Toyota Experimental New hybrid Semiconductor Material

It is said that the new testing technology in Toyota could make hybrids and other vehicles with electric powertrains more efficient. Using a "Camry" hybrid prototype and a fuel cell bus, Toyota Motor Corporation will bring a brand new technology to the streets of Japan for testing this year. The yearlong experiment in Japan will judge the performance of the new power semiconductors that use a silicon carbide (SiC) material, fitted to a Camry hybrid saloon prototype and a hydrogen fuel cell-powered bus.

Power semiconductors are found in the power control units that control the motor drive power in hybrids and other vehicles that use an electric powertrain. These units regulate the use of electricity, send power from the battery to the motors when the car is being driven, and recharge the battery with energy that’s accumulated when the car is stopping or decelerating.

The type of semiconductors used at present account for about 20% of a vehicle’s electrical losses, therefore making them more efficient is potentially a good way to increase the efficiency of the complete powertrain.

If we compare to the current silicon power semiconductors, the new, high-quality SiC type create less resistance when electricity flows through them.  This technology has been developed jointly by Toyota, Denso Corporation and Toyota Central R&D Labs, as a result of an extensive research and development project.

In the hybrid prototype, the automaker is installing SiC power semiconductors (transistors and diodes) in the PCU’s internal voltage step up converter and the inverter that controls the motor. It will collect data, including PCU voltage and current, driving speeds, patterns and conditions, such as outside temperature.

Comparing this information with data from the silicon semiconductors now in use, Toyota will evaluate the level of effectiveness improvement achieved.

The road test will take place mostly in Toyota City over a period of about a year from early February.

Toyota has recently started collecting operating data from a fuel cell bus that is in regular commercial operation in the city.

The information gained from the tests will be reflected in Toyota’s development program, with the goal of putting the technology to practical use as soon as possible.

http://www.electric-vehiclenews.com/2015/01/toyota-to-trial-new-sic-power.htm