Parametric analysis of parallel resonance on shunt compensated transmission lines

When planning a new transmission system, or the expansion of an existing one, a very detailed insulation co-ordination analysis must be performed to ensure that the installed equipment will be able to withstand the system voltages and currents arising under the most onerous operating conditions. This paper focuses on the evaluation of parallel resonant overvoltages in shunt compensated transmission lines. A parametric analysis of parallel resonance in a double-circuit line based on digital simulations is presented. The analysis covers both steady state conditions and temporary overvoltages (amplitude and duration) originated by switching operations. The effects of some key parameters such as line transpositions, line shunt conductance, soil resistivity and shunt reactor saturation are evaluated and discussed.