TOKYO May 20 Toyota Motor Corp has
developed a computer chip for its gas-electric hybrid cars that
could boost fuel efficiency by 10 percent and allow the
automaker to install the hybrid system on more of its vehicles.
The maker of Prius hybrids and auto parts maker Denso Corp
have jointly developed a semiconductor using a silicon
and carbon compound that limits power loss and allows for a
smaller hybrid system, Toyota said on Tuesday.
"A key way to improve fuel efficiency is to improve power
semiconductor efficiency," Kimimori Hamada, a Toyota engineer,
told a media briefing.
Toyota's push in semiconductors highlights how carmakers'
competitiveness is increasingly tied to electronics rather than
to traditional mechanical engineering.
It also reveals the scope for further improvements in
gas-electric hybrid technology nearly two decades after Toyota
led the market with the launch of the Prius in 1997.
The new chip's silicon carbide compound is already used in
computer chips in trains and air conditioners, but this is its
first use in automobile power chips, Toyota said.
The battery of a hybrid vehicle captures energy from braking
that can aid the combustion engine and improve mileage. The
Power Control Unit (PCU) supplies electrical power from the
battery to the motor when the car is running and charges the
battery when the vehicle is braking.
Inside the PCU are power semiconductors, currently made from
silicon, that control the flow and the direction of electric
The silicon carbide chip reduces the amount of current lost
as heat and switches the current flow on and off more
efficiently, although costs are an issue. The silicon carbide
chip costs at least 10 times more than silicon, Hamada said.
About 20 percent of electrical power loss in hybrid vehicles
is currently associated with power semiconductors, he said.
The new chips will allow Toyota to cut the volume of the PCU
to one-fifth the current size and reduce the weight to about 4
kg from 18 kg, Keiji Toda, a Toyota engineer, said.
The size and weight reductions would save fuel and
potentially widen the range of cars that could be fitted with a
hybrid system, Toda said.
Toyota, which has achieved 5 percent gains in fuel
efficiency on prototype vehicles, plans to start installing the
chips in its cars around 2020, Hamada said, although it does not
expect to immediately achieve the targeted 10 percent fuel
(Reporting by Yoko Kubota; Editing by Edmund Klamann and Jane