Adaptive Bias Current Control in Active Magnetic Bearings for Energy Optimization

2011 ◽  
Author(s):  
Satoshi Ueno ◽  
M. Necip Sahinkaya
Keyword(s):  
Power Consumption ◽  
Control Method ◽  
Optimization Method ◽  
Magnetic Bearing ◽  
Descent Method ◽  
Bias Current ◽  
Current Control ◽  
Experimental Results ◽  
Active Magnetic Bearing ◽  
Steepest Descent Method

This paper introduces an adaptive bias current control method for an active magnetic bearing (AMB). The bearing force is analyzed theoretically, and the dynamic performance of the magnetic bearing for various bias currents is discussed. Then power consumption is analyzed and the optimum bias current that minimizes power consumption is derived. A novel optimization method using a steepest descent method is proposed. This requires less computing power than the former optimization method using a recursive Fourier transform algorithm. Experimental results show that the optimized bias current can be achieved by the proposed method. However, the dynamics of the rotor is affected by the bias current variation. In order to overcome this problem, the effects of parameter errors are investigated and correction methods are introduced. Experimental results show that the rotor dynamics are not affected by the variable bias current if the parameters are corrected. Results are also presented for machine run-up and run-down.

Nonlinear Low Bias Current Control for Magnetic Bearing System Using Active Disturbance Rejection Technology

2021 ◽  
Author(s):  
Yichen Yao ◽  
Yixin Su ◽  
Suyuan Yu
Keyword(s):  
Control Strategy ◽  
Disturbance Rejection ◽  
Control Method ◽  
System Modeling ◽  
Magnetic Bearing ◽  
Bias Current ◽  
Current Control ◽  
Zero Bias ◽  
Active Disturbance Rejection ◽  
Bearing System

Abstract Magnetic bearing is widely used in helium-turbine circle of the high temperature gas-cooled reactor and many other highspeed rotating machinery because of its unique advantages in vibration and noise reduction. However, the power consumption of magnetic bearing increases its cost of use. Moreover, the design of magnetic bearing controller relies on accurate system modeling. All these restrict the industrial application of magnetic bearings. Based on the structure of the eight-pole magnetic bearing and its corresponding traditional decentralized differential PID control strategy, this paper proposes a magnetic bearing control framework including expected bearing force realization control strategy and centralized control strategy. Under this framework, a nonlinear low bias current control method for magnetic bearing system is given. Afterwards, an active disturbance rejection controller based on low(zero) bias current is proposed to compensate the gyroscopic disturbance and modeling uncertainty of the system. The controller can keep small loss of magnetic bearing and have good stability. It has a frame of active disturbance rejection control (ADRC) and its compensation performance is analyzed. In order to verify the effectiveness of the controller, a corresponding experimental verification is carried out on the test rig. The results show that the control strategy is effective.

The Research and Design of the Adaptive Pulse Demagnetizer

2012 ◽  
Vol 182-183 ◽  
pp. 427-430
Author(s):  
Li Feng Wei ◽  
Liang Cheng ◽  
Xing Man Yang
Keyword(s):  
Adaptive Control ◽  
Power Consumption ◽  
Low Power ◽  
Control Method ◽  
Experimental Results ◽  
Low Power Consumption ◽  
Reliable Operation ◽  
Charge Current ◽  
Long Life ◽  
Research And Design

A adaptive control method of the pulse demagnetizer was presented, Can adjust the strength of the charge current automatically according to the changes of the magnetic content to ensure the constant of the magnetic field.The experimental results have shown that it has the advantages of low power consumption, strong anti-interference capability, stable and reliable operation, long life and good demagnetizing effect, when compared to the conventional demagnetizers.

scholarly journals Active Control for Multinode Unbalanced Vibration of Flexible Spindle Rotor System with Active Magnetic Bearing

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Xiaoli Qiao ◽  
Guojun Hu
Keyword(s):  
High Speed ◽  
Control Method ◽  
Magnetic Bearing ◽  
Rotor System ◽  
Active Magnetic Bearing ◽  
Influence Coefficient ◽  
Control Effect ◽  
High Speed Cutting ◽  
Influence Coefficient Method ◽  
Cutting Processes

The unbalanced vibration of the spindle rotor system in high-speed cutting processes not only seriously affects the surface quality of the machined products, but also greatly reduces the service life of the electric spindle. However, since the unbalanced vibration is often distributed on different node positions, the multinode unbalanced vibration greatly exacerbates the difficulty of vibration control. Based on the traditional influence coefficient method for controlling the vibration of a flexible rotor, the optimal influence coefficient control method with weights for multinode unbalanced vibration of flexible electric spindle rotors is proposed. The unbalanced vibration of all nodes on the whole spindle rotor is used as the control objective function to achieve optimal control. The simulation results show that the method has an obvious control effect on multinode unbalanced vibration.

Isotropic Optimal Control of Active Magnetic Bearing System

1996 ◽  
Vol 118 (4) ◽  
pp. 721-726 ◽  
Author(s):  
Cheol-Soon Kim ◽  
Chong-Won Lee
Keyword(s):  
Optimal Control ◽  
System Analysis ◽  
Control Method ◽  
Magnetic Bearing ◽  
Active Magnetic Bearing ◽  
Control Effort ◽  
Response Component ◽  
Unbalance Response ◽  
Control Scheme ◽  
Bearing System

As a new rotor control scheme, isotropic control of weakly anisotropic rotor bearing system in complex state space is proposed, which utilizes the concepts on the eigenstructure of the isotropic rotor system. Advantages of the scheme are that the controlled system always retains isotropic eigenstructure, leading to circular whirling due to unbalance and that it is efficient for control of unbalance response. And the system analysis and controller design becomes simple and yet comprehensive since the order of the matrices treated in the complex domain approach is half of that in the real approach. The control scheme is applied to a rigid rotor-active magnetic bearing system which is digitally controlled and the control performance is investigated experimentally in relation to unbalance response and control energy. It is found that the isotropic optimal control method, which essentially eliminates the backward unbalance response component, is more efficient than the conventional optimal control in that it gives smaller major whirl radius and yet it often requires less control effort.

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