Technical Presentations

Author(s): Jegadeesh Kumar
Type:Technical Presentation
Downloaded: 12
Date: 2022-09-01

Insulation coordination study of 220 kV transmission line for reliability improvement against lightning-induced overvoltages877

Abstract
This presentation shows a detailed insulation coordination verification using EMTP. It includes an accurate representation of transmission line components considering actual site data such as conducto... see morer arrangement, line length, line parameters, insulator details, tower structure and location, tower grounding resistance, and lightning data.

Tag(s): Insulation Coordination, Lightning Strike, LIOV, Line Surge Arresters, Back-Flashover

Author(s): Carlo Alberto Nucci & Fabio Tossani
Type:Technical Presentation
Date: 2021-09-07

Response of Overhead Lines to Direct Lightning Strikes: Assessment of the LEMP Effects852

Abstract
In the usual practice, the evaluation of the overvoltages due to direct lightning strikes to overhead power line conductors is focused on the representation of the effects of the lightning current inj... see moreection, whilst the effects of the coupling between the conductors and the lightning electromagnetic pulse (LEMP) is disregarded. Motivated by recent results obtained for the case of a medium voltage line configuration with a shield wire, this extends the analysis to assess the contribution of the LEMP on the lightning performance of an overhead distribution with and without periodically grounded wires and surge arresters. Moreover, the presentation deals with the LEMP effect on the occurrence probability of flashovers on different phases, which is an important information on the service continuity of networks with isolated or compensated neutral earthing. A validation of the results is obtained by comparing the overvoltages calculated by using EMTP, together with the LIOV library for the LEMP calculation, and those obtained by a three-dimensional finite difference time-domain approach.

Tag(s): lightning, pulse, LIOV, surge, arrester