Robust control of active magnetic bearing systems for helium centrifugal cold compressors

27th International Cryogenics Engineering Conference and International Cryogenic Materials Conference 2018

Zhang, S.Y.^1^2 ; Wei, C.B.^1^2 ; Yang, S.Q.^1 ; Jia, Q.M.^1^2 ; Dong, X.B.^1^2 ; Wu, J.H.^1

State Key Laboratory of Technologies in Space Cryogenic Propellants, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing

100190, China^1

University of Chinese Academy of Sciences, Beijing

100049, China^2

关键词: Active magnetic bearing systems;    Active magnetic bearings;    Chinese Academy of Sciences;    Cold compressors;    Cryogenic refrigeration systems;    Institute of Physics;    Saturated liquid;    Steady state performance;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/502/1/012055/pdf
DOI  :  10.1088/1757-899X/502/1/012055

来源: IOP

【 摘 要 】

Centrifugal cold compressors, now being developed at Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, are used to pump gaseous helium from saturated liquid helium tank to obtain super-fluid helium in cryogenic refrigeration systems. Active magnetic bearings (AMB) are replacing traditional oil-fed bearings as the optimal supporting assembly for cold compressors because of their many advantages. In this paper, five degrees of freedom AMBs are developed for the centrifugal cold compressor application. Considering the rotational speed is high, causing the nominal plant model to deviate materially from the precise mathematical model, robust H control methods are proposed to control AMB systems. Experimental results show that H controllers guarantee good dynamic and steady state performance in the closed-loop system at the rotation speed of 50 000 rpm.Published under licence by IOP Publishing Ltd.