Facing the threat of large-scale outages on the island of Grand Cayman, Caribbean Utilities Company chose SEL to fix failing bay controllers at its main substation. SEL’s solution saved the utility millions of dollars.

Caribbean Utility Thwarts Island-Wide Power Blackouts

Caribbean Utility Thwarts Island-wide Power Blackouts

This paper examines several common bus configurations, presents appropriate protection schemes for each configuration, and analyzes the protection scheme complexity, advantages, and disadvantages.

Bus Protection Considerations for Various Bus Types

In the early hours of the morning on a warm night in June, a group of engineers gathered in Georgia’s National Control Center. With quiet efficiency, they prepared to execute one of the most important tests the utility would ever perform, cutting the power to one of their most critical 500 kV transmission lines.

Innovation, Persistence, and a New Beginning

Two drastically different types of differential relays, one with a single set of very high-impedance inputs and another with multiple sets of low-impedance inputs, are available for bus differential protection. This paper discusses for each type of relay the concepts used, the pros and cons, and the importance that current transformer selection plays in applications.

Considerations for Using High-Impedance or Low-Impedance Relays for Bus Differential Protection

This course is designed for utility and industrial protection engineers and power system consultants. Students in the APP 487B course explore implementation of station-wide, low-impedance current differential protection and integrated circuit breaker failure detection using the SEL-487B Bus Differential and Breaker Failure Relay. Single- and three-relay applications for both basic and complex busbar arrangements are covered. Backup overcurrent protection, event recording, automation, and time-synchronization capabilities are discussed. Students will work directly with the SEL-487B Relay, performing hands-on communications, settings, and testing.

APP 487B: SEL-487B Bus Differential and Breaker Failure Relay

Busbar Protection

Bus protection products and systems provide complete primary and backup protection for all types of bus and switchgear arrangements.

Busbar Protection

Busbar Protection Relays

Overcurrent Protection Relays

System Components