STATCOM application at VELCO Essex substation

On May 1st, 2001, the Vermont Electric Power Company, Inc., (VELCO) placed a +133/41 MVA, 115 kV STATCOM system on-line at the Essex Substation located near Burlington, VT, USA. The STATCOM, a flexible AC transmission system (FACTS) technology, was installed to provide dynamic voltage support and reactive compensation on the VELCO transmission system. The installation was part of a major transmission system project that also involved the reconfiguration of the Essex 115 kV Substation. This paper provides an overview of the VELCO Essex Substation STATCOM system project, and includes discussion on the power system requirements associated with the application, as well as a description of the STATCOM system design and layout.