Skip to main content

Über dieses Buch

Inhaltliche Schwerpunkte des Tagungsbands zur ATZlive-Veranstaltung "Der Antrieb von morgen 2020" sind elektrifizierte Antriebsstränge, Wasserstoff in der Fahrzeugtechnik sowie Systems Engineering. Die Tagung ist eine unverzichtbare Plattform für den Wissens- und Gedankenaustausch von Motoren- und Fahrzeugherstellern, deren Zulieferer und Entwicklungspartner, Lehrende und Ingenieure von Universitäten und Hochschulen, Vertreter von Behörden und Verbänden sowie für Techniker, die in diesem Themengebiet aktiv sind.



The Shift to Electrified Drivetrains is a Fact – Only the Technology Remains Open

The last years have been strongly characterized by concerns about the rising temperature and the acceleration of climate change. The international consensus is that we need to limit the global warming to 2 degrees Celsius. This target is reflected in the strict CO2 legislation around the globe.
Jochen Schröder

From Mobility Demands to Future Powertrain Platforms

The future powertrain mix will be derived above all from a CO2- and emission-optimized vehicle fleet. The results of a powertrain variation study show that a scenario with high HEV share in the fleet is robust in regard to the external boundary conditions, particularly the electricity mix and the share of renewables. The high share of combustion engines also makes it easy to reduce CO2 emissions using synthetic fuels. A low share of PHEV, BEV and FCV also results in reduced manufacturing costs on the powertrain level. Furthermore, the analysis which powertrain mix would be expedient for WtW-CO2-legislation. Finally, modular powertrain systems were allocated to various vehicle segments to allow for a combination of combustion engines with dedicated hybrid transmissions with one or two electric motors and various electric axle configurations from single-speed to seamless-shifting multi-speed transmissions.
Christoph Danzer, Torsten Semper, Jörg Müller, Erik Schreiterer, René Kockisch, Erik Schneider, Wolfgang Wukisiewitsch, Marc Sens

HV Architecture Solutions for High Efficiency Inverter

Main drivers for EV architectures are vehicle range, charging functionality and powertrain cost as shown in Fig. 1.
Philip Brockerhoff

Front Loading Approach in Battery Development for Generation Update

Automotive OEMs are facing many challenges today. One of them is to rapidly increase within the next couple of years, the portfolio of their electric vehicles, and to do this, in the shortest possible development time and with the minimum occurred costs. Considering the battery as one of the critical components within the electric powertrain, the solution is to approach battery development for new electric vehicles based on an already existing battery pack project. The battery development process at AVL (AVL GBDP – Global Battery Development Process) is implemented within a project organization structure, having defined quality-gates and time triggered milestones, with defined activities and deliverables that will be synchronized, checked and reported at each quality gate and milestone review. Having the GBDP, as the basis of a lead battery development, this paper will provide an analysis of how front-loading can support the development of derivate battery packs during an generation update.
Nenad Dejanovic, DI Paul Schiffbaenker

ChargeBIG – Charge as Fast as Necessary, Not as Fast as Possible

The power industry has to face several challenges regarding energy production and distribution, especially due to the rapid expansion of renewable energies, reduction of base-load thermal power plants, and an increasing fleet of battery electric vehicles. Discussing the challenges of battery electric vehicle charging, it is often ignored that even today these vehicles can be utilized as an adjustable load. And the quality of the energy supply can be measured by anyone checking grid voltages and grid frequency. MAHLE and its partners strive to prove the effectiveness of a new, cost effective, large scale charging infrastructure utilizing existing power grid connections, and at the same time providing grid friendly load adjustments. Charge as fast as necessary, not as fast as possible, is the key for battery electric vehicle success. This project is publicly funded by the BMWi „Sofortprogramm Saubere Luft 2017–2020“.
Sebastian Ewert, Walter Krepulat, Max Gerstadt, Hauke Stamer

P0 Mild Hybrid – Pushing Limits to Maximize Benefits

When a belt-alternator-starter (BAS) is used in a classic front-end-accessory-drive (FEAD), this is referred to as a “P0 mild hybrid”. In the recent past, P0 mild hybrids were 12-V belt start-stop systems. Meanwhile, current developments show that future FEAD applications will mostly incorporate a 48-V or high-voltage (HV) BAS to fulfill more stringent CO2 regulations.
Christoph Schröder, Bertrand Pennec

48 V High-Power Battery Pack for Mild Hybrid Electric Powertrains

Mild hybridisation, using a 48 V system architecture, offers fuel consumption benefits approaching those achieved using high-voltage systems at a much lower cost. To maximise the benefits from a 48 V mild-hybrid system, it is desirable to recuperate during deceleration events at as high a power level as possible, whilst at the same time having a relatively compact and low cost system. This paper examines the particular requirements of the battery pack for such a mild-hybrid application and discusses the trade-offs between battery power capabilities and possible fuel consumption benefits. The technical challenges and solutions to design a 48 V mild-hybrid battery pack are presented with special attention to cell selection and the thermal management of the whole pack. The resulting battery has been designed to achieve a continuous-power capability of more than 10 kW and a peak-power rating of up to 20 kW. The pack has been built and has been subjected to a series of tests at a range of ambient temperatures. The performance of the pack has been validated and the main characteristics, such as the internal resistance and capacity have also been established. The performance targets for the pack have been achieved. Further testing is underway to fully characterize the pack’s capabilities and characteristics, after which it will be installed into MAHLE’s 48 V eSupercharged demonstrator car.
Neil Fraser, Martin Berger, Jonathan Hall, Stephen Borman, Benjamin Hibberd, Mike Bassett, Simon Reader

Nissan Future Powertrain Strategy for a Sustainable Society

In recent years the automotive industry has faced parallel and sometimes conflicting challenges of having to drastically reduce CO2 and real world pollutant emissions in order to realize a healthy and sustainable society. Nissan’s proposed solution is a unique 2 pillar powertrain electrification strategy. The 1st pillar is BEV (Battery Electric Vehicles); Nissan led the automotive industry with the world’s first mass production BEV. Now, with the new 3rd generation “LEAF e+”, Nissan has a high performance product at a practical price. The 2nd pillar is “e-POWER” which provides all electric drive, with the electric power for the motor generated by an ICE. e-POWER gives the best customer satisfaction by providing a full “EV driving experience”, with good performance, without having to rely on a charging infrastructure and without a high cost premium. As a result Nissan has achieved best-segment sales figures in the Japanese market by applying e-POWER to a number of its models, such as the “NOTE e-POWER” and “SERENA e-POWER”. In this paper Nissan’s strategy, and its clear benefits, for both the environment and its customers, will be explained.
Masaaki Kubo

Use Case Optimized Hybrid Powertrains – The Agony of Choice?

The electrification of the powertrain makes a significant contribution to reduce the fuel consumption of vehicles. The solutions offered on the market range from mild hybrid electric vehicles (MHEV) across plug-in hybrid electric vehicles (PHEV) to battery electric vehicles (BEV) or fuel-cell electric vehicles (FCEV). Additionally, synthetic fuels (eFuels) are possible solutions for well-to-wheel CO2 neutrality.
Ferit Küçükay, Christian Sieg, Axel Sturm

Model-Based Approach to Identify Optimal HEV Drivetrain Configurations using Different Operating Strategies

In this paper the stepwise approach to a determination of an optimal hybrid powertrain configuration is explained. In a first step, a backwarded simulation with Dynamic Programming is used to determine a number of CO2-efficient topologies. In a further step, the level of detail of the simulation models is increased using a backwarded simulation with an ECMS approach. At a least step, the results of the first steps are verified using dynamic simulation models and a (MO-) ECMS. This ensures that the number of configurations to be calculated is constantly reduced over the detailing-stages. This procedure should make it possible to handle the variety of possible hybrid topologies in the design of a powertrain while keeping the computation level low.
Ralf Kleisch, Felix Günther, Michael Bargende

TwinRex – The TwinConcept for a Serial-Parallel Hybrid System With an Excellent Cost-Value Index

The TwinRex concept was developed as a dedicated hybrid system capable of meeting upcoming CO2 regulation. The simplified transmission consists of a two gear-transmission, with a reduced number of parts, in order to achieve a good compromise between performance, weight and cost. Two Motor-Generators (MGs) are integrated into the transmission, enabling hybrid functionality with three different driving modes (EV-Mode, Series-Mode and Parallel-Mode). Depending on the sizing of the MGs different degrees of hybridization can be achieved. We conducted a design study considering a set of standard use-cases to determine the CO2 reduction potential for the system, which is up to 19%. Simulation results show that WLTC can be handled even in layouts with low-power ICE and MGs. Moreover a right-sizing of the MGs is discussed under consideration of the possible applications of the transmission system. We show that this new concept provides a good cost-value index, helping to fulfil future CO2 emission legislation and achieve maximum end-user satisfaction. Additionally an improvement in acceleration and drivability was shown due to a predictive engine start and gear shift strategy.
Rene Savelsberg, Johannes Moritz Maiterth, Ruben Keizer, Farouk Odeim, Georg Birmes, Andreas Balazs, Matthias Thewes, Johannes Scharf, Andreas Sehr

A New Dynamic Approach for the Design of Energy Management Strategies for Hybrid Electric Vehicles

This paper presents a method to compute an approximation of actual internal combustion efficiency which is real time capable. Further, the implementation of this efficiency prediction into a hybrid electric vehicle energy management strategy is shown. It enables the computation of the optimal torque split under any varying condition. This real time capable approach, validated on the engine test bench, allows efficient operation of hybrid electric vehicles under real driving conditions. Research results show that, especially under conditions relevant for engine-knock, the potential fuel reduction is up to 10 % compared to actual known operating strategies exists.
Bastian Beyfuss, Peter Hofmann, Bernhard Geringer

Approach for Online Design of Experiments with Additional Constraint Modeling

The model-based optimization with empirical models is the state-of-the-art method for handling complexity in powertrain calibration. The test plans, used for the identification of these black-box-models, are designed before the test execution. This procedure requires expertise and prior knowledge about the process to be identified (offline). The kind of planning algorithm and the number of test points are highly dependent on the expected process behavior. If the results are not as expected after the test execution, a new iteration of the whole process of test planning and execution is performed.
To prevent those time-consuming iterations, the test plans can be created adaptively during the test execution (online). In [1] a method to actively place measurement points based on hierarchical local model trees (HiLoMoT) was introduced. In [2] this approach was used to actively learn models for more than one output dimension. The method proved to be advantageous for automotive applications: The number of measurement points for identifying the models is reduced. Furthermore, the expertise and prior knowledge, needed to apply these methods, are decreased.
In [3] an approach permitting or forbidding measurement points due to a constraint model was introduced. This method is called Online-DoE with Constraint Modeling (ODCM). It uses all measured points to predict whether a constraint is exceeded and decides online whether the next offline-planned measurement point is skipped. The method was applied to an engine calibration problem.
The following contribution combines both approaches and shows a calibration use-case. During test execution, measurements of the dynamic behavior of the drivetrain are evaluated using objective static criteria. This enables the usage of described algorithms, which are restricted to systems with static input-output-behavior for dynamic calibration applications. The HiLoMoT-model actively learns and places new measurement points. An algorithm similar to the ODCM-Algorithm prevents placement of measurement points in domains where the constraints are exceeded. The results of the drivability calibration use-case are presented and discussed critically.
Adrian Prochaska, Julien Pillas, Klaus Lüpkes, Yagiz Dursun, Reiner Pätzold, Bernard Bäker

Definition of The Optimal Battery Capacity of a Fuel Cell Vehicle

The polymer electrolyte membrane fuel cell system is subject to dynamic requirements in mobile applications in vehicles, which are in conflict with the lifetime of the fuel cell. Therefore, a battery is installed as an electrical intermediate storage for the operation of the system. An iterative inversion was performed to determine the optimal capacity of this battery and to derivate the dynamic requirements of the PEM fuel cell. For this purpose, a reference vehicle with polymer electrolyte membrane fuel cell was implemented in the simulation environment Matlab / Simulink. The model is based on a PEM fuel cell model, which describes the physical and electrochemical interactions within the cell. In the next step this model was integrated into a complete vehicle model, whose parameters within the simulation model were adjusted according to the comparison vehicle. The legal driving cycles NEDC (“New European Driving Cycle”) and WLTP (“Worldwide harmonized Light Vehicles Test Procedure”) were used for the calculation. The ascertained and evaluated data sets provide information about the maximum and minimum required battery capacity of a fuel cell vehicle system while stationary and dynamic operation. In the future, the dynamic requirements – for the fuel cell and the associated system components – can be scaled generically for any vehicle taking into account the battery capacity with the simulation model.
Swantje Konradt, Arne Lazar, Hermann Rottengruber

Efficiency Potentials of Fuel Cell Propulsion Systems

A clear transition from carbon-based energy sources and energy carriers towards renewable and carbon-free energy carriers is necessary in order to meet the climate goals set in the Climate Change Conference in Paris 2015. Hence, the consistent decarbonisation of all sectors of our economy is mandatory, e.g. in mobility and transport, for households and in industry. Electricity and hydrogen are the only two energy carriers that can be produced and used in an emission-free cycle. Particularly in mobility and road transport, battery electric vehicles for short range and fuel cells electric vehicles for long range and fast refuelling are offering the possibility for a complete decarbonisation. When high driving range is required, fuel cell vehicles achieve lower costs at high production volume compared to battery electric vehicles. Moreover, fuel cell vehicles feature significant advantages regarding rare resources and recycling. However, high improvement potentials especially concerning overall efficiency, costs, industrialisation, materials etc. are still existing.
As a starting point this paper provides an overview of the status of technology of fuel cells and hydrogen in mobility and road transport. Regarding efficiency analyses, the focus is put on a novel method for evaluating the fuel cell system efficiency using energy and exergy analyses. This innovative approach is based on sophisticated exergy analyses to determine efficiency potentials from fuel cell stack up to fuel cell system level including the auxiliaries – BoP components. In addition, the results are structured into physical, chemical and kinetic efficiency potentials. In this context examples for passenger car as well as for heavy duty applications are presented. As the thermal management of FC propulsion systems is decisive for enabling high efficiencies this method further allows detailed thermodynamic investigations for a single component as well as for entire propulsion systems on a scientifically established basis. Furthermore, the well-to-wheel as well as life-cycle CO2 emissions of FCEVs in comparison to other powertrains are analysed. This comparison includes passenger cars, busses and trucks.
Alexander Trattner, Marie Macherhammer, Klaus Esser, Patrick Pertl

Fuel Cell Systems for Rail Applications: Development Trends and Challenges

Besides battery electric powertrains, fuel cell electric powertrains are considered as a possible solution for zero local emission mobility for both road and rail vehicles. Depending on the particular use case, various components of the fuel cell system have to be designed to meet the customer requirements regarding system power, efficiency, cost, reliability, availability and durability. Apart from the scaling of one or several fuel cell stacks, the development process includes the design of the peripheral components in the air-, hydrogen- and coolant-paths of the fuel cell system.
Compared to the application of fuel cell systems in passenger cars and commercial vehicles, the implementation of fuel cell systems in railway vehicles affords advantages as well as new challenges.
The rail-bound traffic is characterized by approximately repeating driving cycles, since railway vehicles usually complete a daily schedule defined by the train operator. Improving the energy management for a particular train route can effectively reduce overall energy consumption. Furthermore, a majority of a fuel cell system’s waste heat can be utilized to heat the passenger compartment at low ambient temperatures. Despite the frequent stopping times in railway stations, degradation accelerating start-stop cycles of the fuel cell system can be reduced due to the high power demand of the auxiliary components and the possibility to charge the traction battery.
However, the long life cycle of rail vehicles, their demanding duty cycles and the goal to reach cost parity with diesel-powered trains pose major challenges. Compared to passenger cars and commercial vehicles with average operating periods of 8000 h respectively 25,000 h, the fuel cell stack and its peripheral components in rail vehicles should reach operating periods of up to 30,000–40,000 h. To meet these requirements, the degradation rate must be significantly reduced to prevent the replacement of the fuel cell stack or other system components before the end of their service life. Due to the need to recognize critical operating conditions and faults early as well as to predict the remaining useful lifetime and enable condition-based maintenance, the application of ‘Prognostics and Health Management’ (PHM) becomes increasingly important.
Marius Walters, Andreas Sehr, Steffen Dirkes


Weitere Informationen

Premium Partner