Abstract

 

eDAS is an acronym for efficiency powered by smart Design meaningful Architecture connected Systems. It's a specific targeted research project (STREP), funded by the European Union. eDAS is part of the ICT Green Cars 2013 theme for research and development, implementing the Seventh Framework Programme of the European Union for research, technological development and demonstration activities.

 

Holistic Energy Management for 3rd and 4th Generation of Electric Vehicles

 

Modern societies are eagerly looking for the integration of mobility into their urban living area and for reliable and safe electrical vehicle (EV) transportation, better efficiency and cost, comfort and low emissions for the environment. The trends are obvious, however, providing a hybrid/electrical car is only one part of the full picture. The “standard” customer is still very reluctant to buy a full electrical vehicle (FEV). The reasons are manifold but the most important is unpredictable mileage and limited autonomy. The prediction of the cruising range without any restrictions in terms of safety and comfort is a key point: essential is D-P-C (Drive safely, Park easily and Charge conveniently).

Today a nominal 100km range might vary from 50 to 130km in reality, depending on various conditions such as temperature and profile of the route. Increasing the capacity of the battery is no viable option because it results in a drastically increase in cost and weight of the car. Through eDAS we will limit the negative impact of high and low environment temperatures from -50% today to a maximum of -20% of the reachable range in electric vehicles, which corresponds to an improvement of 60% compared to state of the art. We will bring the subsystems of the EV to the optimum operating temperature range for faster “fast charging”, pre -conditioned passenger compartment and battery, also safety and convenience features, such as de-iced windows during winter time, based on the available subsystems without adding cost and weight. We will develop new designs and architectures combining battery, e-motor, electronics, charger and energy management.

Addressing this challenge of the architecture of all subsystems of the complete EV requires a wide area of expertise, and in consequence leads to a large consortium. For a list of all partners of eDAS, take a look on our partner's site. eDAS cooperates with the research projects iCompose and Incobat.

 

Objectives

 

To develop and demonstrate the innovative hardware and software solutions, including new materials, adequate resources and budget are required. eDAS will deliver following innovative demonstrators:

  • Smart battery system with thermal management and peak temperature conditioning based on novel materials such as phase change materials (PCM)
  • Novel e-motor with improved power density properties allowing reuse of thermal energy based on direct cooling of the coils
  • Universal scalable and modular combined inverter / charger (power range 3-22 kW)
  • Innovative accelerated inverter charger for faster “fast charging”
  • Efficiency improvement in PHEV cars (e.g. pre-conditioning, exhaust gas energy recuperation)
  • Wireless curb charging with thermal pre-conditioning (e.g. while parking) based on existing infrastructure in cities (power range 1-2 kW)
  • Safe multi-core control architecture for the powertrain computer including energy resource scheduler and advanced management of electrical, mechanical and thermal energies
  • Overall energy management including the before mentioned components and subsystems as well as the integration of 3D GPS data for energy optimal route selection

Progress beyond State of the Art

 

Standardization of the temperature levels of the different elements in the energy network will foster lower cost, higher efficient cooling solution and scalable systems and sub systems. The demonstrators will consider safety aspects and be evaluated with respect to robustness, by using fault injection methodologies.

eDAS will build an energy network within the FEV, making use of the available energy sources (electrical, thermal, mechanical), control them in an optimized way to feed energy back to the system and to minimize the impact of the external factors (temperature) by preconditioning of the car in order to achieve predictable and reliable mileage.

eDAS will provide solutions for predictable mileage exploring novel concepts such as using the combination of different also non electrical energy sources and storages in the FEV as a network of energy elements.

eDAS will also directly influence the battery efficiency by preconditioning of the car itself. Thermal conditioning will set for example the temperature of the battery to the best operating range for faster and thermal peak or overload free "Fast Charging" also protecting the battery by actively controlling State of Charge and State of Health. These aspects together will definitely minimize the uncertainty in range. For getting energy "en route" eDAS will provide novel concepts of direct interaction of the FEV with the available infrastructure in urban environments (Smart Grid) and by using the available navigation systems to plan the optimal topology for the route.

Finally, we will consider OEM’s requirements e.g. VW stated that the additional complexity and concepts for thermal managements must not add more than max. 20kg per 1000kg in weight to the car (class E-UP and class GOLF) and the cost need to be very closely monitored.

Supply Chains and Work Packages

 

eDAS is organized in Supply Chains (SCs) and Work Packages (WPs). Every SC is to deliver a demonstrator. The work is done within the WPs. Because every WP takes part in several SCs, information exchange and efficient working is ensured. There are partners, who are in charge of leading a WP or a SC. They are called WP- or SC-leader.

Click on the SCs and WPs to get further information.

 
 

Supply Chain 1 - Wireless Curb Charging

 

Within the eDAS project research activities on several crucial components of an electrical vehicle are bundled together to achieve higher climate robustness for pure electrical and hybrid vehicles.

Supply Chain 1 focuses on wireless energy transmission systems. These systems are commonly known, however the potential that wireless charging offers isn’t exploited yet. Wireless energy transmission within a power range of 5 to 1.000 W and an air gap from 1 to 15 cm has a lot of promising application potential, but research activities with this specification are limited. In fact, wireless energy transmission within this power level is not only beneficial for hybrid cars and EVs, but also for a lot of home and office applications, running in the same power range (see Figure below).

In this context, the Institut für Leichtbau und Kunststofftechnik of the TU Dresden performs research on the calculation techniques for efficiency mapping, as well as on the integration techniques to seamlessly integrate the wireless charging units into structural car parts. These techniques mainly influence the price and the tightly linked market penetration potential of a suchlike system.

By utilizing the power transfer system for thermally condition applications it shall become possible to use more of the battery capacity for traction purposes and less for climatisation. Thus the driving range can be boosted and a predictable driving mileage can be achieved. In combination with the research activities of the battery systems the overall system efficiency can be increased even further.

 

Supply Chain 2 - Innovative accelerated inverter charging

 

Objective

This supply chain will provide the AVL SFR inverter integrated in a test bed which allows the verification of function and software development for advanced inverter charging with wide range of power. In addition a prototype connectivity box to the grid will be developed. The system will be demonstrated in the AVL prototype vehicle.

  

 

Progress beyond state of the art

Today, typically AC charging methods for EVs are using On-board charging devices in addition to the existing powertrain propulsion inverter. In this proposal the powertrain inverter will be used for charging, which will reduce required devices in the vehicle.

 

Expected results and benefits

  • Reduction of vehicle costs, weight, reduction of vehicle cooling system (on-board charger typically needs to be cooled) as well as reduced system complexity.
  • Overall losses generated by using control units are reduced.
  • These effects are combined with a wide range of possible charging power. In general, the sum of these results will increase vehicle mile-range (by e.g. weight reduction).
  • Quantifiable result will be demonstration of advanced charging function on inverter test-bed as well as in AVL prototype vehicle.

 

Supply Chain 3 - Combined energy storage for electrical and thermal energy combined with enhanced energy management

 

Objective

  • Preparing energy storage for advanced usage in the vehicle.
  • Using an innovative material (PCM) the thermal management and related control functions can be improved. By re-using results of other program (battery module with PCM material, Gemac) this SC will provide the control unit (e.g. Aurix IFAG) and the integrated innovative thermal management functionality to operate the battery module on a test bed. The battery test-bed itself will also be provided for usage by AVL -A in this program.

Progress beyond state of the art


Today’s battery pack designs are based on different cooling strategies and functionalities which are key disciplines. Cooling systems and methods have strong impact on the size, cost and efficiency of the battery system. PCM material will be used in battery design and combined with advanced thermal management functions. This goes along with thermal simulation of the system as well as design assessment considering PCM integration.

 

 

 

Expected results benefits

Resulting benefits beyond state of the art will investigated, e.g. possible reduction of cooling system by using advanced functionalities combined with PCM material (cost, size reduction) as well as possible thermal energy distribution advantages (preconditioning, high load) in the vehicle or battery.

 

 

Supply Chain 4 - Common powertrain computer platform

 

Objectives

  • Integration of energy management applications to an overall resource management system for electric and thermal energy (ERM)
  • Provision of a Central Computing Unit (CCU) based on advanced AURIX® multi-core controllers, including in particular a Hardware Abstraction Layer (HAL) and a comprehensive Energy Resource Scheduler (ERS)


 

Description

One of the main tasks of the Supply Chain 4 will be the provision of an open and extensible CCU, hosting and integrating the central energy management applications developed by the eDAS project. The CCU hardware will be based on advanced AURIX® controllers, taking best effort of the powerful multicore architecture and the comprehensive safety features of AURIX®. The work will further include the development of a new Hardware Abstraction Layer (HAL), a comprehensive Energy Resource Scheduler (ERS) and base SW modules (e.g. drives). These components will be integrated together with an OSEK compliant real-time OS (ERIKA®), thus providing the basis for the implementation of the overall Energy Resource Management applications (ERM). The CCU development will further take into account the requirements of other projects, in particular the cluster projects iCOMPOSE and INCOBAT.

 

 

Work Package 3 - Elements of electrical and thermal energy generation, management, storage, recuperation and harvesting

This work package is focused on the design and experimental verification of the concepts developed in the eDAS project. The outcome of this work package will allow to show and to verify the projects' results with developed hardware on a test bench environment. Components like the battery pack, the electrical motor, inverters and chargers, will be engineered to exactly fit the holistic system approach of the project, where electrical, thermal and data flow are actively routed to achieve a significant improvement of the predictability of mileage.

This work package has identified two mobile applications of electrical drive trains, where a predictable mileage is crucial: automotive and aviation drive trains.
The picture below gives a short overview on the aviation drive train. The components addressed for this application are: battery monitoring, battery management as well as an on-board charger.

The diagram below shows the components in the automotive drive train, that will be characterized. This includes a battery system, a combined charger-inverter, a wireless curb side charger and an electrical machine along with an electrical control unit especially developed to coordinate the flow of information, including electrical and thermal energy flows.