News - EEHE 2017


April 09-11, 2018 in Münster/Germany
Further information:

6th eehe Conference –
Electrics / Electronics in Hybrid and Electric Vehicles and Electrical Energy Management
17-18.5.2017 in Bamberg

The performance capacity of 12V on-board networks has finally reached its limits. The start of series production of vehicles with an additional 48V system heralds a move to the universal use of two-voltage on-board power supply systems in the automotive sector. According to the most recent market forecasts, the basic system with starter generator, 48V lithium-ion battery and DC/DC converter will have a rapid market rollout in the next few years. Despite the high costs that were originally forecast, extensive market penetration is expected as the associated reduction in CO2 emissions is something all manufacturers will have to embrace.

Because of the shift of high-power loads from 12V to 48V and the introduction of new functions at the 48V level, a function and component landscape will develop at 48V, which will also have an effect on the E/E architectures of highly electrified vehicles such as plug-in hybrid and electric automobiles.

Participants in the eehe Conference – Electrics / Electronics in Hybrid and Electric Vehicles and Electrical Energy Management on 17-18 May 2017 in Bamberg will have the opportunity to meet all major players in this important future theme of automotive development at a single event. A further highlight here will be the accompanying trade exhibition. As in previous years, the event will be held in both German and English (with simultaneous translation).

All details of the conference can be found at

Your contact for the press release:
Bernd Hömberg, Head of Automotive Electronics
Leiter Fachbereich Automobil Elektronik
Phone +49 2 01 – 18 03-249

About HDT
Haus der Technik HdT serves as a platform for the transfer of knowledge and continuous professional development at the highest level. With more than 80 years of experience as an independent institute providing continuing education for specialists and managerial staff, HdT offers technical seminars, symposiums and in-house workshops to promote innovation and to provide for the transfer of know-how and expertise.

The original idea of the HdT founding fathers is still alive in the modern organisation. Our aim is to support companies to be successful in a competitive environment by offering services to knowledge workers.
HdT brings together science, research and industry. In partnership with RWTH Aachen University and the universities of Bonn, Braunschweig, Duisburg-Essen and Münster, HdT maintains close contacts with companies and research institutes, and is therefore a forum for the exchange of knowledge and experience.

07.02.2017 (09:00) – 08.02.2017 (17:00)
in Garmisch-Partenkirchen (Dorint Resorts)

Dipl.-Ing. Andreas Sehr
FEV GmbH, Aachen

Why you should attend this event

The conference will tackle various of these aspects, reviewing the state of the art and introduce interesting VCR solutions, among others the FEV VCR con-rod, with reference to different technical applications.

Apart from the deep insides into latest VCR Research and developments this new platform offers multiple opportunities for mutual exchange with reputable industry representatives and engineering experts.


The ongoing trend of downsizing and boosting of gasoline engines has already achieved impressive results however leads to an increased tendency of combustion knock at higher engine loads. Varying the compression ratio during engine operation is one measure to avoid this limitation and to enable the demand for increased torque and power with an improved fuel consumption in the entire engine map.

Varying the compression ratio on diesel engines results in reduced peak firing pressures and temperatures, beneficial for lowered thermo-mechanical stress and reduced engine-out pollutant emissions. This enables two different opportunities for VCR application. First option is to extend the power output on an already PFP limited base engine. Alternatively: Rightsizing the bearing dimension according the reduced peak firing pressure enables friction reduction and finally an improved fuel consumption. On top of these mechanical advantages, VCR provides potential to lower engine-out NOx under higher operating loads, important for optimal compliance of future RDE demands.

Dual fuel engines suffer from the compromise for the compression ratio. E.g. marine engines require a low compression ratio for the gas application while running most of the time on heavy fuel oil (HFO) where the high compression ratio would enable fuel consumption and operator cost reduction. Varying the compression ratio during engine operation is one measure to optimize efficiency for the different fuels.

Information and booking

Author: M. Eng. Stephanie Preisler
Co-author: Rainer Knorr
Further Information about the author

Die Einführung der CO2 Emissionsgrenzen in Europa sowie der Anstieg der installierten elektrischen Leistung in zukünftigen Fahrzeugen sind Auslöser für die Entwicklung neuer Systemlösungen. Das 12/48 V Bordnetz ist ein Ergebnis dieser Entwicklung. Durch die Erweiterung des 12 V Netzes um eine weitere 48 V Spannungsebene bestehend aus E-Maschine, Batterie und DC/DC können neue Funktionen realisiert werden, die die Einhaltung der geforderten Emissionsgrenzen unterstützen. Zudem steht mehr Leistung für die Versorgung von Verbraucher zur Verfügung. Bereits in den kommenden Jahren wird eine erste Variante der 12/48 V Bordnetzarchitektur von einigen Fahrzeugherstellern in Serie gebracht. Die erhöhte Rekuperationsleistung /-energie eines 48 V Systems im Vergleich zu einem heutigen 12 V System trägt dabei entscheidend zur Reduzierung der CO2 Emissionen bei, da diese Energie nicht über den Verbrennungsmotor erzeugt werden muss. Des Weiteren können durch die zusätzlichen Systemfreiheiten neue Fahrfunktionen, wie Coasting, eBoost und eLaunch, umgesetzt und die CO2 Emissionen weiter gesenkt werden. Der Erweiterung der Fahrfunktionen steht jedoch der steigende Grad der Elektrifizierung gegenüber. Zukünftige Bordnetze sollen mit weiteren elektrischen Komponenten, wie zum Beispiel dem elektrischen Klimakompressor, dem elektrischen Heizkatalysator oder einem elektrischen Kompressor, ausgestattet werden. Die heutige Auslegung von 48 V Systemen ist meist auf CO2 Reduzierung optimiert. Werden diesem System weitere elektrische Verbraucher hinzugefügt, kann dies zu einer Erhöhung der CO2 Emissionen führen und zu einer Destabilisierung des Bordnetzes führen. Zur Ermittlung der Querbeziehungen zwischen dem steigendem Funktionsumfang und der steigenden Elektrifizierung von Nebenverbrauchern wurden sowohl Simulationen als auch Messungen an einem 48 V P2 Hybridfahrzeug, bei unterschiedlichen Fahrsituationen und mit variierendem Bordnetzverbrauch, durchgeführt. Basierend auf diesen Ergebnissen werden die Grenzen und Möglichkeiten von zukünftigen 12/48 V Bordnetzen genauer betrachtet, analysiert und im Rahmen des Vortrages dargestellt.

Author: Dr. Stefan Lauer
Friedrich Graf (Dipl.-Ing.), Continental, Regensburg;
Dipl.-Ing. Moritz Springer, Ford Werke GmbH, Cologne;
Dipl.-Ing. (FH) Stefan Wechler, Schaeffler Technologies AG & Co.KG, Herzogenaurach

Further Information about the author

The presented propulsion concept targets the market between the 48 volt starter generator systems and high voltage hybrid systems. The demonstrator vehicle has an attractive cost/benefit ratio and increases its significance by the usage of a manual gearbox. In order to enable both CO2 savings and good drivability, in a holistic approach, a high power density gasoline engine has been combined with a 48 volt P2-hybrid system. The low end torque of the internal combustion engine is enhanced by an electric torque support allowing for an effective downspeeding. The central component of the P2 system is a hybrid module that provides an increased regeneration potential and an optimized operating strategy which enables a decrease in CO2 emission. The P2 system is in particular characterized by an axial-parallel arranged e-machine that is connected with the powertrain and an air conditioning compressor via a belt drive. Other ingredients include an automated drive clutch “K1” and another clutch “K0” for the decoupling of the combustion engine from the powertrain. The opportunity to offer an electric air conditioning without additional costs and moreover purely electric driving at low speeds are two of the most attractive functions of this P2 hybrid electric vehicle. With the e-drive option in particular the basis for automated parking is set also with manual transmissions. Finally the possibility of a comfortable engine start with the 48 volt e-machine, similar to a starter generator system, is maintained. Various maneuvers are considered and compared in a standard drive cycle with regards to functionality and drivability. Especially the experience of electric driving is assessed for this 48 volt P2 hybrid vehicle. Crucial for the success of this new concept is a completely new 48 volt P2-focused drive strategy and an energy management system that provides the foundation for the discussed 48 volt based functionalities.

Author: Dr.-Ing. André Körner
Co-author: Sebastian Kahnt
Further Information about the author

The future of driving will be increasingly electric. The next step will be 48V Mild Hybrid cars. Based on moderate costs and good CO2 saving benefit/cost ratio this allows a high number of cars to be using this system, thus reducing the total CO2 fleet emission substantially. The P0 Hybrid configuration, with the electric machine mounted similar to conventional alternators, allows easy integration in existing powertrains, because there is only little more space needed for the bigger electrical machine and for the water cooling, but it does not increase the length of the powertrain. Therefore it is an advantageous hybridization method for comparatively quick implementation in many car models or platforms. Passive engine-off coasting is known already without 48V Mild Hybrid Systems as an efficient CO2 saving measure in real driving. It is known to save less in WLTP, but unfortunately it does not allow emissions savings in NEDC. On the other side, active coasting, where an electric machine drives the car to hold the speed at a constant level, allows emission savings both in real driving and in test WLTP and NEDC test cycles. But for P0 Hybrids, active coasting requires dragging the internal combustion engine, what at first sight doesn´t seem to be efficient , considering the engine drag losses. Using car energy simulations, we demonstrate that a combination of active and passive coasting in a 48V Mild Hybrid car with P0 configuration saves substantially more fuel and reduces more CO2 emission than other utilization methods of the recuperated energy, such as active or passive coasting alone, or electric torque assist, or consumption of the energy in the electric 12V system. The influence of design variables like e.g. battery size, driving cycles and load scenarios is also evaluated and discussed. Validation of the simulation results is demonstrated by tests on an energy management test stand.

Author: Fabian Schipperges
Co-authors: tbd
Further Information about the author

Die Entwicklung und zunehmende Integration von Fahrer-Assistenz-Systemen bis zu Funktionsumfängen, die (hoch-)automatisiertes Fahren ermöglichen, bedingen die simultane Entwicklung neuartiger Energiebordnetze, die den erhöhten Anforderungen der Bordnetzverfügbarkeit gerecht werden. Das Energiebordnetz ist – stärker denn je – Teil einer sicherheitsrelevanten Infrastruktur. Insbesondere im irregulären Fahrbetrieb und in kritischen Ausnahmefällen muss das Energiebordnetz mit sehr hoher Verfügbarkeit eine Basis für einen sicheren und kontrollierten Fahrbetrieb gewährleisten. Eine erhöhte Verfügbarkeit des Energiebordnetzes erreicht man z.B. durch die Schaffung redundanter Versorgungszweige und geschickte Verteilung der Steuergeräte, die sicherheitsrelevante Funktionen bedienen. Zunächst wird ein Überblick über fehlertolerante Energiebordnetze gegeben. Dabei werden wesentlich zwei Ausprägungsformen unterschieden und deren fahrzeugbedingten Voraussetzungen aufgezeigt. Auf Basis der ISO 26262 werden zukünftige Ziele der funktionalen Sicherheit erläutert und Bezug auf die diskutierten Strukturen genommen. Unter Berücksichtigung der Erkenntnisse einer Energiebordnetzsimulation werden die elektrischen Anforderungen an elektrochemische und leistungselektronische Komponenten und deren Wechselwirkungen diskutiert. Hierbei werden insbesondere Last- und Fehlerszenarien berücksichtigt, die im Betrieb eines (hoch-)automatisiert fahrenden Fahrzeuges auftreten können.

Author: Johannes Maiterth
Dipl.-Ing. Peter Methfessel, VKA, RWTH Aachen University,
Dr.-Ing. Edoardo Pietro Morra, FEV GmbH, Aachen

Further Information about the author

In the European Union trucks, busses and coaches produce around 25 % of the CO2-emissions from road transport. Because of increased road freight traffic, the CO2-emissions rose by 36 % between 1990 and 2010. Therefore, it is planned to also limit and certify the CO2-emissions of new heavy duty vehicles (HDV). One solution to reduce the CO2-emissions of a HDV is to electrify the powertrain. Depending on the driving cycle, different fuel consumption improvements can be achieved with electrification of the powertrain. For a series hybrid bus, up to 33 % of improvement has already been demonstrated. For the fleet operator the potential fuel savings that can be achieved with an alternative powertrain on a daily route is crucial for the selection of the right type of vehicle. For the vehicle manufacturer knowledge about the expected driving cycles is important to size the powertrain parameters appropriate. Hence, different aspects have to be considered when designing hybrid powertrains. To exemplify an advanced development approach, considering the requirements of, both, the operator and the OEM to find a best cost/benefit solution, this paper demonstrates the optimization of an electric powertrain for a hybrid electric distribution vehicle. All components of the electrical powertrain, like high-voltage battery and electric machine are scalable in the simulation model. By means of design of experiments, not only a best compromise between fuel consumption and cost will be determined, but also the requested vehicle performance targets like acceleration from 0 to 50 km/h and climbing capacity will be taken into account. The simulation study will compare the results of a conventional powertrain on at least two different typical routes with a series hybrid and parallel hybrid powertrain.

Author: Ahad Ahmed Buksh
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A securely connected self-drive car aims to reduce its global CO2 footprint. At the moment, a lot of efforts are put in by the automotive industry to manufacture cars for a greener environment. Besides, Tesla’s breakthrough of elegant EVs is motivating vehicle OEMs like BMW, Volkswagen, Nissan, and others to step more rapidly into the EV business. According to IHS, fuel-efficient technologies and increased electrification will help car OEMs to facilitate environmentally friendly cars. Nowadays, a substantial amount of work is done on the exhaust aftertreatment systems to improve the fuel efficiency. For internal combustion engines, there is an increasing trend away from traditional incumbent multi-port fuel injection systems towards gasoline direct injection systems. This is simply because direct injection system increases the fuel efficiency of a vehicle. The prevailing concepts in the engine and the exhaust aftertreatment systems for internal combustion engines (ICEs) require sensors for their operation. The increase in sensor content will have ECUs with more inputs and this will push the need for intelligent controllers with higher speed operation and embedded memory. According to IHS, start-stop systems or so called micro-hybrids will outset the development of vehicle electrification on a large scale. Such a system, in which the engine turns itself off when the car stops at a junction or stop light, can improve the fuel efficiency up to 10%. This technology is already widely adopted by the European market but will also gain momentum in North America and Asia as each recognizes the importance of fuel efficiency and lower CO2 emissions. Increased vehicle electrification requires an alternative to the gasoline technology for driving the engine with the same amount of power. Thus, IHS sees 48V board-net bus technology as the next milestone to enable green car. This technology will allow a car to have functions such as recuperation, boosting, and sailing. A function like boosting would be achieved by the combination of electric motors working in tandem with the conventional engine. For this reason, the 48V technology would typically require three ECUs: a motor inverter for converting AC into DC and vice-versa, a DC/DC converter for bi-directionality, and a battery management system for supplying the 48V to the bus. Propulsion systems for electric and hybrid vehicles demand, on average, ten times more semiconductor content than a conventional engine. DC/DC converters for this technology would have to comply with ASIL-C requirement. In order to meet ASIL-C, as many as 18 MOSFETs would be needed to act as safety switches. With the rising levels of voltage levels on batteries for HEV/EVs, switching the voltage levels becomes a critical task for the power management components. MOSFETs, IGBTs, and diodes are growing in number to perform the switching functions. The high and low side driver ICs are needed to drive currents for the relays, injectors, and the different valves. Eventually, IHS perceives the battery management solutions to have a significant bearing in the cost of HEV/EVs. For instance, high-end EV brands like Tesla house around 7000 cells as opposed to Nissan Leaf which typically has around 192 cells. The presentation will cover the topics described above and its impact on the powertrain semiconductor and system level. It will talk about the developments and factors which are driving the changes within the propulsion system designs. It will also highlight how the electronics are powering the hybrid/electric and fuel-efficient vehicles.Last but not the least, the evolution in electronics which is enabling innovative architectural changes in powertrain of hybrid and electric vehicles will be discussed as well.

Author: M.Sc. Ajay Poonjal Pai
Co-authors: Dr. Tomas Reiter, Prof. Martin März
Further Information about the author

This paper evaluates the benefits of replacing the Si diodes of a commercial IGBT module for the main inverter application of an electric vehicle with SiC diodes, leaving the other components of the package and the system unchanged. This will give a direct comparison of Si vs SiC, without giving scope for discrepancies arising out of differences in the packaging, gate-driver circuit etc. The IGBT-module chosen for comparison is a low inductance (8nH) HybridPACK Drive module from Infineon, suitable for very high speed switching. The focus of the comparison is the following:  Static and dynamic characterization of the Si and hybrid-SiC modules.  Development of a loss model for the modules based on the above measurements.  Application of the developed loss model to investigate the performance for various drive cycles (Artemis, WLTP, NEDC).  Development of a novel calorimetric loss measurement setup for experimental verification of the results. Motivation Papers that address the topic of SiC for automotive main inverters often have one or more of the following drawbacks: The considered devices are rated for low currents, quite far from the typical application requirements of the main inverter The devices/packages chosen are prototypes, which do not face the same constraints a mass product would. The compared Si and SiC chips are in completely different packages or application conditions In short, a clear investigation of the benefits of using SiC as a plug-and-play replacement for a commercial Si-IGBT module is still missing in literature. This gap is attempted to be filled by the paper Results Fig. 1 shows an IGBT-diode pair of the compared HybridPack Drive module with Si diodes (the module will be referred to as “HPD”) and SiC diodes (the module will be referred to as “HPD-Hyb-SiC”) respectively. Static losses are measured with a curve tracer and the switching energies of both the modules are measured in a double pulse test setup (see Fig. 3). The SiC diodes help reduce E_on and E_rec by around 25% and 75% respectively. A loss model is derived based on these measurements and this model is used to calculate the inverter losses for Artemis, NEDC and WLTP drive cycles. As seen in Fig. 3, HPD-Hyb-SiC offers more than 10% reduction in losses for all the drive cycles. The Artemis Urban cycle with a reduction of around 20% losses sees the most benefit of using SiC diodes. Also, the inverter losses at different rms currents and dc-link voltages are measured in a novel calorimetric setup (see Fig. 2) introduced in the paper and the results are summarized in Fig. 3. It can be seen that there is no benefit of using the SiC diodes at V_dc=100V. At V_dc=300V, the benefits of SiC become prominent and this gap widens as we increase V_dc, and at V_dc=400V, 75A, we can see a reduction of around 7% in the overall losses. Also, the simulated losses are found to be in good agreement with the measured losses, thereby validating the loss model.