Design, Assembly, and Commissioning of a Cryogenic DC Current Transformer Designed for Measuring Currents of up to 80 kA

Abstract

A new cryogenic dc current transformer (Cryo-DCCT) has recently been designed and assembled at CERN. The device, whose design is based on that of a high-accuracy 600 A market solution suitable for room temperature applications, is optimized for measuring currents of up to 80 kA and for operation at 4.2 K. The CryoDCCT has been conceived with the objective of preserving the metrological performance of the original commercial device in the new extended range of operation. For reducing the effect of interfering magnetic fields arising from test conditions, it incorporates ferromagnetic and MgB2 superconducting shields. In this paper, the design of the CryoDCCT and the results of the commissioning of the device at CERN are reported. The effectiveness of the current transducer is analysed and discussed. This new device will be used for measuring the secondary current of a 80 kA superconducting transformer feeding a sample of NbSn3 cable at the Facility for Research on Superconducting Cables (FRESCA) at CERN.

Research on a Composite Voltage and Current Measurement Device for HVDC Networks

“…The obtained measurement accuracy is higher than the noncontact voltage transformer method reported in [32] and the electronic current transformer method presented in [33]. It is worth mentioning that conventional devices can only perform one measurement task for either voltage or current which calls for two transformers and two insulating bushings to perform simultaneous voltage and current measurements.…”