Secure Protective Relaying

Prescient is prepared to recommend enhancements that will improve the performance of protective relaying schemes.

Description of Services

Using our proprietary, industry-leading method of analyzing protective relay schemes, we evaluate client’s systems to determine their efficacy. We have examined significant events around the globe, and recommend actions to prevent similar occurrences.

Deliverables

Assessment of the security of client’s protective relaying schemes.
Assessment of the dependability of client’s protective relaying schemes.
Cost effective enhancements to simultaneously increase security and dependability.
Methods to prevent unwanted events, such as all transformers tripping offline at a substation.

Why Use Our Services?

Traditional protective relay applications are designed to race to the finish. The first protective relay that issues a trip command opens the circuit breaker, which clears a short circuit. Two protective relays are applied for protection of each transmission system element. There are several concerning aspects to this traditional approach.

The first concern is failure to trip. This concern was resolved by installing two protective relaying schemes in transmission applications.

The second concern, inadvertent tripping, remains an issue. Prescient’s approach to eliminating inadvertent tripping is to recommend the utilization of voting logic. With microprocessor-based protective relays, voting logic is achievable because each protective relay receives all the voltage and current inputs needed to create inputs to logic tables.

A third concern is breaker failure detection at neighborhood substations. Prescient has developed schemes that ensure only one transformer trips, rather than all transformers, when a distribution feeder breaker fails to open.