Modelling of Metal Oxide Surge Arresters in Simulation Software DYNAST

This paper describes the possibilities for mathematical modelling of gap-less surge arresters in simulation software DYNAST. This tool does not belong to standard modelling softwares in the field of electric power engineering. However, it may provide some key advantages when compared to more frequently used softwares such as EMTP-ATP and MATLAB-Simulink. Description of the metal oxide varistor modelling at temporary and switching overvoltages, fast-front states, and lightning strokes is presented. More information about the defined internal structure of surge arrester models and ways for implementing respective V-I characteristics are provided. To verify the correct behaviour of the models, both slow and fast overvoltage scenarios are simulated and evaluated.