Upgrading Relay Protection: Be Prepared for the Next Replacement or Upgrade Project

There are many advantages to upgrading old electromechanical (EM), solid-state, and first-generation numeric relays with modern numeric relays. Reliability increases because there is less direct wiring and interconnection wiring, and the reliability and security of multifunction logic and settings are improved with the next-generation user interface software. Remote input-output modules, remote analog/digital inputs, and thermal measurement capabilities have expanded protection, control, and monitoring. New protection and monitoring features improve power system equipment life and increase personnel safety. Maintenance costs are reduced, while internal watchdogs alert the user if the relay has a problem. Settings groups can be changed instantaneously to adapt to varying power-system requirements. Modern second-generation numeric relays offer a variety of secure communications capabilities for interfacing with smart-grid controls, supervisory control and data-acquisition systems, and business networks. Event memory is larger for more onboard, standardized oscillographs and event reporting. Relay security is in accord with the latest North American Electric Reliability Corporation (NERC) standards.