function. A contingency control strategy, based on a maximum slope-seeking control method and only a single temperature sensor, is developed to drive the evaporator outlet temperature to a level that gives a suitable superheat of the refrigerant. The FTC strategy requires no a priori system knowledge or additional hardware and functions in a plug & play fashion. The strategy is outlined by means of procedural steps as well as a flow chart that also illustrates the process of automatic tuning of the maximum slope-seeking controller. Test results are furthermore presented for a display case in a full scale CO2 supermarket refrigeration system.
Proceedings of the 2nd International Conference on Control and Fault Tolerant Systems, 2013
Main Research Area:
2nd International Conference on Control and Fault Tolerant Systems, 2013