Friday, January 13, 2012
Superconducting current limiter guarantees electricity supply of the Boxberg power plant: Below a temperature of 90° Kelvin or minus 183° Celsius, the material becomes superconductive. However, superconductivity collapses abruptly when the current in the conductor exceeds the design limits. This effect is used by the current limiter. In case of current peaks in the grid, the superconductor loses its conductivity within fractions of a second and the current will flow through the stainless steel strip only, which has a much higher resistance and, thus, limits the current. The heat arising is removed by the cooling system of the superconductor. A few seconds after the short circuit, it is returned to normal operation in the superconducting state. YBCO superconducting layers on stainless steel strips are more stable and operation-friendly than first-generation superconductors based on BSCCO ceramics.