Driving gallium nitride technology forward in ALL2GaN

Premium PSU is an active partner in the European collaborative project ALL2GaN, which brings together 45 companies and institutions from 12 countries across 11 strategic application sectors. This ambitious initiative, funded by the European Union, aims to accelerate the industrial adoption of gallium nitride (GaN) as a key technology for achieving more efficient, compact, and sustainable power electronics systems.

The ALL2GaN project is structured around multiple work packages covering the full technological value chain: device development, packaging and integration, reliability, and real-world use cases. Within this framework, Premium PSU applies its strong expertise in railway converters to develop a bidirectional railway battery charger.

A Comprehensive Approach to GaN Advancement

The project focuses on improving the efficiency and reliability of GaN-based systems by addressing the following core areas:

GaN substrates and devices <100V
Solutions for lateral GaN devices and integrated circuits (≥650V)
High-performance, cost-effective RF GaN
Packaging and system integration
Reliability from component to system level
Smart and green applications

European-Level Collaboration

In April, Premium PSU actively participated in the M24 General Assembly of ALL2GaN, hosted at the Polytechnic University of Madrid. Over 100 representatives from across the consortium gathered to review progress and coordinate next steps. We joined technical discussions focused on energy, mobility, and communications—reinforcing our shared commitment to make GaN a cornerstone of Europe’s energy and digital transition.

Our representative, Miquel González, also joined a roundtable discussion where he shared project results, experiences, and insights on the practical challenges and current limitations of GaN technology. He also outlined key needs and future improvements required to further unlock GaN’s potential.

7.5 kW Bidirectional Battery Chargers for Railway Applications

As part of ALL2GaN, Premium PSU is developing two 7.5 kW bidirectional battery chargers for the railway sector. These are identified by the following product references:

BDS-7K4: Single-phase input
BDX-7K4: Three-phase input

Both units are designed to meet EN 50155 standards for electronic equipment on rolling stock and aim to exceed two key performance indicators:

Minimum efficiency of 94%
Power density > 500 W/l

In alignment with the project’s goals, the chargers are built using 200V, 600V, and 650V top-cooling GaN devices. For the three-phase model, 1200V top-cooling SiC devices are used in combination with GaN to overcome voltage limitations. This hybrid approach allows operation at higher voltages, while GaN compensates for the switching losses of SiC devices.

Initial prototype testing has shown outstanding results:

BDS-7K4 achieved 97% total efficiency
BDX-7K4 reached 97%

Although the difference is just 0.27%, it highlights the advantage of GaN in terms of efficiency and power density. Notably, GaN devices operate at 100 kHz switching frequency, compared to 64 kHz for SiC, reinforcing GaN’s superior performance in high-frequency applications.