About the quasistationary behaviour during a short circuit between different voltage levels

Understanding the systems behaviour during a short circuit between different voltage levels is essential to design a protection system capable to clear also these faults efficiently. With a power systems calculation program it is possible to study such cases, if its algorithm allows the input of these special fault types, if the power system is modelled accordingly and if all required data are available. The first two parts of this paper are based on the corresponding dissertation [1] presented by the author at the Swiss Federal Institute of Technology Zurich.