Study on Hot-Spot Temperature Limits for YBCO Epoxy-Impregnated Coil to be Safe From Damages Caused by Quenches

Ariyama, Takahiro; Takagi, Toshihisa; Takao, T.; Tsukamoto, O.; Matsuo, Ryuta; Matsuda, Naohiro

doi:10.1109/tasc.2016.2625699

Cited by 12 publications

(5 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This sample was also damaged. As shown in Figure 7, the peak temperatures of the two damaged samples were both around 530 K. This observation is consistent with [40][41][42]. In other words, this threshold temperature determines the possibility of recovery.…”

Section: Discussionsupporting

confidence: 81%

Investigations on Quench Recovery Characteristics of High-Temperature Superconducting Coated Conductors for Superconducting Fault Current Limiters

et al. 2021

View full text Add to dashboard Cite

Superconducting fault current limiters (SFCLs) are attracting increasing attention due to their potential for use in modern smart grids or micro grids. Thanks to the unique non-linear properties of high-temperature-superconducting (HTS) tapes, an SFCL is invisible to the grid with faster response compared to traditional fault current limiters. The quench recovery characteristic of an HTS tape is fundamental for the design of an SFCL. In this work, the quench recovery time of an HTS tape was measured for fault currents of different magnitudes and durations. A global heat transfer model was developed to describe the quench recovery characteristic and compared with experiments to validate its effectiveness. Based on the model, the influence of tape properties on the quench recovery time was discussed, and a safe margin for the impact energy was proposed.

show abstract

Section: Discussionsupporting

confidence: 81%

Investigations on Quench Recovery Characteristics of High-Temperature Superconducting Coated Conductors for Superconducting Fault Current Limiters

et al. 2021

View full text Add to dashboard Cite

show abstract

“…As shown in figure 19(c), the peak of the maximum temperature inside the winding was 330 K, which is lower than a reported temperature causing degradation (>500 K) for a paraffin impregnated REBCO coil [39]. As shown in figure 21(a)-5, the peak temperature located at the uppermost turn of the 89th layer, which was the quench origin turn.…”

Section: Quench Simulation Modelmentioning

confidence: 73%

“…the coil will be mechanically damaged. In the case of ρ ct = 25 000 µΩ cm 2 , T peak is higher than the temperature causing the degradation [39], i.e. the coil will be thermally degraded.…”

Section: Effects Of Lower Contact Resistivity On the Quench Propagati...mentioning

confidence: 97%

Quench and self-protecting behaviour of an intra-layer no-insulation (LNI) REBCO coil at 31.4 T

Suetomi

Yoshida

Takahashi

et al. 2021

Supercond. Sci. Technol.

View full text Add to dashboard Cite

This paper presents experimental results on a quench of an intra-layer no-insulation (LNI) (RE: rare earth)Ba2Cu3O7−δ (REBCO) coil in a 31.4 T central magnetic field and simulated results on the quench. We have been designing a persistent-mode 1.3 GHz (30.5 T) nuclear magnetic resonance (NMR) magnet with a layer-wound REBCO inner coil. Protection of the REBCO coil from quench is a significant issue and the coil employs the LNI method to obtain self-protecting characteristics. We conducted high-field generation and quench experiments on an LNI-REBCO coil connected to an insulated Bi2Sr2Ca2Cu3O x (Bi-2223) coil under a background magnetic field of 17.2 T as a model of the 1.3 GHz NMR magnet. The coils successfully generated a central magnetic field of 31.4 T. Although the LNI-REBCO coil quenched at 31.4 T, this quench did not cause any degradation to the coil. A numerical simulation showed the current distribution during the quench was non-uniform and changed rapidly over time due to current bypassing through copper sheets between layers, resulting in faster quench propagation than in an insulated REBCO coil. During the quench propagation, the peak temperature (T peak) and the peak hoop stress BzJR (σθ, peak) were calculated to be 330 K and 718 MPa, respectively. These are below critical values that cause degradation. The simulation also showed that the high electrical contact resistivity (ρ ct) of 10 000 µΩ cm2, between REBCO conductors and copper sheets in the LNI-REBCO coil winding, played an important role in protection. When ρ ct was as low as 70 µΩ cm2, the quench propagation became too fast and large additional currents were induced, resulting in an extremely high σθ, peak of 1398 MPa, while the T peak was as low as 75 K. In short, the high ρ ct in the present coil caused a high T peak, but succeeded in suppressing σθ, peak and protecting the coil from the quench.

show abstract

“…During thermal run-away, T HS exceeds T HSs and the coil is damaged. T HSs was estimated by experiments to be 300-400 K [26]. When V q is below V qs , the thermal run-away does not occur and the coil is safe from the quench damage.…”

Section: Comparison Of Basic Detect-and-dump Methods Andmentioning

confidence: 99%

Quench protection system for an HTS coil that uses Cu tape co-wound with an HTS tape

Toriyama

Nomoto

Ichikawa

et al. 2019

Supercond. Sci. Technol.

View full text Add to dashboard Cite

A quench protection system for a high-temperature superconducting (HTS) coil using Cu tape co-wound with an HTS tape was studied by numerical analysis using a thermal model of a coil winding pack. In normal operation, the voltage across the resistive zone Vs in the HTS coil was monitored by measuring the voltage difference between the HTS coil and the co-wound Cu coil. When Vs exceeded the quench detection voltage, the HTS coil was disconnected from the power supply and the energy stored in the HTS coil was dumped into a dump resistor. At the same time, the terminals of the co-wound coil were connected to another resistor, and some of the current in the HTS coil was quickly transferred to the co-wound Cu tape coil due to the tight magnetic coupling of both coils. This is expected to decrease the hot-spot temperature due to the quick decrease of HTS coil current and to protect the coil from damage caused by overheating at the hot-spot. The analysis investigated the effectiveness of this method.

show abstract

Study on Hot-Spot Temperature Limits for YBCO Epoxy-Impregnated Coil to be Safe From Damages Caused by Quenches

Cited by 12 publications

References 8 publications

Investigations on Quench Recovery Characteristics of High-Temperature Superconducting Coated Conductors for Superconducting Fault Current Limiters

Investigations on Quench Recovery Characteristics of High-Temperature Superconducting Coated Conductors for Superconducting Fault Current Limiters

Quench and self-protecting behaviour of an intra-layer no-insulation (LNI) REBCO coil at 31.4 T

Quench protection system for an HTS coil that uses Cu tape co-wound with an HTS tape

Contact Info

Product

Resources

About