Fraunhofer IZM Breaks Power Density Records
Highly integrated inverter with a power density of 500 kW/l, optimized for maximum power density. © Fraunhofer IZM | Volker Mai
What if you could fit the power of 680 horsepower into a package roughly the size of a water bottle? Researchers at Berlin's Fraunhofer IZM have done exactly that.
According to a press release from Fraunhofer IZM, the institute's Power Electronic Systems group, led by engineer Wiljan Vermeer, has developed an inverter that delivers 500 kilowatts of power within a volume of just one liter. Commissioned by Mitsubishi Heavy Industries (MHI), the device achieves 99 percent efficiency, outperforming common alternatives fivefold and beating current top-tier systems by a factor of 2.5.
Inverters are a core component of electric vehicles, converting battery direct current into the three-phase AC power that drives electric motors. The smaller and more efficient, the better, especially where space under the hood is tight.
Four engineering tricks made it possible. First, twelve silicon carbide MOSFETs are embedded directly onto the PCB, shrinking the electromagnetic footprint to just one nanohenry of inductance. Second, a flat extruded aluminum cooler with more than forty thin channels handles heat efficiently in a single-step production process. Third, laser-welded busbars eliminate screws, saving space and further reducing inductance. Fourth, specially configured NanoLam capacitors from PolyCharge, arranged alongside the busbars, keep the total DC-link inductance to just two nanohenries.
The result is an 800-volt drive system that sets a new benchmark in power density while keeping production costs moderate.