SinusLeistungsSteller - e-Velomobil 06.19.2009


QUEST - electromotive velomobile from Wulf Kraneis ...

... a possible way to travel away from "Peak-Oil", which also keeps fit!




Introduction from Wulf Kraneis:

On the basis of the successfully in series produced streamlined velomobile from Velomobiel.nl (three wheeled recumbent bike) an electromotive vehicle was produced, which (with electrical support of 250W) enables well trained cyclists a traveling speed of 60-65 km/h on the plane and hillup up to 45 km/h.
The inbuilt technology would allow even more stunning performance: 95-100 km/h on the plane and 60 km/h at 5% slope. This can be traced back in general by the excellent aerodynamics, which was further improved compared to the basic model. Slopes of 15% or more are of course no problem, but it should not be concealed that, in plane the basic model can achieve with pure "human power" a permanent speed of 45-50km/h.

The goal during the development of the vehicle was a possible constant speed of about 70-75km/h on the plane (disregarding the legal acceptance) of simultanously low energy consumption, which should amount to max. 10% of a in series produced car with very low fuel consumption and is also due to the fact, that the driver always actively supports the movement and so experiences the movement completely different than compared to a car.

The velo is designed in a way, that without the drivers support the electro-motor by pedaling the vehicle does not move. On slopes of 5% a speed of about 50km/h should be always possible, in order to prevent the average travel speed from decreasing significantly. Also important the additional weight (at a base weight of ca. 32kg) has to be under 10kg for a distance of about 150km (which is possible).

This also ensures, that the vehicle would not constitute a traffic obstacle either in the city or on country roads, which would be a key point for a successful attendance on the road. Also travel time would not (or only insignificantly) be increased, compared to car travel up to 50 km.


The Implementation:

After a first analysis, some discussion and some preliminary tests with possible components that were attached to an ergometer, we recommended in addition to our SLS-42-110 controller also a suitable motor from Torcman.
This is coupled via an additional free wheel and a reduction gear through the crank drive to the drive chain. This ensures that the motor can only support, when the cranks rotate. We can set the max RPM of the motor via SLS-42-110 parameter and determine very precisely up to which max. speed electrical support is added to the "human power". A second positive effect in terms of human powered support: the startup is only possible with human power, because the currently available SLS is not able to start the motor with full torque from standstill.

The battery was built by Wulf Kraneis of 12 parallel strings, each with 10 in series (10S12P) connected lithium-ion cylindrical cells, this resulted in length formed battery packs, which can be put in the velo very easily. With about 7kg of weight the weight adder is very modest. The target point is set by our Sollwertgeber (SG), the (SG) potentiometer (can be used with the thumb) is directly attached to the steering wheel.

We met on the 19.06.2009 in Kist to install the SLS into the prepared vehicle and performed first driving tests, in order to tune the controller.



The first slow rounds have been completed in speed control mode, but after we switched to torque control mode, Wulf Kraneis did not want to miss it ... ;-)



Step by step we increased the power of the motor and optimized the last parameter under load. In between, you felt almost like in a F1 box while practising ;-)



All in all the velo covered today a test distance of 35km in very hilly terrain with a average speed of about 50km/h. Consumed for that were less than 0,25kWh of 1,0kWh energy contained in the battery. If you add up, a considerable distance of about 150km per kWh results! How much human power was contributed, only the driver knows. To us he did not appear exhausted - he was quite the opposite!



Again: distance 150km/kWh!!! If you would convert a liter of diesel (energy content of 10kWh) by diesel engine and generator into electrical energy (we take a relatively modest efficiency of 35%!) we would get 3.5 kWh of electrical energy. The velo could drive with that over 500km! That is about 5 times as far as the most efficient car automotive industry has ever produced (and that only for test purposes!) and about 40 times as far as an average car today!