Zytek electric drivetrain enters production for smart ev

AUTO-INDUSTRY NEWS, LONDON ENGLAND - - An electric drivetrain developed by the Lichfield-based specialist company Zytek has allowed DaimlerChrysler to introduce “Europe’s first high quality, high efficiency electric commuter car”, the new smart ev (electric vehicle) shown at the British International Motorshow, which provides zero tailpipe emissions and fuel costs cut from the petrol smart’s €0.06 per km (6.3p per mile) to €0.02 per km (2.1p per mile).

The smart ev is claimed to be the only electric vehicle with two airbags, ESP, ABS, pre-tensioned seatbelts and a sturdy safety cell. Up to two hundred electric smart evs will be built by Zytek at its technical centre in Fradley, Staffordshire, for use in UK market trials. The vehicles will be leased to selected corporate customers from November.

Zytek’s new electric drivetrain for the car uses rare-earth magnet technology to deliver ‘exceptional’ power density and efficiency. The brushless DC motor (which can deliver up to 125Nm peak torque and 55kW (74bhp) peak power in other applications) is calibrated to produce 120Nm peak torque and 30kW (40bhp) peak power in a package that weighs 70kg including the motor, gearbox, inverter and control electronics.

The standard car’s cooling system is modified to control internal temperatures, using the existing front-mounted radiator with water flow assisted by an electric pump. The new drivetrain module interfaces with all existing vehicle systems including ABS and ESP.

Zytek believes that this is the only EV powertrain in production that delivers such a high level of integration with other vehicle systems.

Power is provided by a Zebra liquid sodium nickel chloride battery, mounted under the floor near the centre of the vehicle. Running at 180-310V it has a specific power density of 194W/kg, giving a range of up to 72 miles in a standard EUDC test. The high voltage charger, 12V charger, battery cooling fan and brake vacuum pump are installed on a purpose-designed ancillaries frame at the rear of the powertrain bay.

Because electric motors produce maximum torque throughout a large rev range a single ratio equivalent to second has been selected. To help maximise the driving range, the maximum speed is electronically limited to 70mph. With up to 50 percent more torque than the standard 50bhp petrol car, acceleration from low speeds is brisk.

To charge the vehicle’s battery from 30% to 80% capacity from a standard 13A socket takes two and a half hours. The battery is also charged by a regenerative braking system, which works with the ABS and ESP systems.

Zytek has worked with smart on a range of projects since 1998, but the integrated drivetrain fitted to the smart ev is the first to enter production from a range that will eventually provide vehicle manufacturers with power options from 30kW up to 100kW.