Study of influence of corona effect on 110 kV overhead line, lightning protection cable on energy characteristics of linear surge arresters during lightning overvoltages

Abstract

The corona effect has a significant impact on calculations of lightning protection of the high-voltage overhead transmission line. The corona effect in the calculation of the transient process during a lightning overvoltages is often neglected due to the complexity of modeling the corona effect. The issue of the corona effect influence on the operation of non-linear surge suppressors installed on overhead lines hasn’t been sufficiently studied. The aim of the research is to evaluate the energy characteristics of linear surge arresters considering the corona effect on the overhead line. Simulation of the transient process on the overhead line during lightning overvoltages is carried out in the EMTP-ATP software. There is no corona model among the basic models in EMTP-ATP software. Thus, the corona model on overhead line wires using dynamic capacitances is under consideration. A model of corona on overhead line wires in EMTP-ATP is developed. Calculations of energy characteristics of linear surge arresters on an overhead line model considering the corona and without corona effect are carried out. The comparison of the obtained energy characteristics is carried out. The corona has a significant effect on the energy absorbed by the linear surge arresters during lightning strikes to the ground-wire if the front time of the lightning current impulse has a value near 1 s. When lightning strikes to the phase wire, the energy absorbed by the linear surge arresters is so great that the influence of the corona effect is insignificant. The corona model used in calculations in EMTP-ATP software has several limitations. Therefore, in future research it’s advisable to improve the model and simplify it, when calculating lightning protection of overhead lines.