Premature Failure and Remedial Measure for Prototype Testing of UHV Transmission Line Towers: An Overview

The need for adopting bulk power transmission system with all possible ways to make support structures economical and also to reduce the Right of Way (ROW) requirements has arisen in view of accelerated growth of electrical network. This bulk power transmission has become compelling due to separation of power sources to the areas requiring the power located at longer ranges, namely interstate and inter-regional. In this direction, 400 kV D/C and M/C system with a quadruple conductor configuration, 800 kV/1200 kV AC system and ±500 kV/800 kV HVDC systems are now adopted in India. Recently, CPRI has successfully tested the self supporting type of 765 kV and 800 kV AC and HVDC towers for POWERGRID. The prototype testing and the premature failure of these towers in particular and some of special towers in general are described in this paper.