Short-circuit effects in HV substations with strained conductors-systematic full scale tests and a simple calculation method

The dynamic short-circuit stresses in HV (high-voltage) substations with flexible conductors are determined by a large number of parameters. Tensile forces, stresses, and conductor displacements have been studied for short-circuit currents of 20-40 kA (RMS) in test arrangements representing strained conductors of typical 123 kV and 420 kV substations at a span length of 40 m. A simple calculation method based on the approach of IEC Publication 865 and DIN VDE 0103, but taking the short-circuit duration into account, has been developed, leading to reduced forces and displacements in the case of brief current flow