MUNICH, Germany — The Fraunhofer Institute for Solar Energy Systems (Freiburg, Germany) claims it has achieved a record efficiency for its inverter designed for PV generators. Key to the high efficiency are Silicon Carbide (SiC) power transistors from US vendor Cree, Inc.

Fraunhofer ISE is so far the first user for these innovative power transistors, explained Bruno Burger, head of the power electronics group at Fraunhofer ISE. "SiC transistors switch faster and show less forward resistance, compared to conventional components", Burger said. Hitherto, SiC components were used mostly to produce white LEDs.

The inverter, designed for a power range of up to 5 kilowatts, is characterized by an efficiency of 97.5 percent, the institute claims.

Besides the SiC MOSFETs, a novel inverter topology dubbed Heric was responsible for the high efficiency. Heric, for which a patent is pending, improves the efficiency by an additional percentage point, Burger said.

The institute plans to license the technology to industrial customers, Burger explained. However, the production will depend greatly on the availability of the semiconductors which presently are only in the prototype state.