Stations and power plants use dc supply systems to sustain station control functions during periods of loss of the ac power system. Many EHV stations have a single battery and charger. The eastern US blackout of 2003 and other system events have revived the interest in protection system redundancy. The focus is on implementing systems with no single points of failure. The battery and charger can be a significant single point of failure that is expensive to mitigate.
This project is to determine the reliability of the present dc storage system and evaluate options available to mitigate the dc supply (local service transformer, dc charger and battery) single point of failure within the protection system. The reliability and economics of alternative dc storage options will be considered and a recommendation will be made to Idaho Power based primarily on cost and reliability of these alternatives storage systems.