Protection relay coordination is one of the most critical aspects of electrical power system design. Modern switchgear installations rely on intelligent protection relays to detect abnormal operating conditions and isolate only the faulty section of the network while maintaining service continuity to healthy circuits. Proper relay coordination minimizes equipment damage, reduces downtime, enhances personnel safety, and improves overall system reliability.
In electrical power systems, Current Transformers (CTs) and Voltage Transformers (VTs) — collectively known as instrument transformers — play a vital role in both metering and protection. They form the bridge between high-voltage power circuits and low-voltage measuring and protection devices, enabling safe, accurate, and reliable system operation.