The Pacific Intertie high voltage DC (HVDC) power line between the Pacific Northwest and the Sylmar neighborhood north of Los Angeles was commissioned in 1970. A 1360-km link, it was the first major HVDC power transmission line in the United States.

Path of the Pacific Intertie HVDC electric power transmission line.Path of the Pacific Intertie HVDC electric power transmission line.Although it was primarily designed to bring the advantages of relatively inexpensive hydropower from Oregon to California, it also allows power to flow in either direction. In the winter, power flows from Los Angeles to meet the increased demand in the Northwest for electric heating. In the summer, power flows to California to satisfy air-conditioning loads.

The Celilo converter station near the Columbia River in Oregon is the northern terminus of the line and the Sylmar converter station is at the southern end. ABB has been awarded a contract to modernize the Sylmar station.

ABB will install its MACH digital control and protection system, which was used in an upgrade at the Celilo station. Additional features will include AC and DC filters and shunt reactors, as well as measurement and auxiliary equipment.

The MACH system monitors, controls, and protects the hardware in the station. It also helps protect the transmission link from unexpected disruptions, such as lightning strikes. Incorporating fault registration and remote control functions, it is designed to run for decades.

ABB has been involved in more than 110 HVDC transmission projects representing a total installed capacity of more than 120,000 MW, about half of the global installed base.