HTS thick film components for fault current limiter applications

Fault current limiters are potentially one of the first applications of HTS materials in the power engineering field, and both inductive and resistive devices are being actively developed by many groups world-wide. A wide range of HTS materials is being considered for these devices including biaxially textured planar YBCO films, BSCCO silver clad wires, and textured bulk BSCCO and YBCO. Each type of device has its own particular requirements and restrictions with respect to acceptable component geometries, but the important physical property requirements of the materials appear to be similar in both cases. ALSTOM Research and Technology Centre is building a model current limiter based on an inductive design requiring superconducting components in the form of thick film materials on ceramic substrates. In this paper the design requirements for the current limiter are considered and the development and characterisation of the YBCO thick film materials for the device are reported. In particular, the property and performance issues concerning the scale-up of component sizes required for the demonstrator device are discussed. Preliminary results of the behaviour of the thick film components in an inductive FCL environment are also reported.