Work on vPAC (Virtual Protection, Automation and Control) is spread across several kinds of organizations, and the split between them is usually pretty clean. The IEC writes the standards. CIGRE does the groundwork and collects operating experience. The vPAC Alliance defines a cross-vendor reference architecture, and LF Energy builds the open-source implementations. There is no standard called “vPAC.”
IEC: The Standards
The International Electrotechnical Commission (IEC) writes the standards themselves: the normative documents everything else refers back to. Every digital substation, and with it every vPAC implementation, is built on the IEC 61850 series. Inside the IEC, that series belongs to Technical Committee 57 (Power Systems Management and Associated Information Exchange), and inside TC 57, Working Group 10 owns it.
WG 10’s Virtualisation Task Force deals with exactly this question: what does virtualization do to the standard? The sticking point is modeling. How do you describe a virtual IED, and the compute platform underneath it, in the Substation Configuration Language (SCL) so that a virtualized installation ends up fully documented and vendor-independent? Until that is settled, engineering a vPAC substation stays partly vendor-specific, and a good chunk of the benefit goes with it.
Three more standards matter alongside it: IEC 62351 for the cybersecurity of communication, IEC 62443 for systems and components, and IEC 61850-3 for the environmental requirements the hardware has to meet.
CIGRE: Groundwork and Operating Experience
CIGRE (the International Council on Large Electric Systems) is an international technical association for the power industry. It does not publish standards. It publishes Technical Brochures: the state of the art, plus what grid operators have actually seen in service. What ends up in a brochure usually finds its way into standards and specifications later on.
That work sits with Study Committee B5 (Protection and Automation). One working group currently does most of the vPAC work.
WG B5.84
The leading CIGRE activity for vPAC is WG B5.84, titled “Recommendations and constraints for development and interfacing of virtual Intelligent Electronic Device implemented in Protection, Automation and Control Systems.” It develops recommendations for grid operators on how to specify, configure, test, and maintain virtual IEDs and covers both VM-based and container-based implementations.
IEC TC 57 and CIGRE SC B5 maintain a Category A liaison, allowing results from the B5 working groups to feed directly into standardization activities.
vPAC Alliance: The Reference Architecture
The vPAC Alliance is an industry consortium of grid operators, protective relay vendors, and server and software suppliers. It was founded to define an open, interoperable architecture for virtualized protection and control with cybersecurity built in from the start.
The Alliance has produced shared specifications, reference architectures, and interoperability testing between products from different manufacturers.
The Alliance does not write standards. Instead, it addresses a different challenge: how existing standards can be assembled into a practical system and where interfaces must be defined more precisely for interoperability. Welotec, part of the Westermo group since 2025, is a member.
LF Energy: The Open-Source Implementation
LF Energy is an open-source foundation under the umbrella of the Linux Foundation. It provides licensing frameworks, development processes, and technical steering committees, but it does not prescribe architecture.
For the digital substation, the most relevant projects are SEAPATH as a virtualization platform for vPAC applications, CoMPAS for IEC 61850 configuration, and FledgePOWER for protocol conversion.
CoMPAS uses OpenSCD as its SCL editor front end, but OpenSCD is a separate community project that originated at OMICRON and is not governed by LF Energy. Welotec, part of the Westermo group since 2025, is also a member of LF Energy.
UCA International Users Group: Conformance Testing
The UCA International Users Group runs conformance and interoperability testing for IEC 61850. It also maintains the Tissues database, where questions of interpretation around the standard are documented and resolved.
When it comes to the practical interoperability of virtualized applications, this is where theory is validated against real-world implementations. The Westermo group, including Welotec, is a member.
The Roles at a Glance
| Organization | Type | Role in vPAC | Main Outputs |
| IEC - TC 57, WG 10, Virtualisation Task Force | International standards body | Writes the standards and defines how virtual IEDs are modeled in SCL | IEC 61850 series, IEC 62351, IEC 61850-3 |
| CIGRE - SC B5, especially WG B5.84 | International technical association | Develops groundwork, recommendations, and operating experience | Technical Brochures, including TB 891; ongoing work in WG B5.84 and B5.77 |
| vPAC Alliance | Industry consortium | Defines the reference architecture | Specifications and interoperability tests |
| LF Energy | Open-source foundation | Develops implementations | SEAPATH, CoMPAS, FledgePOWER, and related projects |
| UCA International Users Group | User association | Tests conformance and interoperability | Certification programs and the Tissues database |
| IEEE (PES / PSRC) | International standards body | Develops base technologies and protection guidelines | IEEE 1588 (PTP), IEEE 1613, PSRC special reports |
| EPRI | US research institute | Runs vendor-neutral benchmarks and field trials | Test frameworks and operational best practices |
| ENTSO-E / E.DSO | Grid operator associations | Define operator requirements and European application profiles | Interoperability profiles and TSO/DSO roadmaps |
| NIST | US standards agency | Defines smart grid and cybersecurity frameworks | NIST SP 800 series and Smart Grid Interoperability Framework |
Table 1 — Organizations active in vPAC standardization, interoperability, implementation, and supporting technologies.
Facts at a Glance
- There is no IEC standard named “vPAC”
- IEC develops the normative standards, including IEC 61850
- CIGRE provides technical groundwork and utility operating experience
- The vPAC Alliance defines an interoperable reference architecture
- LF Energy develops open-source implementations such as SEAPATH and CoMPAS
- The UCA International Users Group validates interoperability and conformance
- Additional supporting organizations include IEEE, EPRI, ENTSO-E, E.DSO, and NIST
In short: CIGRE does the groundwork, the IEC turns it into standards, the vPAC Alliance defines the architecture, LF Energy writes the code, and the UCA International Users Group checks that the result actually works together.
