Strain-based quench detection for a solenoid superconducting magnet

Abstract

In this paper, we present a non-electric quench detection method based on the strain gauge measurement of a superconducting solenoid magnet at cryogenic temperature under an intense magnetic field. Unlike the traditional voltage measurement of quench detection, the strain-based detection method utilizes low-temperature strain gauges, which evidently reduce electromagnetic noise and breakdown, to measure the magneto/thermo-mechanical behavior of the superconducting magnet during excitation. The magnet excitation, quench tests and trainings were performed on a prototype 5 T superconducting solenoid magnet. The transient strains and their abrupt changes were compared with the current, magnetic field and temperature signals collected during excitation and quench tests to indicate that the strain gauge measurements can detect the quench feature of the superconducting magnet. The proposed method is expected to be able to detect the quench of a superconducting coil independently or utilized together with other electrical methods. In addition, the axial quench propagation velocity of the solenoid is evaluated by the quench time lags among different localized strains. The propagation velocity is enhanced after repeated quench trainings.

A Novel Fault Diagnosis Method for High-Temperature Superconducting Field Coil of Superconducting Rotating Machine

“…Sci. 2020, 10, x FOR PEER REVIEW 2 of 11 [2,3], telemetry [4], and strain gauges [5,6]. A universal quench detection technique was proposed by Nanato et al with active power detection using a central voltage tap [7,8].…”

“…Therefore, thermal runaway can occur in a hot spot and damage the HTS coil due to stored magnetic energy before the resistance generated in the normal zone can be measured. For these reasons, various quench detection methods that do not use a traditional voltage tap have been studied [1][2][3][4][5]. Ravaioli et al proposed a quench detection method based on the change in stray capacitance between magnet elements when quenching occurred [1].…”

“…In addition, the capacitance monitoring system is temporarily interrupted by circuit transients, which is a drawback in quench detection. Other quench detection methods that do not rely on voltage taps have also been studied, including such as acoustic emission [2,3], telemetry [4], and strain gauges [5,6]. A universal quench detection technique was proposed by Nanato et al with active power detection using a central voltage tap [7,8].…”

Advances in Fiber Optic Sensors Technology Development for Temperature and Strain Measurements in Superconducting Magnets and Devices

“…Several fiber optic technologies have been investigated for their use in magnets or other devices with distributed [1] or multi point sensing scheme [2]. Among them, FBG based sensors seem one of the most promising technology for cryogenic temperatures monitoring [3][4][5][6] along with Rayleigh scattering based sensors . This paper reports on the feasibility of the use of FBG sensors, in embedded configuration, for the cable local temperature and strain monitoring, when integrated for the first time inside impregnated Nb3Sn coil in a subscale dipole magnet called SMC (Short Model Coil) fabricated at CERN.…”

Flux avalanche in a superconducting film with non-uniform critical current density

“…There is high thermal strain in the superconductor induced by the temperature change. Wang et al [25] proposed a method to detect the quench in superconductors via experimental observation of the thermal strain. In addition, the electromagnetic response in superconductors has been studied widely.…”