Reducing air clearance requirements for voltage uprating of overhead line by use of line surge arresters

While uprating an overhead line to a higher voltage level, it is often difficult to achieve the required clearance level for the uprated structure. Use of Transmission Line Arresters (TLAs) is an effective technique in controlling overvoltages and thereby, achieving the required clearance margin. In this paper, suitability of this technique in reducing the clearance margin is discussed. A case study on uprating an existing 275 kV overhead line to 400 kV is investigated here.