Mine Ensures System Stability With Power Management Solution

Islanded power systems prioritize stability and resiliency over tripping selectivity to avoid widespread blackouts and ensure power can be fully restored after breakers trip. SEL powerMAX Power Management and Control System solutions offer features like load shedding, generation control, and load management to mitigate blackouts and other electric system events.

Challenge

After experiencing three separate blackout incidents within one year, Red Dog Mine decided to improve their blackout mitigation as part of a larger electrical system improvement. Located in a remote area of Northwest Alaska, the mine has no utility connection and is a fully islanded facility.

Their existing solid-state protection equipment provided minimal data after a trip—only targets with no time tagging—making it impossible to find a definitive root cause after an event.

An improved protection system was needed to clear faults with as much of the system surviving as possible and to provide the information needed to assist in quick restoration.

Solution

Engineers designed a powerMAX generation control and load-shedding system to maintain voltage and frequency stability. They also designed a reliable and secure protection system and SCADA control system for implementing a bus preservation scheme that allowed systems to operate as separate islands.

The powerMAX system interfaced directly with interconnected protective relays to control generators and perform load shedding.

Electromagnetic power system transient simulations were used to demonstrate how the system would operate with a generation control system, load-shedding system, and protective-relaying bus preservation scheme. The system was tested for faults at different locations to ensure that it would remain stable and operational after a disturbance was cleared.

Results

Red Dog Mine typically uses six generators to carry their load, up to 30 MW. When the mine experienced an overcurrent event, the powerMAX system properly isolated and shut down one generator, temporarily reducing production loads.

The mine saw a 2 percent reduction in throughput until full power was restored, and it remained operational with full visibility of the operating parameters. Operators noted that the cost of a single total blackout—including damaged equipment and lost production—would have exceeded the cost of the powerMAX system.