The electric car is really an electronic car; that it is viable today is a testament to the capabilities of semiconductors. Advances in energy storage technology may steal the limelight but the electronic systems that manage potential and kinetic energy – the battery and the drivetrain — are the real stars of the show.
While the holy grail of a “super battery” has proved elusive so far, semiconductors have steadily extended the lifetime of current batteries — and driving range — while monitoring potentially dangerous overcharge, over-discharge and over-temperature conditions.
Briefly, here’s what goes on under the hood: A DC/DC converter connects the high-voltage battery to the conventional 12-V vehicle power net; a DC/AC inverter uses the high voltage of the battery to drive the electric motor – either a single motor to drive an axle or several in-wheel motors — but also is used for regenerative braking, storing energy back into the battery. The connection of a high-voltage battery to the inverter also requires a reversible DC/DC converter in most cases.
Charging the battery requires it to be connected to the smart power grid; an AC/DC rectifier generates a DC voltage from the AC line, followed by a DC/DC converter to generate the right DC voltage for the battery pack. Along the way, there are various voltage levels and power factor corrections to contend with.
Ultimately, maximizing battery life and converting energy efficiently aren’t enough; system safety is paramount. Here, too, semiconductor intelligence has delivered.
For more on the building blocks of efficient transportation systems of the future – or to build your own set of electric wheels– read “System Solutions for Hybrid and Electric Vehicles.”