Are Virtual Protection Relays the Future of Protection and Control?
What if your protection relays lived on a server? Virtual Protection Relays (VPRs) are turning that idea into reality. The notion is futuristic, and if you work in protection engineering or relay testing it may seem ambitious, even risky. But the real question is whether VPRs represent the next step in protection and control. That’s worth examining with a clear-eyed look at how they work, what they demand, and how they perform.
Locating Protection Where IT and OT Converge
For decades, protection systems have relied on physical devices—first fuses, then electromechanical relays, and later microprocessor-based relays—to keep electrical faults from escalating into catastrophic failures of high-voltage assets. With VPRs, the relay becomes software running inside virtual machines created and managed by a hypervisor, which is the specialized system layer on the server that allocates CPU, memory, storage, and networking among multiple virtualized workloads. The physical relay chassis disappears, but the essential digital attributes engineered by original equipment manufacturers remain intact: proprietary logic, protection algorithms, and operational behavior.
The practical advantage is consolidation. A single high-performance server can host many virtual machines, each hosting a VPR, effectively behaving like an independent protection system. In principle, this shift delivers substation OT with the same or better protection performance while reducing the hardware footprint, streamlining upgrades, and lowering O&M costs.
Less Hardware, But Still a Lift
Those benefits, however, do not arrive by magic. VPR implementations begin with infrastructure that is both robust and deliberate. Servers need to be built for substation environments and comply with standards such as IEC 61850-3 and IEEE 1613, because substations can be hot, cold, dusty, and electrically noisy. Inside the server, processors must support virtualization, memory should be error-correcting to guard against bit flips, power supplies should be redundant, and thermal design must be capable of dissipating heat under sustained load. The storage layer matters as well; redundant independent drives provide resilience against failures and help keep the platform trustworthy when things go wrong.
None of this would matter without dependable communications, and that is where networking adds complexity. VPRs rely on digital protocols such as IEC 61850 GOOSE and sampled values, which in turn call for deterministic, redundant Ethernet topologies. Parallel Redundancy Protocol, defined in IEC 62439-3, helps guarantee zero recovery failover by sending traffic across twin networks simultaneously. Precision Time Protocol—IEEE 1588—keeps merging units and protection logic in tight temporal alignment so that decisions are based on a consistent view of the system. Clean time domains, disciplined network interface mapping, and careful segmentation between station bus and process bus become the invisible foundations of reliable operation.
A Mental and Operational Shift
Just as the infrastructure changes, the daily experience for engineers changes too. Instead of front panel indicators, physical cable and wiring terminations, and tactile buttons, interaction happens through network centric methods using HMIs and browser based dashboards.
The setup work blends IT and OT tasks—installing and hardening the hypervisor, provisioning and patching virtual machines, configuring storage and network interfaces, and enforcing cybersecurity policies. The cultural impact is real. Success depends on protection engineers and IT professionals working as peers, speaking each other’s language, and sharing ownership of design, deployment, and ongoing operations.
What About Speed and Reliability?
Performance is the question that most practitioners ask first, and rightly so: if the relay doesn’t trip quickly and predictably, nothing else matters. Comparative testing offers a reassuring picture. Depending on the fault type and magnitude, VPRs have demonstrated operating times that surpass electromechanical devices and even modern microprocessor-based relays; otherwise, their operation response is similar to traditional protection devices—well within credible protection.
Even when networks are loaded with substantial Ethernet traffic, VPRs have maintained reliable behavior so long as the architecture preserves deterministic paths and clean time synchronization. In other words, speed is not a problem; the challenge lies in the ecosystem that surrounds the relay: the servers that host it, the networks that carry its messages, and the multidisciplinary teamwork required to keep both in tune.
The Vision
The practicality argument is compelling when viewed through the lens of standardization and lifecycle management. Utilities grappling with aging infrastructure and tight budgets can replace fleets of disparate physical relays with a smaller number of servers running protection as standardized applications.
That consolidation simplifies upgrades, enables centralized patching and configuration control, and strengthens data-driven operations by unifying logs, settings, and evidence for compliance and analytics. It also lays the groundwork for future digital tools—simulation, integration, automated reporting—that are far easier to deploy on a virtual platform than on isolated boxes spread across a territory.
Bottom Line
Gains from VPRs come only to organizations that design with discipline and back their implementations with procedures, testing, and training that reflect the blended nature of the platform. Ultimately, the difference between a neat lab demonstration and field ready reliability is made by early pilots, strict adherence to applicable standards, and shared ownership between protection and IT teams.
A thoughtful path forward might start with a single substation, explicit success criteria for trip performance and failover behavior, and a joint runbook that covers architecture, roles, cybersecurity posture, test plans, and rollback.
Treat VPRs as promising but demanding; not magic, not madness, but a concept that could reward careful engineering and collaborative practice.
Further Reading & Source
This blog draws on insights and data from the paper “Virtual Protection Relay: Myth or Reality on this Generation?” authored by Jose Ruiz (Doble Engineering), Bryan Gwyn (Doble Engineering), and Montie Smith (formerly with Dell Technologies). For a deeper technical dive—including hardware specifications, setup steps, and detailed test results—you can access the full PDF here.
Have you piloted virtual relays or considered them for your P&C planning? Share your experiences—or your biggest concerns—in the comments. Let’s start the conversation!
Originally published in the The Relay™ Newsletter. Subscribe on LinkedIn.
