Innovative Compact Line Design – Reducing Clearances by Integrating EGLAs on HV Transmission Lines by Bastian Robben
Growing demand for power has resulted in need for increased transmission capacity and power quality. These days, developed countries encounter growing difficulties building new transmission lines due to public opposition and environmental considerations and it becomes necessary instead to ‘uprate’ existing power systems. Moreover, even if public approvals are obtained, line designers are often requested to create new concepts and structures to reduce footprint and visual impact. Line compaction and uprating involve the need to review conventional ratings and standard designs used for decades. Fortunately, the latest developments in composite insulators and surge arresters make compact line design a realistic alternative to traditional designs. For example, taking surge arrester functionality into consideration, structure clearances and insulator arcing distances can be reduced and power availabilities improved simultaneously. Conventional ratings such as lightning and switching impulse withstand values of insulator assemblies can also be coordinated with application of transmission line arresters to achieve advanced insulation coordination. This presentation describes principles of transmission line surge arresters and reviews opportunities to optimize transmission line capacity and power quality. It also explains the technical challenges that have to be considered when implementing compact power system solutions.