Energy / Renewables and Environmental

Essex Substation in Vermont, USA

The Essex Substation in Vermont, USA was installed to compensate for heavy increases in summertime electric usage, which had rendered the existing system increasingly vulnerable to failure in the event of problems elsewhere in the VELCO transmission system. The six STATCOM converters installed by Mitsubishi Electric Power Products Inc. produce large amounts of heat when operating, which is greater than the converters can withstand. Two cooling systems designed and programmed by Fairfield Control Systems circulate a water/glycol mixture through the STATCOM converters to thirty cooling fans where the heat is dissipated. The fans operate only when required to reduce power usage although the coolant is constantly circulated, as the converters are unable to withstand more than a three second loss of coolant when on load. The converters, when installed, were valued at a price in excess of $1,000,000.