Minimum Voltage-Current Characteristic for Calculating Surge Arrester Energy Dissipation in Temporary Overvoltage Conditions

A method is described for estimating required energy capability of surge arresters with respect to temporary overvoltages (TOVs). The method makes use of surge arrester catalogue data on thermal energy rating and TOV capability for estimating minimum voltage-current characteristics suitable for energy calculations by electromagnetic transient simulation tools. The need to recalculate composite TOV events for comparison with TOV capability curves is thereby avoided; this makes the method especially useful in conditions of resonant TOVs comprising harmonics, e.g., from energization of transformers in transmission networks with a large share of underground cables.