Self-Protection Characteristic Comparison between No-Insulation, Metal-as-Insulation, and...

Area of Science:

• Superconducting magnet technology
• Materials science
• Electrical engineering

Background:

• The metal-as-insulation (MI) winding method enhances mechanical properties and reduces current density in high-field REBCO magnets.
• However, MI winding increases inter-turn resistance, known as characteristic resistance, potentially hindering magnet protection during abnormal events like quenches.

Purpose of the Study:

• To introduce and evaluate the surface-shunted-metal-as-insulation (SSMI) winding method.
• To compare the characteristic resistances and self-protecting characteristics of NI, MI, and SSMI winding methods.

Main Methods:

• Developed the SSMI winding technique by adding a shunt to the MI winding surface.
• Fabricated single pancake coils using no-insulation (NI), MI, and SSMI methods with a consistent winding pressure of 20 N.
• Measured and compared characteristic resistances and analyzed self-protecting behaviors.

Main Results:

• The SSMI method was shown to effectively reduce the characteristic resistance compared to the standard MI winding.
• The study presents comparative test results for single pancake coils under identical winding pressures.
• Investigated the specific impact of the SSMI method on characteristic resistance values.

Conclusions:

• The SSMI winding method offers a promising solution to mitigate the increased characteristic resistance associated with MI winding.
• This technique potentially allows for the combined advantages of MI and NI winding, improving magnet protection capabilities.
• Further research is warranted to fully explore the self-protecting characteristics of SSMI coils in high-field magnet applications.