BACKGROUND
The Mesquite Creek Wind Farm is a massive 25,000 acre infrastructure project (roughly the size of Paris, France) near the rural West Texas town of Lamesa, halfway between Lubbock and Midland.
Mesquite Creek's proximity to its interconnection point -- the Long Draw substation, part of the state's $7 billion recent transmission upgrades designed specifically to carry renewable energy generated in West Texas to load centers in the east -- and unique topography along the caprock escarpment made it a particularly attractive site for a wind farm. (REFERENCE)
Construction of the 200 MegaWatt wind farm began in 2014 with about 10 turbines going up each week. Each of the 118 turbines is capable of producing 1.7 MW of power for an annual output of more than 800,000 megawatt-hours, or the equivalent of powering 61,000 U.S. households.
PROBLEM
On the evening of Friday, September 23, 2016, a 34.5kV transformer failure was discovered at the Mesquite Creek Substation.
The transformer switch failed to fully make contact, which lead to catastrophic arcing and ultimately causing the switch and adjoining expansion fitting to melt and fail completely.
The switch failure directly led to 59 of the 118 Turbines – 100.3 MW of power per day - to go down immediately. A certified Aluminum Welder and alternate connectors would not be available for at least 2 weeks. With potential losses to the utility estimated at $180,000/day ($2,700,000 for a full two week outage), every hour was critical.
SOLUTION
The utility was familiar with DMC Power and knew we could respond quickly with the restoration. At about 10:30 pm that Friday evening (9/23/16) our local Territory Manager received the call. Pictures of the damaged expansion joint and switch assembly were sent and we went to work figuring out a solution.
By 8am the following morning we had confirmed all bus sizes, parts required (PLK2600 & PLK1001) and DMC Power Swage Tools to install. The Purchase Order was received and we immediately started manufacturing the parts in our Los Angeles facility that Saturday morning.
INSTALLATION
On Wednesday morning (9/28/16) our Territory Manager and Area General Manager arrived onsite at 7am with DMC Power Swage Tooling in hand, ready to conduct user training.
Shortly thereafter the connectors were delivered and the work began:
- Failed switch was removed
- Damaged welded expansion fitting and adjoining bus were cut out
- The new switch was installed
- DMC Power Expansion and Long Splice connectors were installed. There was no extra bus available so we manufactured a long splice (PLK1001) to compensate for the extra bus length being cut out.
- DMC Power was on site for technical support until the early evening, when the Switch was finally adjusted and the entire substation was fully restored.
RESULTS
The customer performed resistance checks across the installed expansion joints with the following results:
- Phase A: 623uohms (DMC Power)
- Phase B: 873uohms (Welded)
- Phase C: 861uohms (Welded)
The resistance difference of the DMC Power connector was 200uohms (28%) less than their welded counterparts were.
From the fast responses and lead times…
- Immediate Friday evening response
- In person meeting with the utility within 2 business days
- Swage Tooling in 2 Business Days
- Swage connectors in 3 Business Days
… to the entire Swage System technology, superior resistance qualities, incredibly fast installation and unheard level of onsite customer support, the overall customer response was extremely positive.
“Why would anyone ever weld again if they could use this”
“Thank you for spending the entire day on site to see this through to completion”
“I can’t believe three of you showed up to support this”
DMC Power was happy to help getting this important project back online and we look forward to assisting the customer on future projects.