Under the name “Dauerpower”, the Fraunhofer Institute for Reliability and Microintegration has presented an inverter for electrically powered sports cars that processes high amounts of energy with low inductance in the smallest of spaces. The inverter was developed in collaboration with Porsche and Bosch and has a peak efficiency of 98.7 percent, according to Fraunhofer IZM. Over long periods of time, the continuous power inverter provides an output of almost 600 kilowatts; for short-term power peaks, it even achieves values of 720 kilowatts or 979 hp.
The basis for the performance of the continuous power inverter is the use of silicon carbide (SiC) transistors. “Compared to conventional silicon transistors, silicon carbide semiconductors are characterized by significantly higher temperature resistance, lower semiconductor capacitances and reduced on-state resistance with the same semiconductor area. They therefore offer the potential to significantly reduce switching and conduction losses,” says Dominik Seidenstücker, who played a leading role in the development.
In order to make the system particularly compact, DC-Link capacitors with PolyCharge NanoLam technology were also used, according to Fraunhofer IZM. A special PCB process, in which the semiconductor modules are embedded, further increases the efficiency of the system. Dominik Seidenstücker: “PCB embedding enables us to reduce the distance between the forward and return conductors and thus reduce the leakage inductance. The lower leakage inductance of the module means that we can switch faster. This in turn reduces the losses in the semiconductor once again. The technology also enables cost-effective mass production.
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