Transcript Slide 1

Little Falls Powerhouse Modernization
Presented by Brian Vandenburg
Avista Utilities, Spokane, WA
Welcome to Little Falls
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Act of Congress in 1905
Commissioned in 1912
Four units at 9MW each
600ft Spillway
Why Little Falls?
September 2010
Damaged breaker,
commutator and
generator winding
January 2010
Damaged breaker
and commutator
July 2006
Damaged breaker
and commutator
Little Falls Scoping
Vertical vs Horizontal
• Payback
• Logistics
• Foundation Unknowns
Engineering Troubles…
Turnkey Design
In House Design
Little Falls Schedule
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Exciter and Breaker Upgrade
Crane Upgrade
New Warehouse
Station Service Infrastructure Upgrade
Unit 3 Outage
Station Service Auxiliary Systems
Unit 1 Outage
Headgate Upgrade
Unit 4 Outage
Spillgate System Upgrade
Unit 2 Outage
Completed
Completed
Completed
In Construction
July 2014 - Feb 2015
Spring 2015
July 2015 - Feb 2016
July 2015 - Oct 2015
July 2016 - Feb 2017
???
July 2017 - Feb 2018
Medium Voltage Breakers
4kV Breaker Upgrade
Uprated the generator breakers and buswork
Excitation System
Exciter System Upgrade
Amplidyne & Rotational Exciters replaced with Static
Excitation System
Crane Upgrade
Replaced motors for all four motions. New cab and radio controls.
Dealing with a small powerhouse
Loading bay inside the plant is only 20ft wide, making logistics challenging
Long Lake
Warehouse
The Long Lake Warehouse
was built 8 miles from Little
Falls to be shared between
the two plants
Station Service Upgrade
New transformers, low voltage
switchgear and motor control centers are
being installed. Designed for future
expansion.
How to Get Funding
Original Little Falls generator half and turbine being delivered to site
Generator Replacement
Generator frame design to ‘LOOK’ like the
old frame as much as possible
Unit Upgrades: A Quick Look
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Replacing 9MVA generators with 12MVA generators
Replacing turbines on units 1, 3 & 4.
New PLC-based governor and HPU system on all four units
Protection and Controls Upgrade
New generator cables
Rebabbit generator and turbine bearings
Reinsulate field poles to class F
Flow monitoring
Aux System overhaul: Bearing Oil system, Brakes, Vacuum
BKR, Wicket gate resleeving and painting
Little Falls HED, circa 1915