Fundamental limitations in self-sensing magnetic bearings when modeled as linear periodic systems

Peterson, Kevin J.; Middleton, Richard H.; Freudenberg, J.S.

doi:10.1109/acc.2006.1657437

Cited by 8 publications

(4 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…4 shows the result of the inductance value of the EMA measured with LCR meter compared to the theoretical result in Eq. (8). As shown in Fig.…”

Section: Compensation Of the Theoretical Inductancementioning

confidence: 89%

“…This was suggested by Okada et al [3]. However, since the current ripples corresponding to PWM carrier frequency may also be changed by duty ratio, it is necessary to take the duty ratio into the consideration for the controller design by measuring voltage ripples [4,5] or using a nonlinear observer [6,7,8]. For improved position accuracy, magnetic material permeability can be compensated by using an approximated static permeability curve [9,10].…”

Section: Introductionmentioning

confidence: 98%

See 1 more Smart Citation

A self-sensing technology of active magnetic bearings using a phase modulation algorithm based on a high frequency voltage injection method

Park

Han

Park³

et al. 2008

J Mech Sci Technol

View full text Add to dashboard Cite

Conventional AMB(active magnetic bearings) systems consist of electromagnetic coils, position sensors, power amplifiers and a feedback controller. This hardware configuration can lead to a structural complexity, problems of space limitations for the installation, and position control difficulties due to the non-collocation of actuators and sensors. In this paper, a self-sensing mechanism is proposed to resolve such limitations of the general AMB system. The proposed self-sensing scheme uses a phase difference of the injected current of two opposite electromagnetic actuators while an object is levitating between the actuators. The relationship between the phase difference of injected currents and the position of a levitated object was theoretically derived and linearized. In order to realize the proposed self-sensing scheme, a signal processing algorithm was developed. The frequency response of the estimator was measured to verify the performance of the proposed self-sensing scheme. In addition, a magnetic levitation and a disturbance rejection response were experimentally obtained to verify the feasibility of the proposed self-sensing mechanism. Experimental results showed that the developed self-sensing technique has similar performance as a practical gap sensor.

show abstract

“…4 shows the result of the inductance value of the EMA measured with LCR meter compared to the theoretical result in Eq. (8). As shown in Fig.…”

Section: Compensation Of the Theoretical Inductancementioning

confidence: 89%

Section: Introductionmentioning

confidence: 98%

A self-sensing technology of active magnetic bearings using a phase modulation algorithm based on a high frequency voltage injection method

Park

Han

Park³

et al. 2008

J Mech Sci Technol

View full text Add to dashboard Cite

show abstract

“…As a result, variation of coil resistance, mentioned earlier as a problem in the speed electromotive force-based method, can be ignored. Stability of this method was analyzed using sensitivity function in a linear periodic system [9,10], indicating that sensitivity can be reduced by superimposing voltage.…”

Section: Introductionmentioning

confidence: 99%

“…High-frequency voltage superimposed on electromagnets can be generated with the sine voltage [10], the carrier of pulse width modulation (PWM) amplifier [11], and the hysteresis amplifier [12]. Regarding gap calculation, there are methods based on amplitude demodulation and phase demodulation [13].…”

Section: Introductionmentioning

confidence: 99%

Unscented Kalman Filtering for Self‐Sensing Magnetic Levitation against Magnetic Saturation

Matsuda

Sakamoto

2016

Electrical Engineering Japan

View full text Add to dashboard Cite

SUMMARYThis paper investigates the magnetic saturation problem of self-sensing electromagnetic levitation system and presents a novel self-sensing scheme. The proposed approach employs a demodulation technique. By superimposing a high-frequency voltage, the resulting electromagnet coil currents have ripples that can be used for gap sensing. This paper shows that the gap length is not uniquely estimated when using only the relation between the ripple, the control currents, and the gap. The constraint conditions are to be determined to solve the problem. The proposed approach utilizes the dynamical motion model of the electromagnetic levitation system to uniquely identify the gap. Introducing the system behavior dynamics, the gap can be exactly estimated. To incorporate the system model with the gap sensing algorithm, a nonlinear filtering methodology is employed. The proposed estimator is demonstrated by the experiments. The results show that it is possible to address magnetic saturation with the proposed gap sensing scheme. The estimator has a good accuracy in a wider gap range compared to the conventional methods. C⃝ 2016 Wiley Periodicals, Inc. Electr Eng Jpn, 196(4): 60-68, 2016; Published online in Wiley Online Library (wileyonlinelibrary.com).

show abstract

Self–Sensing Magnetic Bearings

Maslen

2009

Magnetic Bearings

View full text Add to dashboard Cite

Fundamental limitations in self-sensing magnetic bearings when modeled as linear periodic systems

Cited by 8 publications

References 16 publications

A self-sensing technology of active magnetic bearings using a phase modulation algorithm based on a high frequency voltage injection method

A self-sensing technology of active magnetic bearings using a phase modulation algorithm based on a high frequency voltage injection method

Unscented Kalman Filtering for Self‐Sensing Magnetic Levitation against Magnetic Saturation

Self–Sensing Magnetic Bearings

Contact Info

Product

Resources

About