Study on the Electrical Contact Resistance Properties With Various Winding Torques for Noninsulated HTS Coils

Kim, S. B.; Kajikawa, Hiroshi; Ikoma, Hideaki; Joo, Jin-Hong; Jo, Jeong-Min; Han, Young Jae; Jeong, Hyun-Seung

doi:10.1109/tasc.2013.2283103

Cited by 4 publications

(3 citation statements)

References 10 publications

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“…Therefore, the experimental results validate the simulated results. An HTS coil with a resistance of 1µΩ [21] (Q > 10000) is currently being constructed and based on the above experimental results, it is expected that better results can be obtained than those shown in Figs. 3(c) & 3(d), and Table II.…”

Section: A Experimental Setupmentioning

confidence: 98%

“…Recently, a High Temperature superconductor (HTS) reactor with almost zero resistance has been manufactured. In [17] - [21], the features of a typical HTSR including physical parameters, electro-magnetic properties, and operating temperature are described. In [22], it is suggested that a cryogenic cooling system is required in an HTSR to handle the temperature.…”

Section: Introductionmentioning

confidence: 99%

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Protecting PFC Capacitors from Overvoltage Caused by Harmonics and System Resonance Using High Temperature Superconducting Reactors

Islam

Sutanto

Muttaqi

2019

IEEE Trans. Appl. Supercond.

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Shunt capacitors are deployed for power factor correction (PFC) to reduce the load reactive power and to provide voltage support. Nonlinear loads, such as variable speed drives, can inject harmonics into the network. If the line impedance value produces a resonance with the PFC capacitor and the injected frequency coincides with the resonant frequency, an overvoltage is produced across the capacitor, which can lead to failure or explosion. To protect the PFC capacitor, a reactor can be connected in series with the PFC capacitor and tuned at the harmonic frequency of the system resonance. This paper proposes the use of a high temperature-superconducting reactor (HTSR) as the tuned reactor. The reactor will have an extremely high-quality factor (Q) compared to the normal reactor that can never be manufactured commercially with such a high Q. The performance of the HTSR reactor in terms of its ability to protect the capacitor from overvoltage and to reduce power losses has been investigated. The results are compared with those using the conventional (low Q) reactor and show that the HTSR can significantly improve filter performance and reduce power losses in the filter.

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Section: A Experimental Setupmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

Protecting PFC Capacitors from Overvoltage Caused by Harmonics and System Resonance Using High Temperature Superconducting Reactors

Islam

Sutanto

Muttaqi

2019

IEEE Trans. Appl. Supercond.

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“…When the HTS coil is applied to rotating machine, it is difficult to install the quench detector and protection device to the rotating machine. So, we have been developing the new self -protection methods, removing insulation between layer-to-layer winding and inserting various metal tapes (Cu, Ni, Stainless and/or Brass) instead of the insulation [1][2][3]. When operate current to the coil, voltage is generated by the sweep rate of the current (di/dt) and the inductance of the coil.…”

Section: Introductionmentioning

confidence: 99%

Development of the Current Bypassing Methods into the Transverse Direction in Non-insulation HTS Coils

et al. 2015

Self Cite

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In the case of motors and generators, the benefits of using high temperature superconducting (HTS) coils can be represented by the reduction of 50% in both losses and sizes compared to conventional machines. However, it is hard to establish quench detection and protection devices for the HTS coils applied to the rotors of motors and generators. So, the stability of the coils is lower than for the quiescent coils applied to NMR, MRI and so on. Therefore, it is important to improve the self-protection ability of HTS coils. We have studied the methods to improve the self-protection ability of HTS coils by removing the layer-to-layer insulation and inserting metal tape instead of the electrical insulation. The operating current in the non-insulated HTS coil was bypassed into the transverse direction by the generated normal region because of their electrical contact among the winding. In this study, we examined the method to control the current bypassing on layer-to-layer for controlling the inductance of the non-insulated HTS coil. The current bypassing properties on non-insulated HTS coil wound with 2G wires will be discussed.

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Investigation of traction motor windings' insulation capacitance at switching frequencies under accelerated thermal stress

Panagiotou

Gyftakis

Lophitis

et al. 2017

2017 IEEE 11th International Symposium on Diagnostics for Electrical Machines, Power Electronics and Drives (SDEMPED)

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Machines in electric vehicles are driven by switching power electronic devices and undergo variable load cycling. In transient conditions high currents and temperatures develop, forcing the electric motor and particularly the insulation materials to undergo severe multi-stress. Insulation degradation will progressively lead to short-circuits which are harmful for the traction motor, vehicle safety and reliability. This paper focuses on the thermal assessment of insulation's capacitance at switching frequencies. For this, thin-film winding insulation samples were thermally aged at different temperatures and for various periods of time. Dielectric spectroscopy was applied and the capacitance information at different frequencies was extracted. The measurements were substituted to statistical analysis under three factors namely; ageing time, temperature and frequency. It is also evaluated how appropriate it is to use capacitance measurements as a means for reliable prognostic method. The statistical analysis depicts that the capacitance does not follow predictable ageing patterns, mainly because the material's dielectric properties are affected by a number of different degradation mechanisms that occur concurrently.

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Study on the Electrical Contact Resistance Properties With Various Winding Torques for Noninsulated HTS Coils

Cited by 4 publications

References 10 publications

Protecting PFC Capacitors from Overvoltage Caused by Harmonics and System Resonance Using High Temperature Superconducting Reactors

Protecting PFC Capacitors from Overvoltage Caused by Harmonics and System Resonance Using High Temperature Superconducting Reactors

Development of the Current Bypassing Methods into the Transverse Direction in Non-insulation HTS Coils

Investigation of traction motor windings' insulation capacitance at switching frequencies under accelerated thermal stress

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