Surge Control of Active Magnetic Bearing Suspended Centrifugal Compressors

2011 ◽  
Author(s):  
Se Young Yoon
Keyword(s):  
Magnetic Bearing ◽  
Active Magnetic Bearing ◽  
Centrifugal Compressors ◽  
Surge Control

Investigation on the Seal Structure Design and Rotor Vibration Controller for Back-to-Back Centrifugal Compressor

2016 ◽  
Author(s):  
Qihang Li ◽  
Weimin Wang ◽  
Binbin Liu ◽  
Xing Shao ◽  
Shuai Gao
Keyword(s):  
Centrifugal Compressor ◽  
Control Strategy ◽  
High Efficiency ◽  
Volume Flow Rate ◽  
Magnetic Bearing ◽  
Structure Design ◽  
Active Magnetic Bearing ◽  
Rotor Vibration ◽  
Centrifugal Compressors ◽  
Velocity Feedback

Centrifugal compressors, as the key equipment in process industries such as petroleum refinery and chemical, are faced with the challenges of rotordynamic stability and high efficiency on condition of high pressure ratio and volume flow rate. The back-to-back centrifugal compressor has a reputation of higher efficiency for its smaller balance piston drum and axial thrust bearing than those of through-in-line compressor. However, fluid non-conservation excitation forces at the balance drum seal will prominently affect the stability of rotor; there are risks of rotor-stator rubbing caused by large vibration amplitude at balance drum seal when the rotor loses stability. Aiming at this case, the patented integrated structure of balance drum seal and vibration controller was presented which combines the function of active-magnetic-bearing (AMB) and hole-pattern-seal (HPS). The feasibility of the integrated AMB-HPS was verified by ANSYS, and the effect of the diameter and depth of the hole on the performance of AMB was studied as well. A test rig was built to test the stiffness-parameters of the integrated AMB-HPS. Finally, the rotor vibration controller was investigated focusing on (1) balancing the cross couple force exerted by the seal on the rotor by the control strategy of displacement feedback, and (2) adding additional damping by the control strategy of velocity feedback. Simulation work of an industrial rotor was carried out. The results indicate that: (1) the presented seal structure can provide enough force for controlling the vibration of the rotor; (2) displacement feedback strategy has less energy consumption than the velocity feedback at the same control effect. The work of this paper can provide the foundation for the designing of new centrifugal compressors.

scholarly journals Design and Characterization of a Centrifugal Compressor Surge Test Rig

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Kin Tien Lim ◽  
Se Young Yoon ◽  
Christopher P. Goyne ◽  
Zongli Lin ◽  
Paul E. Allaire
Keyword(s):  
Centrifugal Compressor ◽  
Pressure Fluctuations ◽  
Magnetic Bearing ◽  
Tip Clearance ◽  
Active Magnetic Bearing ◽  
Test Rig ◽  
Compressor Surge ◽  
Surge Control ◽  
Compressor Performance

A detailed description of a new centrifugal compressor surge test rig is presented. The objective of the design and development of the rig is to study the surge phenomenon in centrifugal compression systems and to investigate a novel method of surge control by active magnetic bearing servo actuation of the impeller axial tip clearance. In this paper, we focus on the design, initial setup, and testing of the rig. The latter two include the commissioning of the rig and the experimental characterization of the compressor performance. The behavior of the compressor during surge is analyzed by driving the experimental setup into surge. Two fundamental frequencies, 21 Hz and 7 Hz, connected to the surge oscillation in the test rig are identified, and the observed instability is categorized according to the intensity of pressure fluctuations. Based on the test results, the excited pressure waves are clearly the result of surge and not stall. Also, they exhibit the characteristics of mild and classic surge instead of deep surge. Finally, the change in the compressor performance due to variation in the impeller tip clearance is experimentally examined, and the results support the potential of the tip clearance modulation for the control of compressor surge. This is the first such demonstration of the feasibility of surge control of a compressor using active magnetic bearings.

Model Validation for an Active Magnetic Bearing Based Compressor Surge Control Test Rig

2010 ◽  
Vol 132 (6) ◽  
Author(s):  
Se Young Yoon ◽  
Zongli Lin ◽  
Kin Tien Lim ◽  
Christopher Goyne ◽  
Paul E. Allaire
Keyword(s):  
Mathematical Model ◽  
Magnetic Bearing ◽  
Tip Clearance ◽  
Active Magnetic Bearing ◽  
Dynamic Responses ◽  
Compression System ◽  
Compressor Surge ◽  
Theoretical Predictions ◽  
Surge Control ◽  
The Mathematical Model

In this paper, we present experimental test data for the validation of a recently introduced mathematical model for centrifugal compression systems with variable impeller axial clearances. Employing the active magnetic bearings (AMBs) of a compressor built for the experimental study of surge, the axial clearance between the impeller and the static shroud is servo controlled, and the measured variations in the compressor output flow are compared with the mathematical model. The steady state and the dynamic responses of the compression system induced by varying the impeller tip clearance are measured and compared with the theoretical predictions, and the states of the compression system in surge condition are collected and analyzed. Parameters in the compression system model, such as the Greitzer parameter B and Helmholtz frequency ωH are experimentally identified. Also, the servo dynamics of the magnetic bearing that controls the axial impeller position is determined experimentally. To further validate the mathematical model and the feasibility of using the impeller tip clearance for controlling surge, we present a design example for an active surge controller based on the derived model, and simulate the response of the compression system. This design exercise also helps us understand the possible challenges that one could face in the design and implementation of a successful surge controller.

scholarly journals Application of the Dynamic Iterative Learning Control to the Heteroplanar Active Magnetic Bearing

2020 ◽  
Vol 53 (2) ◽  
pp. 1511-1516
Author(s):  
Lukasz Hladowski ◽  
Arkadiusz Mystkowski ◽  
Krzysztof Galkowski ◽  
Eric Rogers ◽  
Bing Chu
Keyword(s):  
Iterative Learning Control ◽  
Learning Control ◽  
Magnetic Bearing ◽  
Iterative Learning ◽  
Active Magnetic Bearing

Analysis of supercritical pitchfork bifurcation in active magnetic bearing-rotor system with current saturation

2021 ◽  
Vol 104 (1) ◽  
pp. 103-123
Author(s):  
Xiaoshen Zhang ◽  
Zhe Sun ◽  
Lei Zhao ◽  
Xunshi Yan ◽  
Jingjing Zhao ◽  
...  
Keyword(s):  
Pitchfork Bifurcation ◽  
Magnetic Bearing ◽  
Rotor System ◽  
Active Magnetic Bearing ◽  
Current Saturation
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