As a manufacturer of transmission towers and electrical hardware, we have been working for the last three years on developing a product which will make a big impact in the transmission line sector. The most important aspect of transmission line is to provide continuous and reliable power. But, these lines are subjected to several natural disasters like earthquake, flood, landslides and hurricanes. Power failure due to these scenarios make a severe financial damage to consumers, utilities and the power producing units. It is necessary that these transmission line utilities take precautionary actions to avoid and reduce these disruptions. Further, in order to address the increasing power demand, utilities are uprating their lines by reconductoring. However, this is problematic as the shutdown required for reconductoring cannot be provided as those lines are already invariably overloaded.
We planned on developing a solution which will help in reducing the outage time of transmission line. This led to the development of Emergency Restoration System Tower, an indigenous product of Supreme. It is a temporary structure designed to bypass the existing transmission towers of any voltage in any terrain. They will be used until the main line is reconductored or restored. The entire structure can then be disassembled and reused. Only a small outage will be required to bypass the main line to ERS.
The unique feature of Supreme ERS is that they are made of High Strength Steel. The fully standardized fabrication process of High Strength Steel has made it an economical, functionally reliable and structurally stable option. The savings due to reduced outage time far outweighs the cost of such Emergency Restoration System which is now substantially reduced with the use of steel. The entire design is made in such a way that the whole structure can be erected in few hours. Sections are made modular in order to ease transportation as the site may be very remote to carry the structure. There is no need for any civil foundation. Erection is made ease with the usage of Gin Pole which obviates the need of heavy machineries. Use of composite insulated cross arm will reduce the crossarm load on the structure and also the clearance required for insulator swing.
The tower is entirely supported using guy wires. Hence it is essential that all the guy wires are properly anchored to the soil. In a conference organized by CBIP, TATA Power published a work where they mentioned that they were unable to use a temporary structure for restoring the line because of the marshy soil condition which will not be able to take the mechanical load of the structure. Our team took this as a challenge and developed different kind of anchors that would support the structure in all soil conditions.
Our first project was to bypass an existing 132-kV transmission line in order to facilitate the construction of a nearby flyover. A line length of 1800 circuit metres, which passes through a residential and heavily crowded commercial area in Sector 2 of Vaishali, was at standstill and lying abandoned after completion of foundation works since January 2017 and waited for a shutdown for a minimum of 10 days, for completion of erection of 2 Nos. Multi-circuit Towers and stringing to follow.
There were several 11kV and 33kV along the line which was the major challenge for us at the time of stringing. The line was serving a large number of people and hence getting shutdown for bypassing the line was very difficult. UPPTCL provided the required shutdown, five days after the structure erection. After complete installation, there was a severe hailstorm but the tower withstood the same without any damage to it. The bypass line was in charged state for a month serving the utility’s customers who didn’t have to undergo suspension of service. This new experiment played a significant role in promotion of line uprating by re-conductoring of old lines without necessitating the need for new ROW. The key thing to be noted is that this is the first ever bypass arrangement made by an Indian Manufacturer on a High Voltage Transmission Line.