Can’t live without it
by Alex Apostolov, Editor-in-Chief
Modern electric power systems are no longer defined solely by transformers, circuit breakers, and transmission and distribution lines. They are increasingly shaped by communications networks that determine how quickly intelligent, and securely protection systems can respond to disturbances.
Communications have evolved from a supporting utility function into a foundational layer of protection engineering itself. In many respects, the future reliability of the grid will depend as much on data exchange as on electromechanical infrastructure.
Historically, protection systems operated locally and independently. Relays made decisions based on measurements from a single substation or feeder, with minimal external coordination. While dependable, these approaches were inherently limited by geography and latency. Today’s power systems, however, are more dynamic and decentralized. Renewable generation, inverter-based resources, microgrids, and distributed energy systems have introduced bidirectional power flows and rapidly changing operating conditions. Protection must therefore become more adaptive, coordinated, and communication aware.
Digital substations represent one of the clearest examples of this transformation. By replacing extensive copper wiring with Ethernet-based process buses and IEC 61850 communications, digital substations enable protection devices to exchange sampled values and event information with extraordinary speed and precision. Intelligent electronic devices (IEDs) can now share real-time measurements over fiber-optic networks, dramatically reducing installation complexity while improving interoperability and diagnostics. The substation is no longer merely a collection of isolated relays; it has become a coordinated digital platform.
The rise of Routable GOOSE (R-GOOSE) further extends this philosophy beyond the substation fence. Traditional GOOSE messaging was confined to local-area networks, but R-GOOSE enables protection signals to travel securely across wide-area IP networks. This capability opens new possibilities for pilot protection, inter-substation tripping, and wide-area system integrity protection schemes. Utilities can now design protection architectures that span entire regions rather than individual substations. In effect, communications networks are becoming part of the protection itself.
Equally transformative is the emergence of centralized protection and control. Instead of assigning protection intelligence exclusively to individual relays, centralized architectures aggregate data from multiple bays or substations into high-performance computing platforms. These systems can execute coordinated protection algorithms using system-wide awareness rather than isolated local measurements. Such architecture promises improved selectivity, simplified engineering, and reduced hardware redundancy. However, they also introduce a profound dependency on reliable, deterministic communications. Without resilient networking, centralized protection cannot fulfill its potential.
This dependency has increased interest in advanced communication technologies such as private 5G networks. Although wireless technologies were once viewed skeptically in protection applications, modern 5G systems offer ultra-low latency, network slicing, and enhanced reliability that may eventually support critical grid functions. Utilities are exploring private 5G deployments for substation connectivity, distributed automation, and field device integration. The appeal is clear: a flexible, scalable communication infrastructure capable of supporting millions of intelligent devices across geographically dispersed systems.
Yet enthusiasm for 5G must be balanced with realism. Protection engineers have traditionally valued deterministic performance above all else. Fiber-optic communication remains the gold standard for high-speed protection because of its predictability and immunity to interference. Wireless technologies, even advanced ones, must prove that they can consistently meet the stringent dependability and security requirements of protective relaying. A single delayed or lost packet can have consequences far more serious than a dropped phone call.
Communications also play a pivotal role in distribution automation schemes such as FLISR – Fault Location, Isolation, and Service Restoration. FLISR systems rely on rapid communication among switches, controllers, and protection devices to isolate faults and restore service automatically within seconds. As extreme weather events and grid stress become more common, utilities increasingly view self-healing distribution networks as essential rather than optional. Here again, communications are not merely enabling operational efficiency; they are directly improving system resilience and customer reliability.
The modernization of protection systems therefore demands a broader mindset from protection engineers. They must understand not only fault currents and relay coordination but also cybersecurity, networking, latency management, and communication protocols. The boundaries between power engineering and information technology are rapidly disappearing.
Ultimately, communications are becoming the nervous system of the modern electric grid. Digital substations, R-GOOSE, centralized protection, FLISR, and 5G collectively signal a transition from isolated protection devices toward fully interconnected protection ecosystems.
“The biggest challenge is resisting change.”
Doyle Beneby, President and CEO, CPS Energy
