ROHM will be providing full SiC power modules to the VENTURI Formula E team in the FIA Formula E 2017–2018 (season four), the leading racing event for electric vehicles which will start on December 2nd and 3rd in Hong Kong. This module will support further improvements in the machine’s performance under racing conditions.

As the leading developer of SiC power devices, ROHM became VENTURI’s official technology partner in season 3, and provides the world’s most advanced SiC power devices used in the inverter, which is the core of the electric vehicle powertrain.

The inverter for season four features embedded full SiC Power module, making it 43% smaller and 6 kg lighter than the inverter for season two.

Inverter comparison (click on image to enlarge)

Formula E is an all-electric-powered FIA (Fédération Internationale de l'Automobile) championship that began in 2014. The series has expanded to cities around the world which has to date included metropolises such as Hong Kong, Berlin or New York and champions a clean environmental approach that does not use fossil fuels.

The key to victory in this racing series for the drivers is to use power as efficiently as possible by getting the most performance out of the stored energy. The advancement in Formula E technology is expected to filter through developments to general-use electric vehicles.

Although this motorsports event is still in its infancy, it already enjoys the participation of automotive manufacturers from around the world and major automobile manufacturers including those from Japan have declared their intention to join the race.

For many years, ROHM has provided a highly varied lineup of products such as power supply ICs and various control ICs, along with discrete products such as power devices, current detection shunt resistors and so on for use in automobiles.

ROHM is pushing forward with the latest cutting-edge development of SiC power devices, which are expected to realize dramatic loss reductions compared to conventional Si (silicon) power devices. These power devices will be used more and more on electric vehicle (EV) motors and inverters.

Franck Baldet, CTO, VENTURI Formula E Team stated: “The Formula E is the only motorsports event for testing the latest technology in next-generation electric vehicles. We are extremely happy about our technical partnership with ROHM in the area of power management, which is the foremost key to the Formula E race.

“For season 4, by adopting a full SiC power module, we were able to bring to reality a lightweight inverter that requires only a minimum amount of space. By using the latest technology, I expect that we will be able to dramatically reduce our lap times, and I hope that we can continue to move forward with revolutions in technology through our partnership with ROHM,” concluded Baldet.

Kazuhide Ino, Group General Manager of Power Device Production Headquarters, ROHM Co., Ltd. added, “ROHM has been providing products for many years for today’s constantly evolving automobiles, with quality as our main advantage. This is currently a field in which we would like to give our special attention; and semiconductor devices are certain to play a crucial role in recent hybrid and electric automobiles.

“The SiC power device that we are providing for the Formula E racing car is one example. We provided SiC-SBDs in season 3 last year (2016–2017), but this year we provide full SiC power modules that combine SiC SBD and SiC MOSFET.

“These modules will contribute to improve vehicle performance. I hope that we can continue to contribute to society through the efficient conversion of energy in a wide range of industries and fields, starting with electric vehicles,” stated Ino.

The Advantage by Using SiC Products

The SiC power module used in the inverter of the VENTURI Formula E team racing car achieves a large power throughput, owing to the development of a new package with an improved internal module structure, as well as an optimized thermal management.

(click on image to enlarge)

Compared to conventional IGBT modules with similar current ratings, this module reduces switching losses by 75% (at a chip temperature of 150°C). This contributes to the energy efficiency for the whole application.

Also, having more compact peripheral components throughout the high-frequency drive, as well as the effect of reductions in switching losses contributes to a more compact cooling system as well.

By using this full SiC power module in the inverter section (the powertrain core), it makes the inverter 43% smaller and 6kg lighter than in season two. Even compared to the previous inverter used in season three, it is 30% smaller and 4kg lighter.

About Formula E

Held since 2014, the Formula E is the world’s first formula championship for electric cars, and is organized by the  ‘FIA’ (Fédération Internationale de l'Automobile), the organization responsible for the Formula One World Championship (F1) and the World Rally Championship (WRC). This event serves as a proving ground for the research and development of electric vehicles, and stimulates social interest in these cars.

Compared with conventional motorsports in which cars with internal combustion engines compete, the Formula E uses solely electrically-driven cars with very quiet drive noise and no emissions. Because of this, the races can be held on public courses in urban areas. Season four of the Formula E will open in December 2017 in Hong Kong, and races are planned to be held in Marrakesh, Santiago, Mexico City, São Paulo, Rome, Paris, Berlin, Zurich, New York and Montreal, for a total of eleven venues.