Press Release, September 3rd 2009

Engineering and Technology of the E3

E-car specific design, distinct drive train and grid integration by means of an integrative architecture

Designed and produced on behalf of the EWE AG in Oldenburg, the E3 is a real e-car. And at the same time the E3 is a regular A-segment passenger car, which is suitable for daily use and street-legal. It distinctly stands out from the crowd of comparable hybrid or conversion solutions. With regards to its technical maturity it is a fully functional preproduction model. It features an OEM-independent e-architecture and can be adjusted flexibly to different forms of grid integration.

Hands-on product specifications

The four-door hatchback sedan can dispose of four seperate seats and a full-fledged trunk capacity. The car has no noticable space limitations resulting from its drive train and battery. The traction battery is integrated into the car from underneath and thus fully integrated into the body in white. The range covered within the NEDC cycle amounts to around 200 km and in daily use to more than 150 km.

The electrical and electronical integration of the grid enable an „intelligent charging“ by means of future wireless communication of the power lines to the grid. The first delivered vehicle can be “super-charged” on 400V industrial electrical plugs.

The research objective of the so-called three phase feed-back and the bi-directionality of the power supply is achieved by an open CAN architecture. Mere passive loading can be performed at any time on all electrical plugs (230V/400V).

Original E-Car Design

In order to define the design of the car, special emphasis was given to the motto “e-mobility beyond limits”. Even from a distance, the design identifies the car as the EWE e-car. The connection of coordination and communication is highlighted by visual and functional elements in the light concept, the power supply and even by means of design and color. The transparent hood and the functional hatch with integrated power supply, are an eye catcher and provoke people´s curiousity.

The sporty e-car with its transparent surfaces does without visible seals in favor of a modern and smooth body. Distinct wheel wells boost this effect. The topic of electrical power is visualized by means of the circuit track and the PBC structure on daytime trips as well as in the dark and this clearly distinguishes the car from combustion engine cars. The light band makes a reference to the synapses of the electrical information flow in the human brain.

The cockpit is dominated by two electrical display- and communication instruments, which visualize the energy management. Also, this is where the driver can retrieve all relevant vehicle data. The button gear shifting can be found in the center console, which spreads out to the back seats. The back seats are furnished with two seperate standard size seats. All seats are upholstered with a newly developed fabric, which incorporates the exterior color into the interior of the car.

Distinct USP

The vehicle disposes of an energy-saving low-energy air conditioning, which uses the residual heat of the power components and realizes the requirements of the different operating points by means of a seperate air conditioning ECU. The battery was integrated into the body-in-white, which not only facilitates passive cooling by means of using the underbody air, but also allows for a fast battery change (for research purposes).

The pilot production power train components consist of a synchronous motor, which features a high level of effiency even in the partial load state and of a water-cooled inverter, which encompasses its own power-off system. The inverter can shut off its power regarding the different operating points, which means it is metered operating point- and profile related. That way the start performance amounts ot 57 kW and the maximum continuous rating is 37Kw. Furthermore a one-gear serial transmission has been customized to the E3, which already matches the target costs of the series production.

Using GSM, renders a complete remote diagnosis of all comfort- and power units is possible. Thus it can communicate with the internet and provide the driver with specific location information. The E3 project demonstrates that the network integration of hard- and software is given the same priority as the vehicle as such. That is what distinguishes the E3 from other E-cars, which merely focus on the battery-electric power train and yet neglect the communication aspect.

source: Karmann