HTS cable test facility: design and initial results

A versatile, high-temperature superconducting (HTS) cable test facility has been designed and assembled at Oak Ridge National Laboratory (ORNL) in a joint program between ORNL and Southwire Company. The facility mission is to evaluate the performance of prototype HTS power transmission cables at lengths in the range of 1 to 5+ m. Power supplies are available for steady-state currents of 3000 A (DC) and 2000 A (AC) as well as up to 25000 A (DC) for pulsed loading. Cryogenic cooling is provided by an Air Products liquid nitrogen supply system with the capability of providing about a kilowatt of cooling at pressures up to 10 bar over a temperature range of about 67 to 77 K. Electrical and cryogenic data are taken by dedicated sensors scanned by ten-channel multimeters connected via cable and fiber optic to a personal-computer-based, data acquisition system using the LabVIEW program. These diagnostics allow measurement of the DC V-I characteristics and AC loss of the cable, dielectric integrity via a partial discharge measurement, and cryogenic performance at rated voltage (7.2-kV AC) and current (1250 A). Initial results from facility commissioning and early HTS cable testing are reported,.