Study And Simulation Of Centrifugal Compressor Anti-surge Control Scheme Based On Fuzzy Controller

Centrifugal compressor, widely used in industry of petroleum, chemical andmetallurgy etc, is one of equipments of gas carrying and compression, it has a veryimportant position in the industrial production. Surge is an instability flow conditionwhen centrifugal compressor working at low flux. Once the phenomenon happened,compressor would be shut down. Further more, it could damage the wholecompressor. Therefore, the study of surge control has an important meaning for theefficiency and safety of centrifugal compressor.At present, the most frequently used anti-surge control measures is PI or PIDcontrol with the fixed limit flow method or variable limit flow method. But the fixedlimit flow method will depress efficiency and waste energy; the variable limit flowmethod is more complex and poor stability; and PID is very complex when settingits uncertain parameters. So the current surge control still exist great problems toimprove.In view of the problems of the anti-surge control of centrifugal compressor, thispaper mainly does the following job.First, through the analysis of the characteristics of surge, this paper gets thesurge line of centrifugal compressor by using the similar conversion principle, it isready for the design of anti-surge control.Secondly, this paper puts the idea of “segmentation control”, its anti-surgecontrol line is a broken line, only need to calculate same speed condition, and thealgorithm is simple, easy to be realized, and has a wide application scope. It canavoid the defects of the fixed limit flow method and variable limit flow method, andbalance the contradiction between the efficiency and stability of centrifugalcompressor.Then, this paper design the anti-surge fuzzy control system by using the fuzzycontrol algorithm, and simulate it by MATLAB. Result show that the system cancontrol the opening of valve in time according to different input flow and speed ofcentrifugal compressor, avoid the occurrence of surge phenomenon, and has relativeeffect in energy saving while achieving a good control quality.