TU/e introduces converted VW Lupo electric research vehicle; lightweight and longer range
09 April 2011
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| The donor Lupo, the old diesel powertrain, and the new electric powertrain. Click to enlarge. |
Over the past year the Dynamics and Control group of the Eindhoven University of Technology (TU/e) (The Netherlands) has developed a battery electric research vehicle based on a VW Lupo 3L 1.2 TDI. The vehicle, formally launched this week, will be on display at AutoRAI in Amsterdam, 13-23 April.
The Lupo EL (“Electric Lightweight”)vehicle combines a very low weight (1,060 kg, 2,337 lbs) with a large battery pack (27 kWh). This results in a range increase of 30% to 50% in comparison to existing electric vehicles with four seats on the market today— 215 km (134 miles) urban and 135 km (84 miles) highway on the Artemis cycle. Despite the presence of a large battery, the interior and cargo space dimensions remain unchanged.
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| Electric vehicle system diagram. Source: TU/e. Click to enlarge. |
The 4-seat Lupo EL has a top speed of 130 km/h (81 mph) and accelerates from 0 – 100 km/h in 12 seconds.
The Thundersky batteries use a lithium iron phosphate (LiFePO4) chemistry, which has a comparatively low cost of less than €300/kWh (US$434/kWh), is considered safe and has a long cycle life. The disadvantage is somewhat reduced energy density compared other Li-ion chemistries.
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| Under the hoods of the Lupo TDI and Lupo EL. Click to enlarge. |
The vehicle is approved by the Dutch roadworthiness authorities (RDW) and is allowed to drive on the public road. The vehicle is developed for research purposes and includes various sensors to monitor the batteries, power train, energy consumption of components and vehicle dynamics. Furthermore, the vehicle is equipped with a central controller (PLC), which controls 4 CAN busses and 80 I/O ports. This results in a very flexible, programmable environment allowing different types of research to be executed. Additionally the existing VW systems, including ABS, airbags and dashboard are fully functional.
Various research topics have been and are being addressed, including:
- vehicle performance analysis, range estimation and battery sizing;
- efficient heating of the vehicle interior;
- component testing and modelling, e.g. battery efficiency;
- analysis of regenerative braking strategies;
- full vehicle modelling using multi-body software tools;
- investigation of the benefits of in-wheel motors;
- vehicle control software development;
- development of a user interface to inform the driver on the vehicle status; and
- electric power steering.
Power train components include:
Charger: Brusa NLG 513 WC, charging power 3.3 kW, 260 - 520 V DC out, programmable, water cooled, CAN
Charging plug: Mennekes 31013, VDE-AR-E 2623-2-2
Li-ion batteries: Winston Battery/Thunder Sky TS-LFP90AHA, capacity 90 Ah, 3.3V, cycle life > 2000 @ 80% DOD, chemistry: LiFePO4, 91 cells in series, 273 kg, 27 kWh
BMS: Elithion Lithiumate, measurement of cell voltage, temperature and internal resistance, passive balancing, max. balancing current 200 mA, CAN
Inverter: MES-DEA TIM 600W, max. current 236 A (nominal), 400 A (peak), 80 - 400 V DC in, switching frequency 3-9 kHz, water cooled, CAN
Motor: MES-DEA A200-200, 24 kW/80 N·m (nominal), 50 kW/270 N·m (peak), AC induction, 10500 rpm max., water cooled
Reduction: Carraro 150009, single gear fixed reduction, ratio 8.654:1
DC-DC converter: MES-DEA 400-1000 150 - 400 V DC in, 13.3 - 14.4 V DC out, max. power 1000 W, max. current 70 A, air cooled
PLC: IFM CR0232, 32-bit CPU Infineon TriCore 1796, 80 IO ports, 4x CAN
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| Range and energy usage. Click to enlarge. |
The motor description seems to be for a single motor, but they say that they are testing in-wheel.
Can anybody throw any light on this?
Posted by: Davemart | 09 April 2011 at 07:21 AM
In the picture you can see it's a single MES motor bolted to the Carraro gear reduction box. You can buy all these components yourself from metricmind.com, but they are very pricey.
Posted by: JRP3 | 09 April 2011 at 08:34 AM
135km range ont he highway? Mmmm...that might be enough to get me to Whistler for the weekend IF it wasn't uphill all the way.
Posted by: ai_vin | 09 April 2011 at 10:11 AM
This looks like the conversions people did in their garages 30 years ago. They had maybe 50 mile range and not 100, they had brush D.C. motors instead of 3 phase, but they did similar things in a suburban setting.
Posted by: SJC | 10 April 2011 at 09:16 AM
Right car, wrong battery (only 100 Wh/kg).
Posted by: clett | 11 April 2011 at 01:37 AM
Also, a GM Volt manages similar (if not better) miles per kWh, despite weighing almost twice as much.
Posted by: clett | 11 April 2011 at 05:56 AM
Clett,
How do you derive that from the figures in this article? 27 kWh nominal capacity @ 80% DOD = 21 kWh usable for 135 km. That works out at 15.5 kWh/100 km. Is that worse than the Volt? The epa test is 22.5 kWh/100 km. How does the Artemis test compare to the EPA? Too many unknowns.
Posted by: Arne | 11 April 2011 at 06:56 AM
I worked it out as the real-life range the Volt owners are reporting on their forums (www.gm-volt.com), which is about 40 - 45 miles per charge for 10.5 kWh at the battery. That's about 4 miles per kWh, or 15.6 kWh/100 km - similar to the highway cycle for the Lupo conversion.
More telling though is the chart on the right showing that the Lupo uses ~16 kWh per 100 km at constant 100 km/h. That suggests this tiny car requires 16 kW (or 21 hp) to maintain 60 mph. Admittedly, that's including charger losses, but even so it's nowhere near as efficient as the low weight and Cd suggest should be possible.
Posted by: clett | 11 April 2011 at 08:52 AM
Sim Drive, a spin off of Keio University (in Japan) has developed a 4-passenger e-car (the SIM-LEI) that will do 333 Km with a 24.5 Kwh battery pack. This car accelerates to 100 Kph in 4.8 seconds and has a top speed of 150 Kph.
They also claimed that it will do 10+ Km per Kwh (or only 10 Kwh/100 Km) in normal heavy foot use.
That seems to be much more efficient than the e-car mentioned above.
Posted by: HarveyD | 11 April 2011 at 09:59 AM
This says to me that the Thundersky batteries are not quite as efficient in/out. If you measure kWh at the plug versus miles per kWh, I would expect better than the Volt. This is under 2400 pounds and the Volt is almost 3800 pounds. I would expect the 4 miles per kWh to be more like 5.
Posted by: SJC | 11 April 2011 at 01:42 PM
SJC:
I don't know if you can read across makes and efficiency cycles like that.
The Artemis cycle seems to include a rural cycle as well as the more usual urban and rural, so how it compares it is difficult to say without really intense research.
Posted by: Davemart | 11 April 2011 at 02:02 PM
Fair point, which points out the need for comparison standards.
Posted by: SJC | 12 April 2011 at 07:53 PM
To experience MES DEA support : -
On AEVA's site see their Forum for - TIM600 Explosion at the Technical and Conversion discussion.
Posted by: T2 | 24 April 2011 at 03:56 PM