Live Work Insulation Considerations on HVDC lines

Live work techniques can provide practical solutions for uninterrupted power flow maintenance on critical electrical infrastructures such as HVDC lines; however, there are potential risks including both electrical and mechanical aspects that need to be addressed. All transmission line components are designed to withstand maximum mechanical load under defined weather conditions; similarly, the insulation is selected to withstand normal operating overvoltage and meet defined reliability levels under various impulse or transient overvoltage such as switching, lightning, etc. Due to safety, live work is allowed under defined limited weather and electrical operating conditions only. Utilities are also mandated to comply with various relevant live work codes and standards based on national and local government regulations. Developing a HVDC line live work O&M plan is a comprehensive task and utilities often share their experience with each other. ATCO has contributed HVDC live work experience towards updating live work chapter in EPRI HVDC Reference Book. This paper provides practical support and reference to assess electrical insulation requirements on live work on HVDC lines.