The Bonneville Power Administrator put the modernized Celilo Converter Station into service Thursday.  Construction on the 370 million dollar project began in the fall of 2014, and the station had been out of service since October for final installation and testing.  Modernization of the converter station, including six massive new transformers, each weighing more than a Boeing 747 airliner, anchors a $498,000,000 package of BPA-funded grid upgrades to the northern leg of the Pacific Direct Current Intertie, which connects the Northwest with Los Angeles.  When the final phase of the overall project is completed this fall, the BPA transmission-line upgrades will raise the capacity of the intertie from 3,100 to 3,220 megawatts.  BPA, which funded the improvements, is also in the process of upgrading the 265-mile portion of intertie that it owns from the Columbia River to the Nevada-Oregon border.