Abstract

Transformers are a fundamental building block of any AC power distribution system. They convert voltages up or down for long-range transmission or distribution of power to the industrial or household level. Transformers operate using Faraday's law where the input and output voltage and current levels are linked by electromagnetic induction occurring in primary and secondary conductor windings. These windings typically surround a ferromagnetic core, and are separated by a dielectric insulator. Superconductor transformers follow the same basic configuration as conventional transformers [1]. An example of a three-phase HTS transformer is shown in Figure H1.9.1. Between generation and consumption of power in a power grid there may be as many as 5–10 transformers [2]. The AC currents through the transformers will cause losses in both the magnetic core and the windings. The efficiency of the power distribution system therefore relies on transformers being highly efficient.