Test results for laboratory scale inductive high-Tc superconducting fault current limiters

Several laboratory scale screened iron core superconducting fault current limiters (<1 kVA nominal rating) have been built and tested in order to study their fault current limitation characteristics. In this article we present the experimental results for a static impedance test and for a dynamic short circuit test. The static test is used to define the device operating conditions and the dynamic short circuit test is used to characterize the limiter´s performance. With the superconducting limiter in the test circuit, short circuit fault currents are limited to a few times the nominal current. The device impedance shows an initial rapid response followed by a more gradual increase over the first few cycles of fault current. Using a simplified circuit model analysis the experimental results are used to deduce materials parameters such as the superconductor current density and resistivity. The development prospects for high-T_c superconducting fault current limiters are discussed