1. Grant County PUD Plant Upgrades at Wanapum and Priest Rapids Dams
Kevin Marshall, PE GC PUD Hydro Engineering Manager NWHA Conference February 18, 2014

2. Ongoing Upgrades for Wanapum Dam
Turbine Replacement (Note: GCPUD took advantage of CREB bonds and a DOE design/development grant) Work is complete.
Generator replacements
New exciters
Digital Governors
Transformers

3. Reasons for Turbine Upgrades
Original turbine runners had reached the end of their useful life
Blade crack repairs
Trunnion seal issues
Operating linkage failures
Cavitation repair costs - $75,000/unit/year ( average costs)
Performance improvements
Improved fish passage survival

4. Wanapum Turbine Upgrades
Design Features
Semi to fully spherical
Larger diameter: 20 inch increase
Deeper setting : feet deeper
Performance Improvements
Increased capacity: 120khp to 150khp
Efficiency improvement: 3% average weighted efficiency
Cavitation repair costs: $0

5. Reasons for Generator Upgrades
Replace components at the end of their life.
Capture increased output of new turbines

6. Wanapum Generator Upgrades
New Parts
Complete Rotor
Complete Stator
Generator Shaft
Ventilation System
Excitation System
Air-Gap Monitoring
Rotor spider arrives in 3 sections, stator frame in 4

7. Wanapum Governor/Unit Control Upgrades
What
Mechanical governors replaced with digital
Dynamic exciters replaced with static exciter and digital controllers
Why
Spare parts no longer available
Serviceman knowledge not transferred with retirements
Improved control/efficiency
Improved protection
More info/better trouble shooting
Lower costs to maintain

8. Existing Wanapum Mechanical Governors

9. New Wanapum Digital Governors

10. Current Wanapum Status
10th turbine, 4th generator, 4th exciter, and 3rd governor complete and put into service October 2013
5th generator, 5th exciter, and 4th governor under construction
10th generator and exciter to be completed in 2019
New turbines have a averaged, weighted efficiency gain of 3%
As tested new generators have an increased efficiency from 98.0% to 98.5%
2 of 5 transformers replaced, 3rd transformer in process

11. Priest Rapids Dam Upgrades

12. Planned Upgrades for Priest Rapids Dam
Turbine Replacement or life extension
Generator rewinds
New exciters
Digital Governors
Transformers already replaced

13. Reason for Upgrades Efficiency improvement Life Extension
Aging equipment
First unit in service in 1959
Generators
Rotor pole problems including pole to pole connection failures (as pictured)
Stator Winding age (oldest unit = currently 27 years old)
Exciters are obsolete
Turbines starting to exhibit problems
Increased cycling of governor oil pumps
Wicket gate operating ring wear

14. Turbine Upgrade Process
Goals
Utilize lessons learned from Wanapum project
Obtain as many qualified bids as possible
Competitive turbine hydraulic model testing
Integrate biological considerations into design effort

15. Turbine Upgrade Process
Step 1: Hydraulic design contract
Professional Services Agreement
Prequalification process – three contractors prequalified
All design solutions finalized by contractors ahead of bidding
All design solutions verified by independent hydraulic laboratory
Step 2: Manufacture and supply contract
Bidders must participate in hydraulic design contract to bid
Performance guarantees verified prior to bidding

16. Status of Priest Rapids Upgrades
Turbines
Model testing was completed last week in Lausanne, Switzerland for the 3 qualified vendors
Bids are due March 5th
Contract award this summer (if economics are favorable)
Generators: Pre-qualification of Vendors in process
Controls: Governor specifications are in process
Field work for upgrades is scheduled for 8/1/2016

17. Priest Rapids and Wanapum Upgrades
QUESTIONS