Design and Analysis of Fuzzy Control in a Variable Speed Refrigeration System

  • Hua, Li (Department of Refrigeration and Air-conditioning Engineering, Graduate School, Pukyong National University) ;
  • Jeong, Seok-Kwon (School of Mechanical Engineering, Pukyong National University)
  • 발행 : 2007.06.30


This paper deals with fuzzy control with a feedforward compensator to progress both energy saving and coefficient of performance (COP) in a variable speed refrigeration system. Both the capacity and superheat are controlled simultaneously and independently in the system. By adopting the fuzzy theory, the controller design for the capacity and superheat is possible without depending on a dynamic model of the system. Moreover, the feedforward compensator of the superheat can reduce influence of the interfering loop between the capacity and superheat. Some experiments are conducted to design appropriate fuzzy controller by an iteration manner. The results show that the proposed fuzzy controller with the compensator can establish good control performances for the complicated refrigeration system in spite of its inherent strong non-linearity. Also, the fuzzy control performances were investigated by comparing to the model based PI control experimental results to evaluate transient behavior under the control.



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