Modularization of High Voltage Gas Insulated Substations

Many existing petrochemical facilities are replacing outmoded high voltage (HV) air insulated switchyards (AISs) with new gas insulated switchgear (GIS) substations. Modularization or prefabrication has strategic advantages over site-built substations. While medium voltage (MV) and low voltage (LV) substations have been modularized for many years, the HV GIS substation modularization has not caught up with the construction industry. The modularized HV GIS substations are significantly different compared to other electrical MV or LV substations. This article addresses the modern philosophy and approach to modularization and how the end-user can benefit, in terms of design flexibility, cost-effectiveness, reduced lead times, premium quality, and accelerated site execution in a new or an operating facility. It describes the technological developments, design concepts, quality assurance, and environmental impact in delivering complete solutions based on site conditions.