A penny saved is a penny earned!
Customer Challenge
Yercaud, a popular hill station in Tamil Nadu, India, is fed by only one source through Yercaud 22kV feeder. This feeder emanating from Hasthampatty 110/22 kV substation located at Salem in the foot hills of Yercaud runs for a total length of 140 kms. Owing to forest area in this route, frequent trips and breakdowns were experienced which led to severe criticism from public and media.
Several steps taken in the last 40 years has not yielded any desired results. TANGEDCO (Tamil Nadu Generation and Distribution Company), the then and current distribution company, decided to approach this problem with a new approach through Megawin Switchgear.
Usage of Auto Reclosers and Sectionalisers
Megawin switchgear supplied auto reclosers and sectionalisers, which were found performing well by sectionalising the faulty feeder pockets , without tripping the main feeder. This solution to TANGEDCO was offered at free of cost, to make a pilot study since it was a new concept to the DISCOM, in order to find an effective solution to the perennial problem.
Three sectionalisers were connected in crucial spur lines downstream of auto reclosers namely cauvery peak spur line, valavanthy spur line and yercaud town spur line. The contour of the single line layout of Yercaud 22kV feeder indicating the foot hills area, forest area and location of the sectionalisers over the forest area is furnished below.
The performance of the sectionalisers observed for a period of 8 months were exemplary and was a break through.
Valued Outcome
There was a considerable decrease in the number of trips in the main feeder after commissioning the above three sectionalisers. The number of trips dropped to 185 from 783 trips, observed over a period of five months.
Whenever a fault occurred in the sections of the spur lines only the connected sectionaliser had tripped, sectionalising the faulty spur line from the main line. Hence the customers whose lines were healthy remained uninterrupted.
With the faulty lines sectionalised, field engineers and staffs could identify the faulty pockets quickly and restore power without any undue delay. More importantly revenue loss suffered by TANGEDCO, due to unnecessary tripping of the healthy lines were now prevented and entire hill having a blackout due to a faulty spur line has now become a news of the past. TANGEDCO decided that by deploying the same scheme across all hill stations under its purview could lead to more revenue generation. The picture below shows the trips observed over a period of 5 months in comparison with the previous year’s performance.
