Fault current limitation in grids of power plants using resistive HTS current limiter

摘要

Short-circuit currents in grids (medium-voltage and low-voltage level) of power plants reach high values because of infeeding transformers with high power and a large amount of induction machines which feed the short-circuit currents too. Therefore switchgears and appliances with a high short-circuit withstand capability have to be applied. A possible way to reduce these high stresses is the application of current limiters. There already exist different types of current limiters, but most of them, which limit the short-circuit current by an immediate interruption, are not applicable because the effects on grid operation and protection concept are enormous. Resistive high temperature superconducting (HTS) fault current limiters seem to be proper appliances because they permit the adjustment of the limited short-circuit currents and the limitation duration. In this paper some results of basic investigations concerning the requested limitation parameters are shown. The work illustrates that the fault current limitation must be treated as a complex task of coordinated system configuration.