Lightning discharge effects on overhead lines metal constructions | Zibens izlādes iedarbība uz gaisvadu līniju metālkonstrukcijām

لاتفيا. Šajā rakstā ir sniegts apraksts augstsprieguma gaisvadu līnijas (GVL) zibens izturības datormodelēšanas paņēmienam, izmantojot EMTP datorprogrammas ATP Draw grafisko apakšbloku. Datormodeļa konstruēšanai par pamatu ir izvelēti U330-2 un P330-2 unificēto 330 kV līniju metāla balstu gabarītizmēri un līniju ģeometriskie parametri. Aprēķinu rezultāti rāda, ka gan zibens izlādes vieta GVL, gan līnijas konstruktīvo parametru izvēle ietekmē modelēšanas procesa gaitu un rezultātus, kā arī var redzēt, ka modeļa analoģisko uzbūvi var pielietot arī citām režģveida metālkonstrukcijām.

إنجليزي. The intention of this paper is to present lightning induced atmospheric overvoltage waves propagation in overhead high voltage transmission lines metal constructive elements. The paper presents a calculation results of selected high voltage lines P 330-2 and U330-2 metal towers structure effect and lightning discharge point effect on transmission line on atmospheric overvoltages propagation, simulated on ATP Draw graphical interface of EMTP program. Computer simulation results shows, that the constructive parameters of high voltage line metal construction elements (transmission tower, gantries, ground wire etc.), together with variation of lightning strike point (on ground wire middle point or directly on metal tower) may detailed simulation process of lightning discharge and affected simulation results. Quantitatively, for operating in Latvia high voltage transmission lines, the difference between tower different metal parts can be up to 160 kV for P 330-2 towers, when lightning strike registered on ground wire middle point and 180 kV, when lightning strike registered on metal tower construction. In case of U 330-2 towers, these values are 130 kV, when lightning strike registered on ground wire middle point and 150 kV, when lightning strike registered on metal tower construction. The critical value of lightning current of 35 kA (on Heidler source), has a significant effect on the simulation results of the degree of power lines protection from lightning overvoltages. The detailed simulation of transmission line metal construction elements and lightning discharge point variation enables to understand a reaction of power system to lightning overvoltage wave propagation. The simulation model consists of the information about each constructive element of the transmission power line.