&lt;b&gt;Monitoring and Protection Method of a REBCO Magnet Designed for Electromagnetic Vibration Tests&lt;/b&gt;

Mizuno, Katsutoshi; Tanaka, Minoru; Ogata, Masafumi

doi:10.2219/rtriqr.61.1_60

Cited by 5 publications

(6 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The spindle vibration monitoring system of NC biomedical machine tool generally adopts the classical signal processing method based on stationary process, which is difficult to accurately describe the local characteristics with strong nonstationarity caused by working condition changes or faults. Therefore, the spindle vibration monitoring system of NC biomedical machine tool needs to be able to monitor not only the time domain waveform and frequency domain characteristic quantity of vibration signal, but also the time-frequency characteristic quantity that can reflect the local characteristics of vibration signal [31,32].…”

Section: Software Design Of Monitoring Systemmentioning

confidence: 99%

Mechanical vibration monitoring system for electrocardiogram machine based on Hilbert‐Huang transformations

Zhu

Samori

2022

The Journal of Engineering

View full text Add to dashboard Cite

The monitoring of health and the technologies that are related to it are an exciting area of research. The paper proposes a mechanical manufacturing vibration monitoring system that is based on Hilbert-Huang transformation (HHT) feature extraction to monitor the running state of the spindle of a mechanical numerical control (NC) machine tool of an electrocardiogram (ECG) machine. Real-time monitoring of the time-frequency characteristic quantity of the spindle vibration signal for ECG signals has been made possible due to the online empirical mode decomposition (EMD) method, which is used to obtain the time-frequency characteristic quantity of the spindle vibration signal based on HHT. The experiment shows that the frequency doubling characteristic components in the timefrequency distribution are obvious in the time interval without copper rod contact, but they disappear in the time interval during which copper rods are in contact (0.3 1.1 s, 3 4s in the figure). It has been demonstrated that the system is capable of not only accurately monitoring the characteristic quantity in the frequency domain of the vibration signal produced by the NC machine tool spindle, but also of successfully implementing the monitoring of the time-frequency characteristic quantity in real time.

show abstract

Section: Software Design Of Monitoring Systemmentioning

confidence: 99%

Mechanical vibration monitoring system for electrocardiogram machine based on Hilbert‐Huang transformations

Zhu

Samori

2022

The Journal of Engineering

View full text Add to dashboard Cite

show abstract

“…Therefore, an automated early detection of the malfunctions and shut down of the excitation power supply are indispensable for long-term REBCO magnet operation. The normal transition detection based on coil voltage monitoring was proposed in our previous study [6]. Since the voltage of the normal transition is infinitesimal in the early stages, voltage noise reduction method is essential.…”

Section: Voltage Noise In the Rebco Coil From The Ground Coilmentioning

confidence: 99%

“…The maximum noise amplitude is 16 mV. In a thermal runaway test using a small REBCO coil [6], detection level of 0.5 mV was required to prevent the burn-out of coil. The normal voltage of 0.5 mV is easily buried in the noise, so that detection is impossible.…”

Section: Voltage Noise Measurement Of the Rebco Coilmentioning

confidence: 99%

“…Therefore, pancake coils in bilaterally symmetric position have not only the same mutual inductance but also the same magnetic flux distribution. For that reason, the difference of the pancake coil voltages cancels the noise due to the excitation power supply and shielding current [6]. The shielding current is a loop current inside the superconducting layer of the REBCO coated conductor caused by fluctuating magnetic field.…”

Section: Noise Canceling Mechanismmentioning

confidence: 99%

See 1 more Smart Citation

<b>Voltage Noise Measurement of a REBCO Superconducting Coil During Electromagnetic Vibration Tests on a Ground Coil</b>

2021

Self Cite

View full text Add to dashboard Cite

In electromagnetic vibration tests, a ground coil is excited under the strong magnetic field of a superconducting magnet. Since the vibration mechanisms in the test are the same as for actual maglev (magnetic levitation) running conditions, electromagnetic vibration tests are therefore an important durability test for ground coils. We carried out electromagnetic vibration tests with a superconducting magnet with REBCO wire, which is a high-temperature material. This paper also proposes a novel monitoring and protection method for REBCO magnets.

show abstract

“…It is not surprising therefore that the * Author to whom any correspondence should be addressed. coated superconductor is deemed to be a promising element for applications of high field magnets [4,5], magnetic resonance imaging [6,7], magnetic levitation [8,9] and electrical machines [10,11]. Among the multiple design options for coated superconductor coils to meet the practical demands of the aforementioned applications, two insulation approaches have been widely adopted so far.…”

Section: Introductionmentioning

confidence: 99%

Thermo-electromagnetic modeling of coated superconductor coils with metal insulation

Wang

Zhou

et al. 2021

Supercond. Sci. Technol.

View full text Add to dashboard Cite

The use of metallic sheets as the insulator in a coated superconductor coil is able to increase its turn-to-turn contact resistance for shortening the charging/discharging delay while preserving the self-protection ability. To theoretically understand and predict the properties of the metal-insulation coils, we developed a thermo-electromagnetic model, in which a modified equivalent circuit for electrically representing the metal-insulation coils is built to take the effect of insulator into account. The effectiveness and versatility of this model are verified by different experimental scenarios, e.g., charging, sudden-discharging, and overcurrent. Enabled by the validated model, we carried out a set of case studies and observed that, (a) the metal-insulation coil with a low resistivity and high thermal conductivity metallic insulator is preferable to achieve a better thermal stability; (b) there exists an optimal insulator thickness for realizing the shortest charging delay, but a thicker insulator is superior for realizing a stronger thermal stability; (c) contact resistivity of over 104 μΩ· cm2 can weaken the current sharing in the radial direction, which would deteriorate the thermal stability of the metal-insulation coils, although it can significantly suppress the charging delay, implying that a tradeoff is always needed to balance the charging delay and thermal stability when determining the contact resistivity. These findings, mostly being inaccessible from the experiments, provide guidance toward practical applications of metal-insulated coated superconductor coils.

show abstract

<b>Monitoring and Protection Method of a REBCO Magnet Designed for Electromagnetic Vibration Tests</b>

Cited by 5 publications

References 4 publications

Mechanical vibration monitoring system for electrocardiogram machine based on Hilbert‐Huang transformations

Mechanical vibration monitoring system for electrocardiogram machine based on Hilbert‐Huang transformations

<b>Voltage Noise Measurement of a REBCO Superconducting Coil During Electromagnetic Vibration Tests on a Ground Coil</b>

Thermo-electromagnetic modeling of coated superconductor coils with metal insulation

Contact Info

Product

Resources

About