200 kW Full-SiC DC/DC Converter

Projects targets

Development of an extremely compact, high efficient 200 kW traction DC/DC converter using SiC-power devices

Challenges

  • Low inductive commutation cell for fast swtiching
  • Integrated power modules
  • Extremely flat, small and high dV/dt driver
  • Multi phase operation for reduced ripple current
  • High performance ceramic highside capacitor
  • Small, accurate and EMI-immune current sensing
  • Low-volume, high energy power inductors
  • Integrated and optimized water cooling

Description

A central component of many electrified vehicles is the traction DCDC-converter. It’s task is to connect and convert energy between different energy storages, battery chargers (AC-chargers, fast DC-chargers), drive inverters and range extending sources. In modern car architecture, weight and volume are determinant factors. In this project, a DCDC-converter has been developed using SiC-Mosfets that allow a high switching frequency of 200 kHz and in the same way a high efficiency of more than 98.5%. The high switching frequency has allowed a dramatic size reduction of passive components leading to a record-breaking power density of up to 143 kW / dm³ and a weight of only 3.2 kg.

Results

Even though the costs of SiC-Mosfets are at the time of the converters development still much higher than conventional silicon solutions, it has been shown, that the use of wide bandgap technology results in superior technical properties and a dramatic reduction in volume and weight, leading to a cost reduction of the passive components. By saving material costs, the break even for SiC component costs is easy to achieve.

Project Partners

Fraunhofer Institute for Integrated Systems and Device Technology (IISB)

Panasonic Corporation Device Research Laboratory, Advanced Research Division

Project duration

2013-2014