HTS Pancake Coils Without Turn-to-Turn Insulation.

Area of Science:

• Materials Science
• Electrical Engineering
• Superconductivity

Background:

• High-temperature superconducting (HTS) coils are crucial for advanced technologies.
• Traditional HTS coils utilize turn-to-turn insulation, which can limit performance.
• No-insulation (NI) winding is an alternative approach to HTS coil construction.

Purpose of the Study:

• To investigate the performance of HTS pancake coils fabricated using no-insulation (NI) winding.
• To evaluate the electrical and thermal stability of NI HTS coils under various conditions.
• To compare the performance of NI HTS coils with conventionally insulated coils.

Main Methods:

• Fabrication of three NI pancake coils: two using Bi2223 conductor (single and double pancake) and one using ReBCO conductor.
• Verification of an equivalent electrical circuit model for NI coils through charge-discharge and sudden discharge tests.
• Performance of an overcurrent test with a current 2.3 times the critical current.

Main Results:

• The equivalent electrical circuit model accurately represented NI coil behavior.
• NI HTS coils exhibited enhanced thermal stability compared to conventional coils.
• Overcurrent testing demonstrated the superior stability of NI HTS coils.
• NI winding improved overall current density, thermal stability, and mechanical integrity.

Conclusions:

• No-insulation (NI) winding is a viable technique for fabricating high-performance HTS coils.
• NI HTS coils offer significant advantages in current density, thermal stability, and mechanical integrity.
• This winding method paves the way for more robust and efficient superconducting devices.