Quench Behavior of ${\hbox {Bi}}_{2}{\hbox {Sr}}_{2}{\hbox {Ca}}_{2}{\hbox {Cu}}_{3}{\hbox {O}}_{\rm x}/{\hbox {Ag}}$ Tape With AC and DC Transport Currents and a Comparison With ${\hbox {YBa}}_{2}{\hbox {Cu}}_{3}{\hbox {O}}_{\rm x}$ Conductors

Abstract

When operating in power applications, superconducting conductors often carry alternating currents (AC). Thus, understanding the quench behavior under AC conditions is essential for protecting high temperature superconductor-based devices in power applications. In this work, the quench behavior of Bi <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> Sr <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> Ca <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> Cu <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> /Ag (Bi2223/Ag) tape with AC and DC transport currents is reported. The minimum quench energies and normal zone propagation velocities are measured for different DC and AC transport currents at 45 K. The frequency of the AC transport current is varied from 50 Hz to 400 Hz. AC losses are measured to analyse the background condition of AC quenches. The results are compared with those of a YBa <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> Cu <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> (YBCO) coated conductor that was studied previously with identical conditions.