COMPACT EHU TRANSMISSION LINES WITH INSULATING INTERPHASE CONNECTIONS  Fulltext 

[ Krylov ] - UNTIE, Russia
[ Timashova ] - UNTIE, Russia

خلاصه مقاله:

For the first compact EHV overhead lines of increased capacity (500kV line which is under project now and 300kV line is under construction [1]) a V-type insulator strings for bundle conductor suspension are used. Minimal adopted distance between phase conductors correspond to the norms used in the USSR for designing of EHV overhead lines of traditional design, conductors of which, are suspended on vertical suspension insulators strings (table 1).
For further increase of EHV lines transmitting capacity as compared with above mentionedtechnical solutions it is required to achieve even shorter distances between line phases [1]. Data given in table 1 show that distance between phases of 440kV line theoretically can be lessened up to 3.1 - 3.5m (compare wit.. 5.5m distance in a project for the 330kV overhead line between Pskov thermal power plant and Novosokolniki) and up to 4.2 - 4.5m for a 500kV line (compare with 8m in a project for the first compact 500kV line).
But, it should be taken into consideration the fact that minimal interphase distance can be secured only in case of fixed position of conductors in a span which completely exclude any, mutual phase conductors movements. Such fixation of flexible bundle conductors systems in a span can be created only by application of insulating tie-fixtures (see fig. 1) [2] Their structures can be developed on the basis of polymer pin and also suspension glass or porcelain insulators. Insulating suspension of conductors with lessened interphase distance, shown on fig. 1, is fixed for limitation of their movements under wind loads due to creation of a tense flexible shroudtype system. Phase conductors are freely suspended on tangent towers on suspension insulator strings and after assembling they are additionally tightened by two insulating ties in a span. Additional fixation of phase conductors in a span serves for load redistribution on all suspension elements of conductor-insulator string and interphase insulating spacers under the influences of all types on conductors of one phase.