Design of Towers for EHV/UHV Transmission Lines for Specific Site Requirements Pundir Karanvir Singh, Sinha Nitesh Kumar, Vyas A.K., Taneja S.C., Anand Anish, Singh R.N. Power Grid Corporation of India Limited, Gurugram Online published on 6 February, 2020. Abstract A number of transmission lines have been constructed across India from north to south and east to west to evacuate power from different parts of the country in the last few years. Transmission line system with voltages ranging from 66 kV to 1200 kV have been designed and constructed in the last few years. There have been a number of occasions where high voltage line such as 765 kV D/C line has to cross another high voltage line and to make crossing arrangements availability of space to erect tower sometimes is not adequate. This situation possesses a big challenge and demands to design and develop a special kind of tower with a narrower base width and a taller height required for crossing along with the special design considerations. These kind of high voltage towers are then easily accommodated in the narrow space and are tall enough to cross the intercepting line. These transmission lines also pass through some major rivers which are having width ranging from 1–1.5 km. India is blessed with huge network of rivers, mainly carrying water from mountains and is mostly perennial in nature. Most of the times the water flows throughout the year in the rivers and it becomes difficult to spot any tower with deep foundation in the mid-stream. Further, as most of the rivers are navigable, therefore to maintain adequate electrical clearances and to account for long span and huge sag, the height of tower goes up to 170–180 m. Accordingly special considerations are then followed for the design of such long slender towers. Furthermore, there have been numerous occasions when lines are to be terminated at substations with very limited available corridor/severe space crunch as already many existing lines are terminating at the substation. These lines occupy most of the corridor and there is hardly any space left to accommodate any new line. In one of the case, a line was required to be terminated in the substation with no any corridor as available space between the two existing line was already occupied by another tower which was to be used to cross the existing lines at the same place. Due to the severe space crunch near substation, a special kind of tower has to be designed. The paper covers in detail, salient design aspects and other special design features of narrow base towers 765 kV D/C DDN+55 & 800 kV DDN+60, 765 KV D/C river crossing towers and special Power line crossing tower designed for site specific requirement. Top Keywords Narrow Base, River Crossing, Power line crossing. Top |