Design of an Underground, Hermetic, Pressurized, Isolated and Automated Medium Voltage Substation

This paper presents a new concept in underground medium voltage substations for an optimized operation performance and overall cost reduction. Due to its high-level embedded automation and communication systems, increased standards of reliability, availability and security are reached. Moreover, less expensive IP00 equipment can be used instead of higher IP-rated equipment, since the substation enclosure is hermetic and pressurized. Cost and time of construction works are reduced, as is the inconvenience to the population, especially when it comes to intense traffic areas. In addition, overall personnel labor is downsized, which reduces costs. In this context, the features and design guidelines of the proposed substation concept are presented, along with the methodology developed to address the thermal, structural and electric design issues.