Zero-sequence current blocking device for two phase AC systems

Stefan Christian Polster, Dennis Albert, Herwig Renner, Robert Schürhuber, Clemens Obkircher, Georg Rader

Research output: Contribution to conferencePaperpeer-review


Resonantly grounded power systems require fault current limitation in order to meet current standards and to ensure personal safety. A current limiting transformer (CLT), based on an isolating transformer, is investigated here. The major advantages of a CLT, compared to an isolating transformer, are power derating, reduction of leakage reactance and thus reduced losses and reactive power demand during operation. MATLAB/Simulink® is used to investigate the electrical behavior of the CLT. Simulations of a phase-to-ground fault are made to proof the reduction of fault currents. Modelling the CLT in symmetric components demonstrates the blocking mechanism for the zero-sequence currents. In this context special attention has to be paid to resonant currents in resonantly grounded networks, when using the CLT.
Original languageEnglish
Number of pages4
Publication statusPublished - 3 Sept 2019
Event54th International Universities Power Engineering Conference - Bucharest, Romania
Duration: 3 Sept 20196 Sept 2019


Conference54th International Universities Power Engineering Conference
Abbreviated titleUPEC 2019
Internet address


  • current limiters
  • fault currents
  • power systems
  • power transmission
  • transformers


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