Backflashover simulation of HV transmission lines with enhanced counterpoise groundings

Generalized pi-circuit tower grounding model for direct lightning response simulation

“…According to [22], the model "strictly applies to earth electrodes with small extensions (a maximum effective diameter of 30 m is estimated)". In high g soil, where relatively low R o values require spatially extended and/or complex grounding arrangements, the model is no longer applicable [16].…”

“…Although less accurate than field-based ones, circuit models are less computationally expensive and easier to implement, especially with regard to soil ionization. This makes circuit-based models particularly useful when the grounding system model is embedded in complex power system simulations such as the evaluation of OHLs lightning performance [15,16] (some authors also developed interesting 'hybrid' models using both approaches, 'circuit' and 'field' [17,18]). Simplified circuit models can be used for transient studies when grounding electrodes are relatively small (maximum length under 30 m).…”

Monte Carlo method for estimating backflashover rates on high voltage transmission lines

“…NG · f (I) for I ≤ I m LN g (2D g + S g ) NG · f (I) for I ≥ I m (16) in which f(I) stands for the PDF of the general (negative downward) lightning current amplitudes. It can be shown that this new PDF function g(I) depicts also a log-normal distribution.…”

“…30 m), frequency-dependent tower grounding impedance model is needed. Its implementation can be somewhat complicated [16]. On the other hand, within some 30 m of the tower base (i.e.…”

“…Further important simulation details, concerning the backflashover analysis on HV transmission lines, can be found in Refs. [12][13][14][15][16][17].…”