New tech promises faster, smarter EV charging stations

With sales of electric vehicles (EVs) surging by 24,9% in the European Union in the first half of 2025, the reliability and performance of charging networks will be key to transport electrification. Traditional charging stations, reliant on bulky copper-and-steel transformers, face significant challenges in scalability, cost, and efficiency. But a groundbreaking innovation—solid state transformers (SSTs)—could change the game entirely.

SSTs are advanced power electronic devices that replace conventional transformers with semiconductor-based technology. Unlike their traditional counterparts, SSTs are smaller, lighter, and far more efficient, making them ideal for next-generation EV charging stations.

Yi Hao, a PhD researcher at the Eindhoven University of Technology (TU/e) and part of the European E2GO consortium, is the inventor of a new SST concept. The design aims to reduce energy loss, improve safety, and integrate seamlessly with renewable energy sources. 

SSTs: a leap for EV charging

As in any other electrical circuit, a transformer is a component that safely delivers electrical current. In this case, it provides electricity from the grid to cars, stepping it down from high voltage to a usable level. “The transformer ensures safety between the grid and the car. Think, for example, that if there is a lightning strike on the grid, it makes sure the shock doesn’t affect the cars connected to it. Or, if one of the charging points within a station is faulty, it ensures that the others don’t get affected,” explains Dongsheng Yang, an assistant professor at the TU/e and lead of the E2GO consortium.

SSTs replace traditional copper-and-steel transformers with a combination of power electronics and high-frequency magnetic components. Using advanced semiconductor materials such as silicon carbide (SiC), they convert power much more efficiently while achieving electrical isolation through compact high-frequency transformers.

Furthermore, the SST concept proposed by the E2GO consortium offers a more compact, modular architecture than conventional transformers used in EV stations. This compactness enables easier scalability—multiple modules can be seamlessly connected to increase power capacity or expand the number of charging points.

More importantly, the new SST integrates a balancing circuit, reducing the need for additional power conversion stages. Simplifying the energy transfer path reduces hardware complexity, cuts system costs, and improves overall efficiency. As a result, the charging-station architecture becomes both simpler and more energy-efficient, with significantly lower conversion losses at each step.

Grid stability

Grid capacity is particularly an issue in the Netherlands, hindering the deployment of more EV charging points. Fast-charging stations draw large amounts of power, which can strain local grids. "We need smarter architectures," underscores Yang. "This includes integrating battery storage and renewable energy to reduce peak demand on the grid."

SSTs can help stabilize the grid. "With SSTs, we can connect AC and DC systems, making it easier to incorporate renewable energy and even vehicle-to-grid (V2G) technologies," explains Yan. This flexibility is crucial as grids become more complex, balancing traditional power sources with wind, solar, and battery storage.

Enabling efficient charging 

The E2GO consortium comprises nine European partners and is a Marie Sklodowska-Curie Doctoral Network project funded under the European Union Horizon support scheme. In addition to other academic institutions, such as the Portuguese University of Minho and the Danish Aalborg University, power solutions company Delta Electronics, and semiconductor manufacturer Infineon Technologies are also part of E2GO. 

Yi Hao is one of the PhD candidates in the consortium. At the moment, he is working on the practical application of research at the Polish branch of Delta Electronics. "Working in industry gives me insights into real-world engineering challenges. It’s not just about theoretical research—it’s about making technology that works in the field," adds Hao. 

The team is now fully focused on laboratory validation and system-level testing under extreme conditions. Hao is also in the process of filing a patent for the SST technology to protect its innovative architecture. If successful, SST-based charging stations could reach the market within three to five years. “We’re already in discussions with manufacturers,” says Yang. “The goal is to make fast, efficient, and scalable charging a reality for everyone.”