Improving reliability and performance of transformers for power distribution units in data centres

Data centres are rapidly becoming one of the largest energy consumers, driving the need for efficient, reliable and thermally optimized power systems. Power Distribution Unit (PDU) transformers play a critical role in delivering power to IT equipment while ensuring high performance and uptime. However, harmonic currents from non-linear loads in electronic equipment present a significant challenge, causing heat generation, reduced efficiency and potential transformer failures. This study investigates thermal aspects of designs for triangular core PDU transformers compared to traditional rectangular core transformers. Two prototypes rated 300 kVA were produced using aramid-based insulation systems in thermal class 220°C. They were tested for temperature rise under various load conditions. The high thermal class insulation system may be a tool for mitigating the winding overheating up to a certain level of harmonic content. Any higher harmonic loads may need to be addressed by modified designs or transformer de-rating. By improved thermal management and offering space-saving benefits, the aramid insulated transformers with triangular core design demonstrate their potential to meet the growing demands of high-power density data centres. These findings pave the way for more sustainable, efficient, and reliable data centre power solutions.