Using Electrical Measurements To Determine The Self-Field Ac Losses Of Cable Models

The self-geld ac losses of HTS cable models have been measured electrically. A non-uniform distribution of the apparent critical currents of tapes was found, indicating variations in terminal resistances and tape degradation during winding. This meant careful consideration was required in the placing of the voltage leads for loss measurements. Single-layer cable losses followed those of an equivalent superconducting tube. The losses of a cable with two layers were lower than the tube prediction. This is explained by taking account of the non-zero lay angle of the tapes.