How do you perform under pressure? Unless you’re tested, you’ll never know for sure.
In the electricity industry, the Bonneville Power Administration plays in the big leagues. And in the bulk power marketing game, there’s no halftime, no TV timeouts, no rainouts, no off days. BPA’s transmission system has to play at the highest level night and day, and through windstorms, snow, ice, heat waves, plagues of grasshoppers – come what may, the lights stay on.
Early this fiscal year, BPA needed to learn whether its $370 million prime-time player was ready to perform the feats it was designed for. In the high-voltage direct-current arena, that means herding electrons, straightening and rebraiding the huge waves of electricity moving along the West Coast. Much of that volume is the carbon-free power generated by the 31 federal dams of the Columbia River system.
Not far from the river, in The Dalles, Oregon, a highly technical construction project to refurbish the Celilo Converter Station wrapped up last fall. That’s when a crack team of engineers and operators began a series of more than 100 challenges calculated to push the new, interdependent components through their paces to test their strength, responsiveness and reliability.
BPA, which pioneered the art of long-distance high-voltage direct-current transmission in the 1960s, has an illustrious history of transmission engineering and testing prowess.
With safety as the top priority, BPA’s line crews set up electrical faults for tests such as this one near the Oregon-Nevada border on the Pacific Direct Current Intertie, which runs between Celilo and Southern California.
“It would be a fair statement to say that Bonneville is well known in the national power community for being a technology leader,” says Alan Courts, retired BPA vice president. Courts – described by project manager Karl Mitsch as “a top-shelf power system engineer who is also fluent in ‘executive’ ” – wrote the business case for the massive upgrade to the Celilo Converter Station.
The largest turn-key project in the agency’s 79-year history, the Celilo upgrade represents the latest example of BPA’s contributions to grid modernization. For transmission customers and the West Coast, there was a lot on the line.
“If you’d invested $370 million, you’d want to be sure everything worked correctly too,” said Jeff Hildreth, senior electrical engineer at BPA’s Carey High Voltage Lab.
That’s why BPA test engineer Steve Lowder was poised on the edge of his chair, phone to ear, in the brand-new digital control room at the converter station.
On this January morning, the air was charged with anticipation. The Pacific Direct Current Intertie, which runs between Celilo and Southern California, is the largest high-voltage DC line in the United States. Everyone in the crowded room knew that a transmission system capable of powering three cities the size of Seattle was going to receive a jolt.
“I get a huge adrenaline rush about 15 minutes before we do it because I know what’s coming,” said Lowder, a veteran of hundreds of similar tests since joining BPA in the 1980s. “It’s like playing in the Super Bowl – everyone’s watching what you’re doing and everyone knows you have to do it right.”
Hildreth added, “Like a NASA space launch, it comes down to those last minutes or seconds, but there’s been months or years of planning and preparation that went into that one little moment. Steve Lowder does a heroic job of organizing a lot of moving parts.”
Among those moving parts, a crew of linemen 846 miles away at the Los Angeles Department of Water and Power was preparing a carefully choreographed insult to the system. Using a rope carrying a fuse wire on the end, the foreman reported by phone that they were setting up a pendular fault. In laymen’s terms, they were about to intentionally short out some very big wires – carrying 500 kilovolts – under tightly controlled conditions to ensure safety. BPA line crews performed similar tests near Celilo as well as 265 miles south, where the DC intertie crosses the Nevada-Oregon border.
Back at Celilo, project manager Karl Mitsch was among those intently watching the test unfold. Before joining BPA, Mitsch was a project engineer at General Electric, managing major equipment installations at utilities around the world. He said Bonneville’s testing protocols and standards are unique.
“Staged system testing is very rarely done, where you go out and induce a fault,” Mitsch said. “It’s risky to put faults on the system; we’re going to short that wire out and it’s going to go, ‘Kaboom!’ But staged- fault testing is invaluable because it verifies that everything is working correctly. Other utilities didn’t do that. Bonneville’s a pioneer in staged-fault testing – we’re the only ones who do it this way.”
The goal of the exercise was to see how Celilo would handle the electrical interruption and subsequent surge on the high-voltage lines. Would its tens of millions of dollars of new gear – from the tiniest computer chip to new transformers that outweigh a Boeing 747 – show the instantaneous agility to absorb the shock and return to regular service?
“All that protection and control should happen in less than a half second,” Lowder explained.
With the help of Celilo Chief Operator Dave Potter, his crew and their counterparts at the Los Angeles-area converter station anchoring the southern end of the intertie, Lowder began the incantation of the testing ritual: “One minute --”…. “30 seconds -- ” …. “20 seconds --”….
“Ten. Nine. Eight. Seven. Six. Five. Four. Three. Two. One… Go!”
As many in the room held their breath, the foreman in L.A. triggered the fault. The staff assembled at Celilo watched the home-theater-sized control screen as the system registered the shock, rose to the occasion and then settled back into its ordinary pattern of operations.
One glitch was minor: A bit of misdirection from a new tool called a fault locator, designed to pinpoint the location of any problems along the 846 miles of the intertie. The technology can save line crews hours of patrolling in rugged country to find the exact site of a transmission disruption. Except during the test, the locator reported a phantom fault… about 15 miles off the end of the transmission system. “That’s somewhere down Doheny Boulevard,” one person joked.
This was only one in a very long sequence of testing for Celilo. BPA teams perform months of complex computer modeling and system planning leading up to each event.
“Want to see a test plan? It’s a book,” Potter said as the program was in full swing last winter. “We’re doing hundreds – hundreds – of these.”
The Celilo project wound up passing the arduous battery of tests with flying colors, reflecting the strong engineering partnership between BPA and ABB dating back to the 1960s, when Celilo was designed and constructed.
“It really surprised me how well all of it went,” Mitsch said of the testing. “The amount of punch-list items (fixes) we had to address at commissioning was quite low. Most of them were not really showstoppers, they were more like refinements. There were routine, fairly benign, yet important things that we discovered and that were corrected.”