Yearly Archives: 2014
Friday, October 31, 2014

Five questions for Rasmus Andersson

Rasmus Andersson will soon present his licentiate thesis, entitled ”Electric Traction Machine Design for Heavy Hybrid Vehicles” at Lund University.

Read the interview on the Swedish page.

Rasmus AnderssonTitle: Electric Traction Machine Design for Heavy Hybrid Vehicles

Time: 12 november 2014 kl 13.00

Location: Lund University, M:B, M-huset, Ole Römers väg 1, Lund

Discussion leader: Prof. Yujing Liu, Chalmers tekniska högskola

Supervisor: Prof. Mats Alaküla, Avd för industriell elektroteknik och automation, Lunds tekniska högskola

Ass. supervisors: Dr Avo Reinap, Avd för industriell elektroteknikoch automation, Lunds tekniska högskola; Dr Anders Hedman, Volvo GTT

The research project Hybrid drives design for heavy vehicles is part of the Swedish Hybrid Vehicle Centre (SHC).

Read more about the project >>

Monday, October 6, 2014

Customized propulsion systems may lead to cheaper electric cars


You and your neighbor drive the same car model, but the car’s propulsion system is tailored to your needs, and you only pay for a battery of the size that you need for your daily driving. If you change your driving habits, you replace the battery but keep the car. This may be the future for electric vehicles with range extenders.

Jonas Sjöberg and Victor Judez are active within SHC and work at the department of Signals and systems, Chalmers.

For most electric cars a small battery will suffice for everyday use, but for the occasional longer journeys the power supply will not last all the way. On these occasions, a small internal combustion engine, often called a range extender, can act as a generator for the battery. This way you can drive electrically for most of the time, while extending the car’s actual range. The technology is applied i.e. in the BMW i3.

Researchers Jonas Sjöberg and Victor Judez from Chalmers have, together with Anders Grauers and Nikolce Murgovski, developed methods for dimensioning the battery size for different vehicle categories and driver types. The researchers have based their studies on driving habits, taking into account assumptions of how often the battery can be charged and other influencing factors. The work has been conducted within a research project, OPTIMORE, with participants from five EU countries.

– Using our results, vehicle manufacturers can find out which battery sizes they should offer to their customers, and how large the assortment should be, says Jonas Sjöberg, Professor of Mechatronics, who has led the study. In the future, one would imagine that the same car model is offered with different propulsion concepts. Car buyers could get a tailored combination of battery and range extender and would not have to pay for a larger battery than needed for everyday use.

Logged driving routes is one of the influencing factors considered in the study. A car driving an unfamiliar route will deplete the battery first, and then utilize the internal combustion engine. If the car has prior knowledge of the route, the battery use can be spread over the entire journey, so that the car can get by with a smaller range extender.

– Considering the different concepts that can be developed, I believe that the battery will soon not be considered a static part of the car, but as a module that can be re-built  into a larger or smaller battery when you change your driving habits, says Jonas Sjöberg.

Project partners Volvo Cars, AVL and IVECO have manufactured prototypes to explore the practical challenges of the technique. Top: The range extender of Volvo’s all-round vehicle has been tested by researchers from the Department of Applied Mechanics, Chalmers. Above: The city car prototype from AVL. Photo: ©FP7 project OPTIMORE

About the project
OPTIMORE (Optimized Modular Range Extender for every day customer usage) is an EU-funded project in FP7, aiming to reduce energy consumption, emissions, cost and noise levels of ER-cars and extend battery lifetime. The project is associated to activities within SHCS, and is a continuation of the project Fuerex which was initiated by SHC.

Project partners
AVL Schrick
Centro Ricerche FIAT
Chalmers University of Technology, departments of  Signals and systems and Applied mechanics
GETRAG Corporate Group
Volvo Car Corporation

Text: Emilia Lundgren

Wednesday, October 1, 2014

48v-system och laddinfrastruktur på höstens FFI Electromobility workshops

This text is only published in Swedish.

Thursday, August 28, 2014

Dialogue necessary for the design of cost effective electric machines

The present development processes of electric and hybrid electric road vehicles allow little room for dialogue between the powertrain designer and the designer of the electric machine. As a consequence, the specifications for the electric machines lack the information needed to develop truly cost effective vehicles. This calls for a new way of discussing specifications and requirements, say researchers from SHC and Chalmers.

Karthik Upendra and Anders Grauers, SHC / Chalmers.
We need new ways of discussing specifications and requirements for electric machines, say Karthik Upendra and Anders Grauers from SHC/Chalmers.

One of the challenges for the electric and hybrid vehicle industry is the difficulty to describe the thermal limits of the electric machine in a short and simple way, which makes it hard to determine exactly how an electric machine can be used and when it will reach its temperature limits. This can lead to either under-sizing of the machine – possibly causing a breakdown – or a systematic over-sizing, leading to higher costs and increased weight of the machine.

– The development of new technology cannot rely on old knowledge, but requires a direct dialogue in order to find improvements, says Anders Grauers, hybrid vehicle specialist at SHC and researcher at the department of Signals and systems, Chalmers. Along with Karthik Upendra he has studied the key challenges regarding requirements and specifications of electric machines for hybrid and electric vehicles.

–We need to find a new way of discussing these requirements, across the different sections of the chain of development, Anders Grauers continues.

The researchers initiated a discussion between experts from different parts of the field. They found that the specifications used today do not provide the designer of the electric machine with adequate information, nor do they meet the needs from the vehicle industry. According to Anders Grauers, the problem can only be solved by a dialogue between powertrain designers and electric machine designers, in order to identify requirements with a good balance between electric machine cost and vehicle performance.

–In an initial dialogue, we should look for simple models to be used as “thinking tools”, says Anders Grauers. Of course complex models are essential, but if they are hard to understand by experts with very different background, they may prevent effective interchange.

In the project report, the researchers analyse the basic requirements on an electric motor in a road vehicle, using a very simple thermal model, and identify some of the driving scenarios that could be critical for the thermal design. Anders Grauers hopes that the report can be used as a starting point for discussions between powertrain designers and electric machine designers on the most cost effective ways of handling the thermal limits.

– Our work highlights a topic where we have little knowledge today, and gives ideas on how to explore it further, he concludes.

Text and photo: Emilia Lundgren

The project Cost effective electric machine requirements for HEV and EV is part of the Swedish Hybrid Vehicle Centre (SHC).

Anders Grauers, Vehicle analysis group, SHC
Chalmers University of Technology
Department of Signals and systems

Karthik Upendra, MSC automotive engineering
Chalmers University of Technology
Department of Signals and systems

Learn more:
Workshop summary >>
Workshop presentation >>
Project report >>
Project webpage >>

Monday, June 2, 2014

New Swedish record for KTH students in Shell Eco-marathon

Student teams from around the world meet every year at the Shell Eco-marathon to design, build and test energy efficient vehicles. The winners are the teams that manage to design vehicles with the lowest energy consumption. This year’s competition was held recently in Rotterdam.

The electric car Elba from KTH reached fifth place in the category of Urban Concept – Battery electricity. Like last year, Elba managed to make a new Swedish record.

– Elba made 181.5 km/kWh, says project leader Mikael Hellgren at KTH Transport lab. This is equivalent to going 180 kilometers to the cost of 0.11 Euro. But the journey would of course take a few hours, he adds, since the speed is 25 km/h.

Elba was built and raced for the first time in 2013. This year the car has been fitted with solar panels and a new control system. To increase the complexity factor, the race rules also required that the inverter for the electric motor would be built by the contestants themselves. Previously, ready-made inverters and motors have been accepted.

– There is a growing interest among students to participate in the Eco-marathon, says Mikael Hellgren. In fact, the number of team members in 2014 was bigger than ever before.

KTH also competed with the fuel cell prototype Sleipner. As in previous years, SHC was among the sponsors of the teams from KTH and Chalmers.

Read more on the students’ blog >>

Text: Emilia Lundgren