1 Team BUSS Backup Storage Source

2 Team BUSS Backup Storage Source EHV Substation Second DC Storage Source Sponsor Idaho Power Company Team Members Rob Butzer Mitch Colburn Brian Vandenburg

3 Presentation Outline Project Background Customer Needs Reliability Analysis Alternatives Analysis

4 Background In EHV substations, battery banks are used to maintain operational control of the substation when ac power is lost The banks are able to control the relays and breakers, both used to help re-energize the system

5 Bank of up to 60 cells Each cell rated at about 2.1V Nominal Voltage of ~130V Present DC Battery Bank

6 Continuous load draws 5.5A for 8 hours to maintain station control Momentary load of A to be supplied after 8 hours for breaker control Minimum Voltage ~105V Present Battery Sizing

7 Present System One Line Diagram

8 1. Calculate reliability of present DC battery system 2. Seek alternatives for a backup dc storage supply and evaluate added reliability 3. Implement scaled prototype on a bench top system Customer Needs

*525,600 min/year = 35.7 min/year Present Fault Tree

10 Parallel Batteries

11 Parallel Battery Systems 4.624*10^-6*31,536,000 sec/year= sec/year

12 Evaluation Basis: 1. Reliability 2. Cost 3. Maintenance 4. Life Expectancy 5. Size Alternatives

13 Choice Matrix for Alternatives Alternative Initial CostMaintenance Predicted Reliability SizeLifetime Weighted Sum Lead Acid Batteries(flooded) Battery + Ucap Generator + Ucaps Generator Set NiCad Batteries Ultracapacitors Fuel Cells Flywheels Battery + Fuel Cells Compressed Air Dual Chargers10 Weight Scale:10=best1=worst*red denotes estimate

14 Viability of Alternatives Alternative Handles Momentary? Handles Continuous? Weighted Sum Viable Alternative Lead Acid Batteries(flooded)yes 7.5yes Battery + Ucapyes 6.8yes Generator + Ucapsyes 6.65yes Generator Setyes 6.3yes NiCad Batteriesyes 6.3yes Ultracapacitorsyesno4.75no Fuel Cellsnoyes4.35no Flywheelsnoyes4.25no Battery + Fuel Cellsyes 4.2yes Compressed Airnoyes3.9no Dual Chargersno 10no

15 Hybrid System: Battery & UCaps Initial Cost: ~$1000 plus battery resized? Battery used for continuous Ucaps used for momentary

16 Hybrid System: DC Generator & UCaps Initial Cost: ~$1500 Generator used for continuous Ucaps used for momentary

17 Bench Top System The goal of the bench top system is to show the effectiveness of a hybrid system and how it may be implemented in a EHV substation

18 Bench-Top Testing This is the one line diagram for the bench-top system that is currently being designed

19 Project Timeline

20 Discussion Conclusion