IDGC of Centre is finalizing the preparation for maximum loads in the autumn-winter period (AWP) 2011\12. This year the focus was directed at preparing for the introduction of modern materials, advanced equipment and technology.
The analysis of unplanned outages of the last autumn-winter period showed that the main causes of supply limitations were damaged overhead power lines due to climatic conditions, icing, snow buildup on the wire (14% of all outages), the integrity of poles as a result of falling trees (29%) . Therefore, in order to increase the stability of power lines on 10 kV lines IDGC of Centre installs multi-sided metal poles.
The first two experimental 10 kV power lines on 28 metal multi-sided poles type SM80-6 and SM80-25 were constructed last year at IDGC of Centre — Tverenergo division. The length of the lines is more than 4 km, the height of poles is 13 m, the depth of burial is 5 m; SIW-3 (self-supporting insulated conductor) was used in the construction. The weight of the pole through constructive solutions — inside the pole is hollow — does not exceed 400 kg. This can greatly reduce the cost and timing of construction works. When lines are installed on steel multi-sided poles the share of the cost of construction works in total does not exceed 12%, while installing traditional concrete poles they represent more than 20%.
Steel multi-sided poles can withstand the maximum load build-up of snow and icing. During last year’s “ice” rains, when the number of outages in the area on other lines was several times higher than normal level, the pilot line with the use of multi-sided poles did not have any power failures. Steel pole is also much more resistant to corrosion.
The main advantage of a multi-sided steel pole, compared with reinforced concrete poles is its durability. Its life-cycle is not less than 25 years, moreover, inspection of the line will be required no more than once a year. The height of steel poles allows to increase spans on power lines without sacrificing the technical characteristics of the entire line. As a result, the cost of the line can be reduced by almost 2 times. Also, the multi-sided pole does not change in its structure when it has earth fault current going through the body of the pole.
“The analysis of the ‘pilot’ project in terms of economic efficiency and reliability has proved the need for multi-sided poles for the entire service area of IDGC of Center — noted Deputy General Director for Technical Issues — Chief Engineer of IDGC of Centre Sergey Shumakher.- The use of innovations, new technologies and modern equipment including steel multi-sided poles, in preparation for the AWP will significantly reduce the risk of emergencies and ensure sustainable reliable operation of electric grid facilities in the coming autumn and winter period”.
In the near future multi-sided steel poles will be installed in several branches of IDGC of Center and the project will cover all service areas where the company operates in 2012 (if the feasibility study is positive).