Design and implement for control system of active magnetic bearings based on DSP

2005 ◽  
Author(s):  
Jie Cao ◽  
Lihong Cao
Keyword(s):  
Control System ◽  
Magnetic Bearings ◽  
Active Magnetic Bearings

Modeling and Vibration Control of a Flexible Rotor by Using Magnetic Bearings

2011 ◽  
Author(s):  
Takuya Nomoto ◽  
Daisuke Hunakoshi ◽  
Toru Watanabe ◽  
Kazuto Seto
Keyword(s):  
Control System ◽  
Control Method ◽  
Design Procedure ◽  
Modeling Method ◽  
Magnetic Bearings ◽  
Active Magnetic Bearings ◽  
Flexible Rotor ◽  
Modeling And Control ◽  
Elastic Modes ◽  
And Control

This paper presents a new modeling method and a control system design procedure for a flexible rotor with many elastic modes using active magnetic bearings. The purpose of our research is to let the rotor rotate passing over the 1st and the 2nd critical speeds caused by flexible modes. To achieve this, it is necessary to control motion and vibration of the flexible rotor simultaneously. The new modeling method named as Extended Reduced Order Physical Model is presented to express its motion and vibration uniformly. By using transfer function of flexible rotor-Active Magnetic Bearings system, we designed a Local Jerk Feedback Control system and conducted stability discrimination with root locus. In order to evaluate this modeling and control method, levitation experimentation is conducted.

Two-Level Control Structure of Magnetic Bearings

1993 ◽  
Vol 5 (5) ◽  
pp. 438-442 ◽  
Author(s):  
Nobuyoshi Taguchi ◽  
◽  
Takakazu Ishimatsu ◽  
Takashi Shimomachi ◽  
◽  
...  
Keyword(s):  
Control System ◽  
Vibration Control ◽  
Control Structure ◽  
Active Vibration Control ◽  
Experimental Results ◽  
Magnetic Bearings ◽  
Active Magnetic Bearings ◽  
Level Control ◽  
Whirling Motion ◽  
Active Vibration

Active magnetic bearings have several advantages over conventional mechanical and fluid bearings. However, when the magnetic bearings are used at high rotational speeds, whirling motions and vibrations synchronized with the rotation of the rotor should be considered. In order to suppress these unfavorable vibrations of rotor which is supported by magnetic bearings, we have developed an active vibration control system with a two-level control structure. Experimental results show that our active bearings system effectively suppresses the whirling motion.

Design Considerations for High Pressure Turbo Expanders Supported by Active Magnetic Bearings

2019 ◽  
Author(s):  
Alice Innocenti ◽  
Francesco Cangioli ◽  
Giuseppe Iurisci ◽  
Davide Biliotti
Keyword(s):  
High Pressure ◽  
Control System ◽  
High Density ◽  
Magnetic Bearings ◽  
Process Efficiency ◽  
Main Process ◽  
Cfd Analysis ◽  
Active Magnetic Bearings ◽  
Turbo Expander ◽  
Force Signal

Abstract Nowadays industrial processes are going toward high power density solutions. This can be read as a general increase in pressure (more than 200 barA) and fluid density indicating Turbo Expander (TEX) as a worthwhile solution to boost main process compressors and increasing process efficiency. On the other hand, inlet high pressure and high density fluids could lead to strong pressure pulsations on the impeller with consequences on the rotordynamic behavior, rotor stability and bearing integrity. For this purpose, a full annulus unsteady CFD analysis of the flow path through the inlet plenum, nozzles and impeller has been performed and analyzed in terms of resulting force FFT on the impeller. The force signal is used as an input of the rotor model supported by Active magnetic bearings (AMB), including their control system and transfer function. The aim of the study is the investigation of the influence of high density gas in TEX applications, coupling the results of unsteady CFD analysis with the dynamic response of the mechanical system. The control system parameters of magnetic bearings are included into the analysis and a sensitivity to different inlet nozzles numbers and inlet pressure levels is performed verifying the feasibility of the rotor.

Control System Design of Frequency-Feedback Magnetic Bearings

1997 ◽  
Author(s):  
Takeshi Mizuno ◽  
Kenji Araki ◽  
Hirotaka Namiki
Keyword(s):  
Control System ◽  
Digital Signal ◽  
Magnetic Bearings ◽  
Active Magnetic Bearings ◽  
Digital Control System ◽  
Load Impedance ◽  
Displacement Sensors ◽  
Digital Format ◽  
Converted Signal ◽  
Counter Circuit

Abstract The structures and features of control system are discussed for active magnetic bearings (AMBs) with frequency type of displacement sensors. The control systems are classified according to the signal conversions performed there. One of them uses a counter circuit for converting the frequency to a digital format, and the converted signal for digital signal processing. It is also pointed out that self-sensing operation can be realized by using hysteresis amplifiers because their switching rates are sensitive to load impedance. A digital self-sensing AMB, which uses a counter circuit for interface and hysteresis amplifiers for energizing the electromagnets, is manufactured for experimental study. The experimental results show that accurate suspension can be achieved with the proposed digital control system.

Effects of Impeller Tip Clearance on Centrifugal Compressor Efficiency

2007 ◽  
Author(s):  
Jari L. H. Backman ◽  
Arttu Reunanen ◽  
Juha Saari ◽  
Teemu Turunen-Saaresti ◽  
Petri Sallinen ◽  
...  
Keyword(s):  
Control System ◽  
Steady State ◽  
Mach Number ◽  
Centrifugal Compressor ◽  
Tip Clearance ◽  
Magnetic Bearings ◽  
Active Magnetic Bearings ◽  
Centrifugal Compressors ◽  
Compressor Efficiency

The paper describes the results of tip clearance variation experiments in centrifugal compressors. The compressors work at different peripheral Mach number speeds either with vaneless or vaned diffusers. In the experiments, the compressors were operated in a thermally steady state after which the axial positions of the shafts were changed. The changes in the performance of the compressors were recorded and analyzed. The clearance between the impeller and its housing affects the efficiency of the centrifugal compressor. The clearance is optimized to adapt to various phenomena: thermal expansions, impeller tip deflections, shaft bending and gyroscopic motions. The compressors of this study are equipped with active magnetic bearings. They contain a control system, which constantly measures and controls the position of the shaft. This gives useful information about impeller clearance variation, and the measured results are precise within 1/100 millimeters.

A New Modeling Technique and Control System Design of a Flexible Rotor Supported by Active Magnetic Bearings for Motion and Vibration Control

2003 ◽  
Author(s):  
Mitsuhiro Ichihara ◽  
Hideo Shida ◽  
Takahito Sagane ◽  
Hiroshi Tajima ◽  
Muneharu Saigou ◽  
...  
Keyword(s):  
Control System ◽  
Vibration Control ◽  
System Design ◽  
Physical Model ◽  
Magnetic Bearings ◽  
Control System Design ◽  
Active Magnetic Bearings ◽  
Flexible Rotor ◽  
Reduced Order ◽  
And Control

This paper proposed a new modeling technique and control system design of a flexible rotor using active magnetic bearings (AMB) for motion and vibration control. The purpose of the research was to pass through a critical speed and achieve high-speed rotation. To achieve this, it is necessary to control both vibration and motion. Even though reduced order physical model [1] that we used before is available technique in expressing vibration, this technique cannot express motion. Thus we propose an extended reduced order physical model [2] that can simultaneously express motion and vibration. Further, by using the model we apply the design of a new controller that combined proportional integral derivative (PID) with linear quadratic (LQ) control to a flexible rotor. The procedure we propose is verified by simulations as being effective for a flexible rotor.

scholarly journals INDUCTIVE LINEAR DISPLACEMENT SENSOR IN ACTIVE MAGNETIC BEARING

2019 ◽  
Vol 3 ◽  
pp. 151
Author(s):  
Sergei Loginov ◽  
Dmitriy Fedorov ◽  
Igor Savrayev ◽  
Igor Plokhov ◽  
Andrey Hitrov ◽  
...  
Keyword(s):  
Control System ◽  
High Speed ◽  
High Reliability ◽  
Magnetic Bearing ◽  
Linear Displacement ◽  
Magnetic Bearings ◽  
Active Magnetic Bearing ◽  
Displacement Sensor ◽  
Main Trend ◽  
Active Magnetic Bearings

Active magnetic bearings are increasingly used in various fields of industry. The absence of mechanical contact makes it possible to use them in ultra-high-speed electric drives. The main trend of active magnetic bearings development is the improvement of the control system. The main problem of the control system is the displacement sensor (most of them has low accuracy and large interference). The sensor must have the following properties: simple in realization, high linearity of the characteristic, high sensitivity and noise immunity, high reliability. At the present time there is no sensor that satisfies all these conditions. Most manufacturers use various kinds of filters to get an accurate position signal. This increases the response time of the control system. Thus, problem of designing and modeling the position sensor, considered in the article is topical.

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