Experimental Investigation of the Model of Superconducting Transformer With the Windings Made of 2G HTS Tape

Abstract

Recently developed 2G superconducting tapes with high resistivity in the normal state at a temperature of 77 K allow us to build transformers with high short-circuit strength. High resistance of the HTS windings in the normal state causes the limitation of short-circuit current to the level depend on the value of that resistance. Rapid limitation of the short-circuit current can be achieved and the steady-state fault current can be limited to a value resulting mainly from the parameters of HTS tapes used. The required reduction of prospective fault current in a power grid can be achieved by installing in it a superconducting transformer with a winding made of 2G HTS tape only if the tape provides proper resistance-per-length in normal state at a temperature of 77 K. This article presents the results of an experimental investigation of a 1-phase model of a superconducting transformer, with special regard to the possibility of limiting the short-circuit current by the superconducting winding, according to the parameters of the HTS tapes used, in particular their resistivity in normal state at a temperature of 77 K.