Power electronics

New materials for power devices and advanced and novel power devices

At the heart of all power electronics are semiconductors. Traditionally components are based on SiC or silicium, but by replacing this by for instance GaN (Gallium Nitride) materials these switches can become even more efficient and faster. In this way we can make the converters much smaller while still having a higher yield. Within EnergyVille we try to make GaN switches in an integrated way so that we end up with an integrated component that contains all necessary switches for 1 converter. We also look at the package of the component in order to dissipate the heat as efficiently as possible.

Efficient and reliable power convertors

Within EnergyVille, we develop power electronics converters that support the roll-out of the LVDC grid, efficient drives and battery interfaces. The focus is mainly on high step-up and high step-down DC/DC conversion where reliability, efficiency and compactness are key parameters. Application areas can be found in Point-Of-Load (POL) and integrated Module-Level Converters (MLC) for Building Integrated PhotoVoltaics (BIPV). Climate chambers are available to increase the thermal stress, thereby emulating extreme environmental conditions where the converters might operate. Aside from this we have set-ups to accurately measure yield.

Magnetic components for wide bandgap power converters

Nowadays, due to the increase of power electronics and energy use, almost 30% of all the electrical power is transported via a power converter, where magnetic materials are used in motors, reactors, inductors, filters, transformers, etc. Moreover, with the introduction of novel Wide Bandgap semiconductors (Gallium Nitride, Silicon Carbide, etc.), higher frequency operation has been demanded from the magnetic components. Therefore higher and more complex challenges have been raised to the performance of transformers and inductors in electric systems. Consequently, we are working on the characterization, modelling, and optimization of magnetic components for power converters achieving high efficiency, compact size and a good operation under the conditions of these novel semiconductors.

DC Nanogrids

Although electrical power networks in buildings and districts have been for about a century equipped with AC technology at 50 or 60 Hz, the energy transition is putting into question whether that is still the right choice. The transition to decentralized production, energy-efficient technologies and the electrification in heating and transportation all contribute to the question whether the current “lock-in” of AC technology for building technologies is still justified. EnergyVille is investigating low-voltage DC technology and the potential safety concerns. To do this, a representative building-level bipolar DC nanogrid (as opposed to the wide area microgrids) was set up in the Home Lab of EnergyVille I. For this we now mainly focus on protections and a stable and flexible way of managing the DC nanogrid.