|The 55kW E-Drive fits neatly onto the existing engine mounting points with just three additional connections (water, high voltage electrics and low voltage electrics). Click to enlarge.|
Zytek has unveiled a fully engineered, electric version of the Mercedes A-Class that it developed in just ten weeks. Designed to demonstrate the capability of the company’s production-ready 55kW E-Drive electric powertrain, the five-seat electric family car project is a Zytek in-house activity and is entirely independent of Mercedes-Benz.
For the A-Class demonstrator, Zytek developed an uprated version of its 55kW E-Drive, using a higher current switching system to increase the maximum torque from 120N·m (89 lb-ft) to 160N·m (118 lb-ft). Zytek also increased the maximum motor speed from 12,000rpm to 13,000rpm to provide a top speed of 70 mph (113 km/h) while providing sufficient torque to ensure good low speed performance and the ability to comfortably climb steep gradients.
|The electric A-Class demonstrator. Click to enlarge.|
The A class application provides ‘plug-and-play’ functionality, with the motor, inverter and control electronics integrated into a single unit. The complete assembly fits neatly onto the existing engine mounting points with just three additional connections (water, high voltage electrics and low voltage electrics) and will interface with all existing vehicle systems including ABS (Antilock Braking System), ESP (Electronic Stability Program) and OBD (onboard diagnostics).
Power is provided by two air-cooled sodium nickel chloride battery packs, integrated under the floor of the vehicle so they don’t compromise luggage space or vehicle stability. Range is expected to exceed 120 miles (193 km) in a typical mixed drive cycle and the level of regenerative braking can be easily calibrated to match customer requirements for driveability and refinement.
Performance of the Zytek electric A-Class is brisk, even though the power output is electronically limited to 40kW to increase battery life. “The rated power doesn’t sound much, but comparisons with conventional engines are irrelevant because of the completely different torque characteristics,” highlights program manager Neil Cheeseman.
Taking a vehicle like this into manufacture would be relatively simple, says Zytek Automotive sales and marketing director Steve Tremble. “The E-Drive has been designed with homologation in mind, and the modular nature of the unit, with the small number of fixings, means that it can be simply installed on the production line alongside conventional power units. We are already managing this process for one premium manufacturer.”
Zytek’s range of integrated electric drive modules allows the rapid development and cost-effective manufacture of electric derivatives for a wide range of cars and commercial vehicles up to 5.5 tonnes. Current production applications for E-Drive, which is available in high power density 55kW and 70kW versions, range from the smart fourtwo electric city car, through a number of C- segment family saloons and light duty vans, to several categories of heavier commercial vehicle.
Low-volume vehicle build, typically for fleet trials, is conducted at Zytek, while for higher volumes the company supports assembly at the customer’s vehicle manufacturing facility, with the highly integrated design of E-Drive making it suited for integration alongside standard models.
Zytek has designed and integrated electric drive systems for a wide range of European and US vehicle manufacturers and is currently building high performance electric drivetrains up to 70kW (94 hp) and 300N·m (221 lb-ft) for cars, busses and light commercial vehicles. Their UK facility can accommodate up to 6,000 E-Drive integrations a year in batches as low as 100, providing vehicle manufacturers with a flexible specialist production resource for their low carbon programs.
Although the design and build of the A-Class demonstrator is an entirely Zytek activity, the company has worked with Mercedes on a range of projects over more than a decade. Most recently, Zytek managed the design and build of 100 first generation smart ed electric vehicles and is now working with smart on a production version of the second generation vehicle. As a supplier of engine management systems for internal combustion engines, Zytek is also can deliver hybrid vehicle programs and has already worked on a number of vehicles, including two diesel applications.