Development of a Voltage-Dependent Line Model to Represent the Corona Effect in Electromagnetic Transient Program

Abstract

This paper describes a new method to represent single-phase overhead transmission lines (TL) under corona effect in electromagnetic transient simulation program. Based on Bergeron model and the scheme proposed by Dommel to represent transmission lines in Electromagnetic Transients Programs (EMT), a voltage-dependent line model (VDLM) was developed. This model can be represented through of an equivalent impedance network and easily combined with other components of the electric power system. To solve the nodal equations of the network a simple technique is proposed, which is suitable to calculate lightning overvoltages transients and avoids the necessity of iterative methods, increasing the efficiency of the algorithm. The proposed method was implemented in Matlab software, and the simulation's results were compared with field measurements to verify the accuracy of the model. Comparisons were also made with the traditional linear Corona Model. A good agreement could be observed between them.