An augmented circuit model for magnetic bearings including eddy currents, fringing, and leakage

Meeker, David C.; Maslen, Eric H.; Noh, Myounggyu

doi:10.1109/20.508385

Cited by 54 publications

(30 citation statements)

References 9 publications

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“…This paper extends the work presented in [1,4] and addresses the aforementioned problems via integrated models based on Fig. 1(b) to describe the high frequency behaviour of a complex radial 8-pole heteropolar AMB.…”

Section: Introductionmentioning

confidence: 94%

“…The magnetic circuit of the bearing is modelled using a reluctance network which includes effects such as leakage, fringing, and eddy-currents [1]. Fringing effects are compensated for by employing accurate air gap reluctance values.…”

Section: Reluctance Network Modelmentioning

confidence: 99%

“…Fig. 1(a) displays a frequency dependent lumped parameter model proposed by [1] to describe the frequency response of a laminated heteropolar AMB. The equivalent series resistance and inductance are firstly obtained from a reluctance network model that uses a complex material permeability term.…”

Section: Introductionmentioning

confidence: 99%

“…Two methods of determining the main inductance and the series core resistance are examined. First, the reluctance network model proposed by [1] is utilised, and secondly, a modelling technique proposed by [4] is adopted. The latter technique models the complex magnetic structure as a single magnetic core with no air gap and a new equivalent material permeability.…”

Section: Introductionmentioning

confidence: 99%

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Frequency dependent impedance model for heteropolar magnetic bearings

Ranft

Schoor

Rand

2015

Applied Mathematical Modelling

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a b s t r a c tAccurate analytical models are fundamental to design and optimise high performance magnetic bearings. Understanding the bearing's dynamic behaviour over its operational envelope is essential to this task and is performed through frequency response analyses. This work formulates an integrated frequency dependent model of a radial heteropolar active magnetic bearing (AMB) in which terms for the stray capacitance, winding resistance, and winding leakage inductance are included. The model is based on a lumped parameter model frequently used for high frequency laminated inductor applications. Two magnetic core models are evaluated. The first comprises a reluctance network approach and incorporates eddy-current, fringing, and leakage correction terms, while the second constitutes a single gapless magnetic core of equivalent length and effective permeability. The accuracy of the latter is improved by intuitively adjusting two parameters in the analytical model. The magnetic bearing parameters calculated as functions of frequency are compared with practical measurements. The integrated single core model demonstrates superior correlation with experimental results for frequencies up to 1 MHz.

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Section: Introductionmentioning

confidence: 94%

Section: Reluctance Network Modelmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Frequency dependent impedance model for heteropolar magnetic bearings

Ranft

Schoor

Rand

2015

Applied Mathematical Modelling

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“…On the other hand, a closed-loop controller is definitely required because the open-loop of the magnetically levitated proof mass is inherently unstable (Sivrioglu 2007). Moreover, since the attractive magnetic force is used to levitate the proof mass, then the effects of nonlinearity for magnetic force in terms of air gap and supplied current, hysteresis and induced eddy current have to be considered (Lin and Jou 1993;Mazenc et al 2006;Eisenover and Martinez 2005;Baloh et al 1999;Yoshimoto 1983;David et al 1996). In order to account for the undesirable uncertainties, a control strategy, such as H-infinity algorithm (Duan and Howe 2003), adaptive tuning (Jeng 2000) or sliding mode loop (Lee et al 2003), is necessary.…”

Section: Introductionmentioning

confidence: 99%

Magnetic actuator design for single-axis micro-gyroscopes

2009

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An innovative magnetically levitated system design is presented in this paper. The proof mass, used as the seismic detection components for gyroscopes, is levitated by the presented micro-coil actuator so that the concerns that mechanical fatigue, asymmetry and misalignments, which are inevitably present in the traditional mechanical springs design, can be ruled out. In addition, the limited range of dual-axis motion of the proof mass is completely relaxed and therefore the resolution and sensitivity of the gyroscope can be greatly upgraded. That is, the proof mass can be much at higher frequencies and the stroke of the sense-mode motion can be more enlarged, in comparison with the conventional design (i.e., mechanical springs). In addition, self-sensing technique is employed to replace the gap sensors which provide the feedback signal for position regulation of the proof mass, for the sake of cost-down for mass production. A sliding mode control strategy is included to account for the effects of nonlinearity of the maglev system dynamics and hysteresis uncertainty of the micro-coil actuator. The proposed controller is verified by computer simulations and experiments to illustrate its superior capability to stabilize the inherently unstable maglev system and ensure fast response for the lateral position regulation of the seismic proof mass.

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Self–Sensing Magnetic Bearings

Maslen

2009

Magnetic Bearings

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An augmented circuit model for magnetic bearings including eddy currents, fringing, and leakage

Cited by 54 publications

References 9 publications

Frequency dependent impedance model for heteropolar magnetic bearings

Frequency dependent impedance model for heteropolar magnetic bearings

Magnetic actuator design for single-axis micro-gyroscopes

Self–Sensing Magnetic Bearings

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