A Noninductive Bifilar Coil to Design Compact Flux Pumps for HTS Magnets

Abstract

High temperature superconducting flux pump is a promising way of energizing superconducting magnets without direct electrical contacts. It can remove the resistive heating and heat leakage from the current leads at room temperature. It is well known that applying the current over the critical current of the superconductor, will force the superconducting layer to enter into the flux flow regime. This flux flow resistivity generates a dc voltage across the length of the HTS tape. This phenomenon is well understood , however, it is difficult to generate a high dc charging voltage without a high current. In this work, we demonstrate a novel flux pumping technique by using a noninductive bifilar bridge wound in parallel to the HTS coil. This configuration can generate large dc voltages using relatively small currents. It results in effectively pumping dc currents equal to the critical current for large HTS magnets.

Miniaturized HTS linear flux pump with a charging capability of 120 A

“…A flux pump usually refers to a device that eliminates bulky current leads and indirectly injects current into the superconducting coil, which is a promising power source for HTS coils [9][10][11][12]. Recently, HTS flux pumps have received a lot of attention, such as transformer-rectifier flux pumps [13][14][15][16][17] and traveling wave flux pumps [18].…”

Effective circuit modelling and experimental realization of an ultra-compact self-rectifier flux pump

“…Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. asymmetric, alternating input current of a transformer to generate the dc current through a superconducting load [2][3][4][5][6][7]. Rectification is achieved by driving current larger than the critical current, I c , through part of the superconducting circuit (the 'bridge') for part of the input waveform cycle.…”