Blackwater

The Blackwater back-to-back station near Clovis, New Mexico interconnects and enables power exchanges between two asynchronous power grids, the Western North American Interconnection and the Eastern North American Interconnection.

The station is owned by the Public Service Company of New Mexico (PNM) It was onstructed by BBC Brown, Boveri Inc. in 1985, and can transfer power up to 200 MW. The used voltage is 57 kV.

Back-to-back HVDC installations are most typically used in applications where two asynchronous power systems must be interconnected. Unlike point-to-point HVDC transmissions, in a back-to-back installation both converter stations - the rectifier (converting AC power to DC) and inverter (converting DC power to AC) - are housed in the same location, with DC buses connected through a smoothing reactor.

In 2007, Hitachi Energy was awarded a contract to upgrade the Blackwater station. The valve cooling system was exchanged and the control and protection system was replaced by a fully digital MACH Hitachi Energy control system.

Hitachi Energy has the widest experience of control system upgrades in the HVDC industry. Two other upgrades in the U.S. – the CU and Square Butte HVDC links between North Dakota and Minnesota have set industry benchmarks for rapid project completion and minimal transmission disruption. Hitachi Energy completed a similar upgrade of valve cooling and control systems for the Intermountain Power Project in Utah.