Construction is underway at the Straits Substation in St. Ignace, Mich., to accommodate a device that will help operators better manage the flow of electricity between the Upper Peninsula and Lower Michigan. The Straits HVDC Flow-Control project by American Transmission Co. (ATC) is one of only a handful of such projects in the United States.
Despite significant upgrades to transmission infrastructure in the Upper Peninsula in recent years, operational challenges remain due to the delicate balance that exists between generation, load, market flows and transmission. ATC operators face challenges balancing the real-time reliability of the system and the need for outages to allow maintenance work to assure long-term performance.
The innovative, HVDC project will allow the flows between Upper and Lower Michigan to be controlled by MISO, maintaining appropriate thermal and voltage levels on the system. Approved by the MISO board of directors in June 2011, the project is eligible for cost-sharing as a baseline reliability project.
Project Description The station will use HVDC Light technology, designed by ABB, a leading international power and automation technology group. ABB will design and install the 200-megawatt station with two converters. In a back-to-back system, the two converters are connected directly to each other, without a DC transmission line, making it possible to fully control the power transfer through the connection.
The equipment will be housed in a tall control building with a footprint of about 280 ft by 110 ft.
Construction began in late spring 2012 with an in-service date in 2014. Cost of the project is estimated to be $130 million, which is a less-expensive and faster solution compared to the portfolio of transmission lines studied as alternatives.