The Future of Protection Engineering Is Digital | Andrea Bonetti, Megger & Cédric Harispuru, Siemens

According to Cédric Harispuru of Siemens and Andrea Bonetti of Megger, a high fidelity digital twin of a protection relay and a digital twin of a relay test set can co-simulate and test each other in a fully virtual closed loop, with no physical hardware. Bonetti says that, as far as he knows, only two companies, Siemens and Megger, have released such products. The next step, they argue, is IEC 61850-based interoperability between vendors, while scaling today’s solutions already shortens project time, speeds up troubleshooting and supports training.

Recorded at CIGRE 2026 in Paris for the APC Media Power Panel.

What You Will Learn

• What a digital twin of a protection relay and a test set is
• How co-simulation allows relays to be tested virtually
• Why Siemens and Megger describe their approach as pioneering
• How a training institute gave every student a virtual relay and test set
• Why IEC 61850 interoperability between vendors is the next step

Meet the Experts: Cédric Harispuru (Siemens) and Andrea Bonetti (Megger)

Cédric Harispuru works at Siemens in Germany, representing the protection relay business. He is Global Product Lifecycle Manager, especially for the SIPROTEC Digital Twin.

Andrea Bonetti is a Senior Specialist at Megger. He started as a high voltage protection engineer and has spent the last 10 years at Megger, working on test equipment for protection relays, both for IEC 61850 digital communication and analog applications.

What Is the Joint Paper About?

Bonetti explains that there is always a protection relay and a relay test set, and they usually come from two different companies because responsibilities differ. Their paper presents a pioneering technology based on high fidelity digital twins: a realistic copy of the protection relay and a realistic copy of the test set.

The paper shows how the two twins interoperate, or in technical terms co-simulate. The result is that a relay can be tested with a test set virtually, not physically, in a virtual environment.

What Are Digital Twins and Virtual Closed-Loop Testing?

A digital twin is a software replica that mimics the behavior of a physical device. Co-simulation means two or more simulation models run together and exchange data. In virtual closed-loop testing, the virtual test set applies test conditions to the virtual relay, and the relay’s responses feed back into the test, as they would with physical devices.

These are general definitions added for readers. The speakers describe the twins as realistic copies that can interoperate and test each other.

Why Is This Technology Considered Unique?

Harispuru says digital twins are a trend topic entering the power industry. Siemens has been a pioneer in bringing the digital twin to the protection relay, and together with Megger in bringing virtual closed-loop testing and virtual test sets. He notes that many other papers at CIGRE this year, including some from universities and customers, also mention digital twin usage.

Bonetti adds that when Siemens first asked whether Megger was interested, his reaction was: “what is a digital twin?” He calls Siemens’ effort impressive because it invests in a technology where you don’t know if it will pay back. As far as he knows, only two companies, Siemens and Megger, have released digital twin products. He hopes more will follow, and says customers want that too.

How Did the Siemens and Megger Cooperation Work?

Harispuru describes the path from idea to ecosystem:

• Meeting at conferences and building a relationship
• Sharing the idea and seeing the interest
• Selling the idea to internal management
• Involving R&D teams on both sides
• Testing, then writing papers around the world

By his estimate, they have co-authored more than 20 papers over the past five years. He describes the result as a first ecosystem around digital protection testing, and says it will not be the last paper.

What Is the Real-World Outcome? Training Without Hardware

For Bonetti, the most important outcome, besides the released product, is a training course on relay protection commissioning held in Sweden last year. It was organized by a third-party training institute, not by Megger or Siemens.

The institute wanted every student to have their own relay and test set. With physical hardware that would be impractical: too many devices, too expensive, hot fans in the room and cable connections that can go wrong. With digital twins, he says, “there nothing happened,” with not one single crash. He also calls it “the best toy you can give to a protection engineer,” because there is no lab and no wiring.

How Do Digital Twins Shorten Project Time?

From Siemens’ perspective, Harispuru says the company started using its digital twin earlier to scale usage across the globe. More projects now use it to:

• Shorten project execution times
• Support faster troubleshooting
• Enable better training

The collaboration with Megger, through virtual closed-loop testing, extended the scope. It lets users work with a combination of products, a relay and a test set, which answers an early limitation: “what about the rest of the system?”

What Is the Future of Digital Twins and IEC 61850 Interoperability?

Bonetti points out that both companies work with IEC 61850, the standard for digital technology in power system protection. The future, he argues, must allow digital twins from different vendors to interoperate. Today everything is proprietary between Siemens and Megger. In the future, the interface between the twins must be described, while the companies remain competitors.

Harispuru adds a second priority: scaling the use of what already exists. He says digital twins help the industry build substations faster and speed up the integration of data centers into the grid. Many more users could adopt the technology, and he expects more to “jump on the train.”

CIGRE 2026 Reflections: Networking Across Committees

Harispuru values face-to-face feedback from partners and customers and the knowledge sharing between study committees. Bonetti highlights the work of delegates who review hundreds of papers, and notes that people from other committees, including A3, came to the booth to ask about digital twins, even though the paper was presented in B5.