FDTD Simulations of Corona Effect on Lightning-Induced Voltages

Modified field‐to‐line coupling model for simulating the corona effect on the lightning induced voltages of multi‐conductor transmission lines over a lossy ground

“…will slow down the wave propagation velocity of the voltage source along the line due to the horizontal components of the electric field. This tendency agrees with the conclusion reported in [5] by Nucci et al,in [6] by Dragan et al,and in [16] by Thang et al, however, the increase ratio is similar to the prediction by Thang et al but less than those by Nucci et al because the corona model used in this paper is identical to Thang et al's theory.…”

“…In this method, the radial progression of corona steamers from overhead line was represented as the radial expansion of cylindrical conducting region, in which the conductivity was set to several tens of μS/m. By the comparison with measurements of Wagner's and Inoue's experiments, this method achieved a good accuracy and has been used for the overvoltage calculation under direct and indirect lightning stroke [15,16]. Obviously, this method has the advantage that it is more close to the actual physical realities.…”

Corona Effect Influence on the Lightning Performance of Overhead Distribution Lines

“…On the other side, when the CFO is higher, the influence of corona effect is meaningful. This result is in agreement with the conclusions of References [12,17], which have highlighted an increase of the lightning-induced voltages due to the corona effect. In particular, the enhancement can be caused by the decrease of the wave propagation velocity due to the increase of the line capacitance.…”

“…The implementation of corona discharge in the computation of lightning-induced voltages has been based on two different strategies: (i) The concept of dynamic capacitance has been proposed in Reference [12] that is, when the induced voltage overcomes a threshold, the corona discharge determines an increase of the per unit length capacitance involved in the Agrawal model [14]; consequently, the dynamic capacitance mimics the experimental q-v characteristic of the corona discharge [15]. (ii) In References [16,17] the 3D-FDTD code simulates the corona discharge giving different values to the conductivity of the cell where corona effect is located; the main difference with the previous approach is that here the q-v characteristic results as an output calculation from the numerical integrations, while in the previous one appears as an input of the problem.…”