Superconductivity is an electrical resistance of exactly zero,occurring in certain materials below a characteristic temperature. It was discovered by Heike Kamerlingh Onnes in 1911.

High Tc superconductor, which has superconducting properties in liquid nitrogen temperature, was discovered in 1986. The many promising HTS applications include electric power transmission,transformers, power storage devices, electrical generators, and fault current limiters in a high-performance smart grid. HTS is also expected to use electric motors and magnetic levitation devices as in-vehicle propulsion, ship propulsion, and Maglev trains.