Improvement of Frequency Characteristic of Self-Sensing Active Magnetic Bearing with Zero-Bias Current Control

2010 ◽  
Vol 130 (5) ◽  
pp. 711-712 ◽  
Author(s):  
Yohei Tamura ◽  
Toshiya Yoshida ◽  
Katsumi Ohniwa
Keyword(s):  
Frequency Characteristic ◽  
Magnetic Bearing ◽  
Bias Current ◽  
Current Control ◽  
Active Magnetic Bearing ◽  
Zero Bias

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 zero-bias current control for active magnetic bearing in power magnetically levitated spindle based on adaptive backstepping sliding mode approach

2016 ◽  
Vol 231 (20) ◽  
pp. 3753-3765 ◽  
Author(s):  
Hai Rong ◽  
Kai Zhou
Keyword(s):  
Sliding Mode Control ◽  
Sliding Mode ◽  
Magnetic Bearing ◽  
Bias Current ◽  
Active Magnetic Bearing ◽  
Adaptive Backstepping ◽  
Zero Bias ◽  
Mode Control ◽  
Backstepping Sliding Mode Control ◽  
Bearing System

The zero-bias current controlled way is proposed to cut down the power consumption of the active magnetic bearing in a power magnetically levitated spindle system. The zero-bias current controlled way is easier to realize than the zero-bias flux controlled way, since current can be detected directly, while flux is hard to be measured in practice. Besides, the active magnetic bearing suffers from lumped uncertainty including parameter uncertainty and external load, and the displacement of rotor caused by lumped uncertainty is undesirable. In practice, the upper bound of the lumped uncertainty especially the external load is hard to obtain, making it hard to choose parameters for a traditional sliding mode control. The adaptive backstepping sliding mode control method combining both the advantages of sliding mode procedure and backstepping procedure is proposed to solve this problem. Furthermore, the upper bound of lumped uncertainty is estimated in real time by an adaptive law. In this paper, first a new zero-bias current active magnetic bearing system model with lumped uncertainty is built; then two controllers based on the sliding mode control and adaptive backstepping sliding mode control methods are designed, respectively, and the stability analyses are given for the two controllers via Lyapunov function; finally, the effectiveness of the proposed adaptive backstepping sliding mode control approach for a zero-bias current active magnetic bearing system is verified by the simulation and experiment results.

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.

Lyapunov Sliding-Mode Observers With Application for Active Magnetic Bearing Operated With Zero-Bias Flux

2018 ◽  
Vol 141 (4) ◽  
Author(s):  
Arkadiusz Mystkowski
Keyword(s):  
Sliding Mode ◽  
Magnetic Bearing ◽  
Active Magnetic Bearing ◽  
Control Voltage ◽  
Zero Bias ◽  
Nonlinear Observers ◽  
Sliding Mode Observers ◽  
Voltage Saturation ◽  
Rotor Mass ◽  
Nonlinear State

This study deals with sliding-mode nonlinear observers for a flux-controlled active magnetic bearing (AMB) operated with zero-bias flux. The Lyapunov sliding-mode observer (LSMO) feedback designs are performed for the nonlinear AMB dynamics due to control voltage saturation. The nonlinear observers are designed to estimate the magnetic flux and rotor mass velocity. The observer designs are incorporated in equivalence implementation of the nonlinear state-feedback controller. The main design tools such as sliding-mode control, Lyapunov-based control are used in this framework. The proposed observers are verified by means of numerical simulations, and stability and effectiveness of the proposed observer-based feedback designs are shown.

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