The IEC-61850 communication protocol is gaining recognition as the future of power system protection, automation and control, offering a transformative approach to substation design and operation. Various utilities have explored various ways to leverage IEC-61850’s flexibility. This presentation showcases real-world examples demonstrating how IEC-61850 can significantly address complex issues in existing substations with traditional protection systems, enabling additional functionality without the extensive wiring changes previously required.

This presentation details a practical application where IEC-61850 was used to resolve an existing problem and enhance system performance. The application involves five distribution lines connected to a common bus, each line sharing poles for part of the feeder. Multiple distribution lines on the same poles add complexity to the protection system, necessitating cross-interlock schemes and staggered reclosing logic to maintain proper selectivity. While the partnered utility has already standardized on a cross-interlock scheme using hardwired I/O and applies staggered definite-time delays for reclosing on each circuit, this site predates this standardization, so the hardwired I/O cabling was not installed.

To address this, Burns and McDonnell and the partner utility chose to adapt their cross-interlock scheme from hardwired I/O to IEC-61850 GOOSE for this site. This transition eliminated the need for additional control cables and terminations on each device and enabled real-time sharing of fault current magnitude between feeder relays. Custom logic was also developed for each feeder relay to enable staggered reclosing based on fault current magnitude, rather than a fixed delay.

In collaboration with the utility, new cross-interlock and staggered reclosing logic using IEC-61850 was implemented and rigorously tested in the Burns & McDonnell Atlanta laboratory to ensure it met performance expectations. The successful results highlight the advantages of making such changes without additional wiring, thus significantly reducing costs and implementation time. Moreover, the programmable logic capabilities of IEC-61850 underscore its value in enhancing reliability and facilitating a smoother transition to a fully modernized grid.

 This presentation will also include a lab tour (the approach here will vary depending on audience size), and a brief demo of various approaches being taken in the industry, with the goal of highlighting the endless possible approaches that can be taken!

Biography:

Patrick Legarreta is a Staff Electrical Engineer with Burns & McDonnell with four years of experience in the industry. He is a member of the Protection Applications group within Burns & McDonnell, specializing on topics such as IEC-61850 implementation and testing, Arc Flash studies, coordination studies, harmonics mitigation, etc. He has a wide range of experience across multiple levels of IEC-61850 implementation and testing, ranging across all major relay vendors and with varying levels of implementation (partial implementation, full implementation, and centralized protection). Patrick also leverages his passion for VBA to identify and implement large scale automation tools. He is currently digging into the field of utilizing HIL testing to evaluate both system impacts of various harmonics sources and "digital twin-esque" approaches for black start strategies, as well as testing virtualized protection systems. He completed a B.S. in Electrical Engineering at Kennesaw State University.