Application AreaElectromobility

Electromobility

Electromobility is a reasonable solution addressing the challenges in the transport sector to reduce the oil dependency, carbon footprint, pollution and noise. The European Commission has agreed to reduce 60% greenhouse gases from transport and phase out conventionally fuelled vehicles from cities by 2050. In 2030, Sweden should have a vehicle fleet that is fossil fuel independant to reach the target of a net zero greenhouse gas emissions in 2050.

It is a great challenge to convert the necessary vehicles from fossil fuel propulsion and component operation to electric counterparts in order to meet the European and Swedish targets. Electric vehicles have different properties and should be handled differently. A successful end will only be achieved if proper technology developed is affordable and appreciated by the users. This means that a lot of knowledge is required about possible and upcoming technology, business models, user behaviours and expectations from society.

The overall aim of all activities in the Electromobility application area at Viktoria Swedich ICT is to increase the knowledge and contribute to the conversion of more electric kilometers in all type of transportation modes. Electromobility is not an established research discipline, but researchers from different disciplines with different knowledge and academia and industrial background will address the challenges together. Since people in the application area work closely together, the knowledge and experience can be spread to each other reducing the risk of inventing the wheel ineffectively over and over again.

The work performed in the area is quickly adapted to the changing environment and increasing knowledge. We are currently working with different applications, activities and fields of research; some of these areas are explained in the following and the project pages gives further information of current activities.

 

Energy Management and powertrain design
In general, energy management includes planning and operation of energy-related production and consumption units. The objectives are resource conservation, climate protection and cost savings, while ensuring users permanent access to the energy they need. From a control point of view, energy management is how to select the specific control settings among several possibilities. In vehicles, the phrasing usually refers to the case when there is access to several energy sources that can propel the vehicle like in hybrid powertrain  (e.g. a diesel engine and an electric machine in some type of powertrain configuration) or when the excess energy can be stored in several buffers (battery, super capacitors, flywheels etc.). However, there is also an increased interest to use energy consuming systems (e.g. climate system and other auxiliaries) in a better way, which also ends up in an energy management problem. A cost efficient way to tackle energy management problems is by using methods like modeling, optimization and simulations; tools that are well used in the control engineering research discipline.

The design and study of a suitable powertrain configuration and included component sizing is handled well using the same methods as for the energy management problem, namely modeling, optimization and simulations. When designing a hybrid powertrain, an energy management system has to be included as well. A reasonable way to tackle this problem is to do the energy management in the same way always, using optimization techniques. In this way, the different powertrain configurations can be fairly compared and do not depend on the different energy management solutions. To end up in optimal fuel consumption, or close to it, it is important to use predictive information. This connects the energy management area to infrastructure related questions and the sharing of (open) information, issues that are also of interest for Viktoria.

Both energy management and powertrain design problems end up in optimization problems that are hard to solve (coptimal steering of nonlinear dynamic models). The standard solution is dynamic programming, which means that the time and states are gridded into small pieces, and then all control possibilities are searched by massive calculations. However, by suitable approximations and proper formulations, the problem can be set up into a convex optimization problem which is good since it essentially speeds up the computational burden, making it possible to run the resulting algorithm in real-time in the vehicle´s intended control system  processor.

The energy management that is performed in Viktoria is highly appreciated. Theory is developed closely together with Chalmers University of Technology and the methods are applied together with the Volvo companies. Henrik Svenningstorp, Director Alternative Vehicle Efficiency at Volvo GTT ATR Energy Efficiency & Environment, says “The research on methods and software tools for hybrid vehicle energy management at Signals and Systems Chalmers and Viktoria Swedish ICT strengthens AB Volvo’s on-going projects and provides a good example for fruitful collaboration between industry and academia.” An interview with Professor Cristofer Onder at ETH in Zürich around energy management can be found here.

 

Charging infrastructure - deployment and ICT issues
There must be charging infrastructure to provide electric vehicles with energy. To many, this is seen as a chicken and the egg problem, that is no electric vehicles, no infrastructure and vice versa. There is also standardization issues related to the development; a lack of standard prevents investments to be made. European Commission tried to address this problem by issuing a proposal for a new Directive on the Deployment of Alternative Fuels Infrastructure to guide the harmonized development of charging infrastructure for EVs at a Pan-European level. Member States will be faced with the challenge to set up both a policy framework and the required public charging infrastructure for electric vehicles.

Many stakeholders propose solutions that are beneficial for their own business. However, unless the introduction of a charging infrastructure is done with care, the user perspective and overall economy and costs in mind, additional costs will add expenses to electric vehicles, which does not lead to a positive increase of electric vehicles.

A dividing line with high economical and technical consequences is whether the charging point should be connected to the digital infrastructure (the cloud) or not. Instead the charging points, the vehicle could be connected. There are no additional costs connecting vehicles, since automated emergency call for road accidents will be mandatory in cars from 2015 within the European Union.  Sweden already has an existing electric infrastructure in the form of garage outlets and motor heaters. It is most likely much cheaper to use these (possible retrofitted) for vehicle charging and possibly make them publicly available.

The infrastructure should be built where charging with and without cables are possible, and for stationary and moving vehicles. From this perspective, it is reasonable to put electric meters in electric vehicles to measure the energy and base costs on the consumption. Future vehicle electricity taxes can then easily be calculated.

 

Inductive charging
Electric vehicles need to be charged. Plug-in electric vehicles need not to be charged since they can be run on alternative fossil fuel, but the higher investment cost cannot be motivated unless electric charging is done often and when possible. Furthermore, from a grid perspective, electric vehicles need to be connected to the grid whenever possible to make it possible for the utility companies to charge the vehicle at times when there is sufficient energy available. Otherwise, there is a risk that everyone only charges at peak-times, which will be costly for everyone in the end.

There are indications that people that drive electric vehicles after a while only connects the vehicle and charges it up when needed. Furthermore, plug-in users tend to charge their vehicles less and less by electricity. The reason for this is that it is not convenient to connect the cable to get a small amount of energy. What is possibly required is that the vehicles should be connected and charged automatically without the interference with the users. One solution making this a reality is inductive charging, i.e. the energy is transferred wireless by electromagnetic fields. Using magnetic resonance, the efficiency can be as high as 90-95% through the air gap between the primary coil in the ground and the secondary coil in the vehicle.

One of the challenges in doing inductive charging equipment is to have control of the magnetic leakage fields, in order to maintain efficiency and prevent magnetic fields to be of risk for humans and animals. The frequency that is decided is 85 kHz, but since we have not been exposed for fields in the kHz  range before the biological impact is unknown. This is an important area where knowledge should be increased.

Today there are several manufacturers making inductive charging equipment, like Qualcomm, Witricity, Plugless Power etc. Currently, these try to join with different vehicle manufacturers to propose convenient solutions. Combining inductive charging with smart charging and payment gives users an automatic convenient system that takes care of itself.

 

Electrified Road Systems
Heavy-duty transport driving long distances cannot be propelled by electric energy coming from batteries, since the whole cargo space would have to be filled with them. The railway system in Sweden has reached its capacity limit and there is not much room for transferring goods transported by trucks to trains. Other solutions need to be innovated. Electrified Road Systems (or shortly electrified roads) refer to the application where electricity is continuously transferred from the road to the vehicles while driving. Covering the highways and larger roads in Sweden by electrified roads means that vehicles can cover long distances on electricity, essentially reducing the carbon dioxide emissions. Including a battery allows the vehicle to still drive on electricity in e.g. crossings where it is complicated to build the electricity transfer lines, or to shorter destinations between the electrified roads.

Electrified road systems can be achieved in different ways, e.g. from above with wires, or below using either conductive (contact transfer) or inductive techniques (wireless transfer) which all have their pros and cons. The advantage of having it from above is (probably) a simpler technical solution and cheaper investments. However, the main drawback is that passenger cars cannot utilize the electric wires since they are too high up. Furthermore, the wires require poles, which might hinder accessibility (helicopters use the space besides the highways for landing in case of emergency), and changes the appearance of the highway. These drawbacks are arguments for taking up the energy from below. However, this means engaging in the road and pose potential safety risk both in form of electrocution and accidents due to level differences between the rail and the rest of the road. The latter can be avoided by inductive solutions, but this is probably more expensive than using conductive energy transfer.

There is still an open discussion in Sweden on which technology should be used for electrified roads. In the end, a lot of money is needed to build electrified roads and different stakeholders argue for their solution. Sweden cannot of course develop own solutions; we need to have a common solution for at least the entire Europe. Therefore, standardization will be an essential part before a solution is decided upon.

Building electrified roads involves everything from road construction, energy supply, vehicle electrification and pick-up, economy, business models, safety aspects etc. A successful story will only be possible if different actors and competences work together to build knowledge.

 

System architecture and systems engineering
According to the definition from IEEE, system architecture is about the components contained in the system, the relationship between the components, and the principles guiding the design and evolution of the components. In addition, systems engineering focuses on how to design and manage complex systems throughout their life cycles. As such, system architecture and systems engineering are enablers for Electromobility on all levels; for integrating additional components like electrical motors in existing powertrains to create hybrid powertrains, for integrating hybrid or pure electric powertrains in already complex vehicles, for design of charging infrastructure and energy transfer solutions, etc.

In a similar way, system architecture and systems engineering are enablers for other automotive functional domains such as active safety, autonomous vehicles, infotainment, and HMI. The system architecture is viewed as a platform for innovation in increasingly open communities.

Viktoria has activities going on in several disciplines connected to system architecture and systems engineering; modeling & simulation (Second Road), development processes and tools (Vehicle ICT Arena), etc. We also have competence from earlier projects in system architecture analysis and optimization, reference architectures, and software defect classification and analysis. We are familiar with relevant standards and technologies used in the automotive and transport sectors.

 

Components like batteries and fuel cells
Batteries are essential components in electric vehicles. To give users confidence, it is important to estimate the remaining range based on estimations of the energy content of the battery. For hybrid vehicles, inaccurate estimations of e.g. State of Charge (SoC) may potentially lead to higher fuel consumption. SoC is equivalent to the fuel gage of a battery pack, an aggregated state that cannot be measured directly. Other important properties of batteries are how much power can charge/discharge, which is captured in a variable denoted State of Power (SoP), and the health of the battery, denoted State of Health (SoH), indicating the degradation after long time usage.

The requirement on the accuracy of SoC, SoP and SoH should be based on high-level requirements on accuracy for e.g. range for electric vehicles and fuel consumption for hybrid vehicles. At Viktoria, there are projects a around this and methods how to estimate the different properties using filtering techniques (like extended Kalman filter, adaptive methods etc.). New methods how directly measure SoC is currently under investigation.

Different car manufacturers claim Fuel Cell vehicles will be available for purchase in a few years. Viktoria employees have followed for a long time the development of the Fuel Cell market, specifically on what is happening in Japan and Korea. Furthermore, Viktoria also has competence on the low level regarding proper materials in fuel cells.

 

Electromobility Showcasing

Electric vehicles come in different shapes and sizes, ranging from simple electric two wheelers to luxury sedans and even electric ferries. The mobility services they can provide users with also vary accordingly.

It is important that the functionality of electric vehicles cease to be judged based on their internal combustion counterparts, instead they should be judged independently, by the different and innovative mobility services they can provide. Some early adopters are willing to try new disruptive technologies such as electric vehicles. However, the best way to help the general public familiarize themselves with electric drive is to have demonstrations areas that can allow them to try this technology without having to engage in the costs and risks of ownership.

Viktoria is putting efforts in developing demonstration hubs that bring together different forms of electric vehicles and mobility services. Such hubs can have for example, market-trendy Electric Bikes (E-bikes), which reduce rider’s efforts by assisted electric pedalling. This means the same accessibility and route liberty of regular cycles, while removing the barriers to cycle because of physical efforts. Another option is free-floating electric car-pools, which give users access to an EV closest to them and allow them to leave the car at any place of their convenience. Finally, electric taxis will allow users to make door-to-door travel, while significantly reducing the local pollution of taxi fleets. All vehicle options should be integrated and made available to the general public in a way that helps them select the most time, cost and environmentally efficient option that meets their changing mobility needs for each individual trip; no more having to worry about one-way trips or feeling guilty for needing to use a car.

Demonstration hubs are important not only for public awareness of electric vehicles, but also to gain empirical knowledge on user behaviour and real life technology performance - hence, as a research institute, we see the demonstration hubs as research platforms. Viktoria aims to apply this knowledge for technology improvement and business development for electromobility.

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Darijan Jelica
Researcher
+46 76 364 63 66
darijan.jelica [at] ri.se

Patrik Klintbom

+46 72 250 62 44
patrik.klintbom [at] ri.se

Ana Magazinius
Senior Researcher
+46 73 654 54 05
ana.magazinius [at] ri.se

Niklas Mellegård
Senior Researcher
+46 73 996 53 39
niklas.mellegard [at] ri.se

Ella Rebalski
Researcher
+46 76 108 30 75
ella.rebalski [at] ri.se

Arwed Schmidt
Senior Researcher

arwed.schmidt [at] ri.se

Håkan Sundelin
Senior Researcher
+46 73 027 84 93
hakan.sundelin [at] ri.se