How will the power transformer of today evolve to meet tomorrow’s demand?

In a world of immense power demand, decentralised energy sources and resilient energy communities, how will the power transformer – an already stable piece of technology – evolve? Yusuf Latief finds out.

As we move toward a climate-neutral future, almost every aspect of our power systems will need to be upgraded to accommodate renewable power sources, increased levels of flexibility, and a surge in demand as more consumers and prosumers increase their consumption of clean tech assets.

One of the most important pieces of this complex puzzle will be the transformer, an established technology that is already reliable.

But as electrification rates only continue to rise and more variable sources of energy come online, will keeping the transformer’s status quo be enough?

I’d argue not. The technology will have to improve; it is only a matter of when and how.

As digitalisation continues to prove the answer to the integration of renewables, so too will transformer technologies go digital, becoming smarter and more efficient.

Looking into this issue, in January 2024 researchers from the Rajshahi University of Engineering and Technology in Bangladesh published a technology review and technical framework for next-generation power grid transformers (NGPGT).

The paper, ‘Towards next generation power grid transformer for renewables: Technology’ cites a lack of centralisation, local monitoring, interoperability, authenticity and precise bi-directional flow as potentially limiting the application of current transformers for the modern and evolving energy system.

Their NGPGT is developed by introducing some features for addressing such challenges that current-generation transformers are still grappling with.

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Specifically, advanced technical features are theorised within the existing framework for transformers, including automatic condition monitoring, intelligent inverters, edge computing, automatic controlling and intelligent management.

In essence, the transformer of tomorrow becomes digitalised. The researchers say as much in their paper: “The next-generation transformer probably combines many sophisticated components, resulting in reliable operation in the transmission lines.

“In essence, this means that power systems have fully accepted digital technologies. This digitalisation has resulted in better capacities, efficiency and more sophisticated control over the entire energy distribution network.

“It incorporates consistent information security solutions, edge computing, cloud-based monitoring and other technical services.”

And while the theory behind this sounds great, the question yet remains: how will this look?

Well, one picture painted by a European project called STRATA is of the future digital transformer as a central node, found at the interface between energy communities and grid operators.

Project STRATA

Project STRATA – Smart Transformation for Resilience And community services Through digitAl grid layers – develops a new digital concept for the transformer at the medium and low voltage levels.

The key idea behind the project is to replace traditional distribution transformers with a ‘Smart Digital Node’ (SDN) that can act as a service centre for local energy communities and provide new distribution grid services and increased resilience, together with support for flexibility markets.

Kari Mäki, a research professor of smart energy systems with the VTT Technical Research Centre of Finland, says the main driver behind their research is the thought of how rapidly clean technologies have been coming online.

“A lot of technologies like PV panels, heat pumps and EV charging infrastructure is now being installed at the building level and has made it clear that there is actually very little automation at the moment on the low voltage grid. Practically no one knows what’s happening there.

“We have already, for a long time, been interested in the transformer because it’s a unit where you can manage a lot of things, but it’s also the closest node to the customer – and that’s exactly the level that needs to deal with EV charging and PV panels and everything else.”

The STRATA project looks at seven different use cases for the integration of a smart transformer as this central node.

These include grid management functions, resiliency against potential outages, local optimisation functions, local hosting capacity for distributed generation, services towards the local grid, services towards markets and, last but certainly not least, services for the local energy community.

The final use case studied by project STRATA is of significant interest.

Energy communities are increasingly on the rise throughout Europe and research into their development isn’t exactly novel. But the upgradation of transformers to better empower them isn’t an oft-cited headline.

STRATA’s SDN would be able to act as a service node for the local energy community, opening opportunities for community services such as peer-to-peer transactions as well as shared EVs, PV panels and batteries in close proximity to the SDN.

The community would be able to offer services to the grid and to markets, generating income while being self-sufficient.

“What we are proposing is a new model that hasn’t been fully developed yet,” says Mäki, who notes that regulation is a big consideration when it comes to this new type of transformer as well as to the various entities that will need to be in the loop, such as the grid operator, aggregator and service operator.

“Most energy community developments have been on the customer side with behind-the-meter use cases, because that’s where a lot can be done without necessarily asking the local grid operator.

“But transferring power from one customer to another through this type of transformer station means using the public network, which involves grid tariffs.

“So in that sense regulation is still a bit limiting, but we are of course also looking at the next steps for this.”

Technical capabilities

STRATA’s prototype development is based on MSc Electronics’ Hybrid Energy Supply System (HESS), which has already been applied for local off-grid communities.

Their next steps are to pilot the overall solution and each of its defined use cases under realistic circumstances.

Additionally, for STRATA’s energy communities use case, the project is more focused on the technical capabilities and thus excludes aspects such as user interfaces, operational models, submetering and billing issues.

So, while the project clearly has high potential, more work is yet needed. At the end of the road, it will be interesting to see how things pan out.

Said Mäki: “A big question for all of this is: who would pay?

“Who would own the unit and how? What would be the business model?

“It’s actually pretty interesting to think about it. Would it be a system in the future where we have a ‘transformer as a service’, where the grid operator is not owning but they are paying a monthly fee, and whoever is providing the service will also be able to sell the service to the community and to reserve markets?

“Something like this could be the way to do it. So we are considering this.”

Originally published on Enlit World.