Building on the knowledge gained from more than 15 years of niche EV design, manufacture and operation, this new third generation unit is a clean-sheet-of-paper design that will significantly simplify the introduction of next-generation electric vehicles, from niche models to high-volume global programs.
The turn-key package is extremely compact and in air-cooled configuration is up to 45 percent lighter than today’s production EV powertrains. Even the water cooled version, suitable for demanding drive cycles, is up to 30 percent lighter. Available in sizes from 25kW, the highly integrated modular system can be configured for a wide range of vehicle sizes, applications and architectures.
At the heart of the powertrain is Zytek’s new, high efficiency permanent magnet synchronous motor. The high maximum machine speed of 14,000 rpm has enabled generated torque and hence machine size to be reduced considerably, bringing further reductions in cost and weight. When used in conjunction with the Zytek Electric Vehicle Control Module, torque delivery is scheduled in a way that further improves overall efficiency, whilst also eliminating the harshness that can occur during changes in torque demand.
Parallel design and integration of the major subsystems has allowed a high level of optimization. An example is the integration of the charger within the inverter, reducing the number of separate enclosures and connectors required in the vehicle, reducing cost and increasing reliability.
A new transmission, designed specifically for use with the new electric machine, is being developed by transmission specialist Vocis.
The compact dimensions of the new drivetrain make mechanical integration with the vehicle much simpler. The main connections required are High Voltage (to the traction battery) and Low Voltage (for electrical interface with the vehicle). The air cooling option brings a further substantial contribution to reducing weight and complexity by potentially eliminating the entire water cooling system.
The Zytek electric vehicle control module interfaces with all standard vehicle systems such as ABS (Antilock Braking System) and ESP (Electronic Stability Programme). It also provides the complete range of expected diagnostic information as well as its own range of diagnostic codes.
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 70 kW and 300 N·m for cars, buses 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 and large fleets with a highly flexible specialist production resource for their low carbon programs. Zytek can also manufacture up to around 18,000 high efficiency electric traction motors each year, with the option of integrated control systems to further improve overall system weight and packaging.
The design and build of 100 first generation smart ed electric vehicles was managed by Zytek, including support for fleet trials, and the company is now working with smart to manufacture the second generation electric vehicle at ‘smartville’ in Hambach, France.
In October 2009, Zytek was selected to provide a highly integrated 70 kW powertrain to a new joint venture company being established by US truck supplier Navistar and British electric commercial vehicle specialist Modec.[wzslider height=”400″ lightbox=”true”]