Are hybrid drives a compromise, or the best of both worlds?

In an optimal hybrid drive, the ICE and electromotive components can both use their advantages to the full. When they team up, the result is not a compromise but real added value. Examples include higher performance via boosting, or all-wheel drive via P4 hybridization. All with reduced CO2 emissions – and zero range anxiety.

CTI SYMPOSIUM USA asks questions and presents answers
The greatest strength of hybrid drives is their extraordinary versatility. The spectrum ranges from inexpensive 48-volt solutions right up to complex plug-in hybrids. Developers can create a wide variety of architectures, each in countless variants. Which alternatives look promising? Which methods are productive? What are the current trends? How about sustainability? At CTI SYMPOSIUM USA, hybridization is high on the agenda. With concentrated information in eleven sessions and exciting discussions in the plenum, our wide programme reflects this top topic in all its diversity.

Intelligent strategies: from specification to solution
Three different speakers will present examples of how, from a wealth of alternatives, developers can systematically filter out the solutions that best meet all application-specific specifications and development goals.

Programmed progress – comparing and improving
Due to the wide range of concepts possible in powertrain design, potential solutions often differ greatly. In his lecture, Christian Sieg (Technical University of Braunschweig, Germany) will show how developers can assess these alternatives precisely and objectively, then compare them. His analysis will focus on common powertrain concepts that are already available for the C, D and E market segments. In terms of complexity and characteristics, these concepts differ significantly. The speaker’s main focus will be on DHTs, which are set to play a particularly important role in future. Driving performance and efficiency are important comparison criteria when identifying promising concepts and powertrain designs; various benchmark parameters are also factored in. At the centre of the overall process stands a specially developed modular simulation model. This is coupled with an intelligent algorithm that saves developers computing time when they need to identify powertrain designs that will meet defined requirements for driving performance. Using the Simulation Tool Chain, they can run intensive optimization processes, compare and evaluate large numbers of hybrid powertrains in a short time.

Concept and components: success is in the details
Dr Stephen Jones (AVL List, Austria) will present a different path to finding the optimal solution for DHT powertrain configurations. The powerful, scalable methodology he will outline for given applications starts early on in the concept phase. In step one, the goal is to select the most promising candidates quickly from numerous configuration alternatives. After optimization, the next step involves a step-by-step, in-depth analysis of the performance characteristics of individual components, based on co-simulation. Using this combined ‘optimize and co-simulate’ approach, developers can identify the most promising powertrain configurations for a given application, then refine their definitions of component properties for optimal trade-offs between vehicle performance, driveability and comfort, fuel efficiency and emissions under both certification and RDE cycles.

In terms of overall efficiency, parallel, serial and power split configurations with DHT concepts that use the latest ICE technology (e.g. Dedicated Hybrid Engine) are broadly similar. Hence, there is probably no such thing as the ‘ultimate configuration’. Instead, developers need to evaluate various hybrid transmission concepts reliably and quickly in the early conceptual development phase. “Ultimately, the key to optimizing the whole hybridized powertrain for a given application lies in choosing the right characteristics for powertrain components, and ensuring their correct system integration” says Dr Stephen Jones.

Modular DHT platform designed with 2025+ in mind
Erik Schneider (IAV, Germany) will address optimal hybrid powertrain configurations for tomorrow’s vehicle fleets. The focus of his presentation will be a new, modular hybrid platform for transverse engine, front-wheel drive architectures in vehicles ranging from small cars to large SUVs. The first development stage involves discussing the general trade-off between hybrid functionalities, customer requirements, system complexity and costs. Next, the functional potentials and limits of various drive train topologies are characterized. Another focus point involves configuring combustion engines in an optimal way. Using the IAV Powertrain Synthesis methodology, developers can examine each of the predefined hybrid transmission topologies in a large number of parameter variations.

Erik Schneider will present the result of this systematic development process: a Dedicated Hybrid Transmission (DHT) platform with one and two electric motors and an optimal trade-off between performance, energy consumption and costs. The modular platform comprises both a single-motor DHT integrated in parallel, and an extended two-motor DHT that increases electrical output and extends the functionality to a combined hybrid, including serial hybrid mode. An electric rear axle can also be added, opening up the possibility of electric all-wheel drive. This detailed presentation of the design of the platform and its key subsystems (basic mechanics, on-demand actuators, electric motors, power electronics and batteries) is sure to yield interesting insights.

Sustainable powertrain systems for tomorrow: from scenarios to technical solutions
Next-generation powertrains will be shaped by stricter global CO2 legislation on one hand, and altered mobility requirements of consumers on the other. Expectations that future powertrain systems should contribute to sustainable mobility are growing in urgency.

“The demand is for mobility offers that are geared towards the needs of end customers,” says Dr Christoph Danzer (IAV Germany) in his lecture. The methodology he will present starts by taking a holistic look at mobility. Among other things, it examines how market and environmental policy requirements affect user behaviour. Multiple hybrid and pure electric drive systems can then be generated, based on different mobility scenarios. In the next step these are systematically optimized, whereby parameters including CO2 balance (tank-to-wheel, well-to-wheel, cradle-to-grave), use of primary energy and production costs are factored into sustainability calculations. Ongoing fleet-level optimisation of powertrain settings is also important. The goal is to develop platform systems with a minimum of carry over parts for hybrid and electric vehicles, and to reduce overall costs. Finally, modular powertrain systems are assigned to different vehicle segments. The last link in this innovative Tool Chain involves combining ICEs with DHTs and one or two electric motors in different e-axle configurations, using transmissions ranging from single-speeds to stepless multi-speeds. In his lecture, Dr Christoph Danzer will present mobility scenarios updated specially for the US market, and will make interesting forecasts for 2030.

Electrified AWD – efficiency on four wheels
Particularly in North America, many people see all-wheel drives (AWD) as a must-have feature. Reasons the topography and climate, as well as customer requirements. However, conventional AWDs that are powered solely by the ICE increase fuel consumption. In his lecture, Simon Kaimer (Magna Powertrain, Austria) will speak in favour of electrifying all-wheel drive systems. He will describe the system approach required to control functionality and costs. Important topics include electrified and mechanical standard components, integrating vehicle dynamics into the system software, reducing hardware complexity, and options for OEM-specific functional designs. The hybridized all-wheel drives he describes can reduce fuel consumption while maintaining – or even increasing – the benefits of AWD. AWD has a positive effect on longitudinal and transverse vehicle dynamics. This in turn delivers important benefits such as more traction, driving fun and safety, as well as improved climbing and towing capability. Further benefits derive from customer-specific solutions for different user requirements. From inexpensive 48-volt systems to high performance and off-road drives (plug-in and high voltage) or electrified torque vectoring, the combination of hybrid drive and AWD is proving to be a versatile and efficient double act.

48 volt hybrid platform – low voltage, high efficiency
48-volt hybridization offers compelling advantages for developers seeking to achieve high benefits with relatively low effort. Dr Thomas Hackl (Magna Powertrain, Austria) will present a new modular, scalable 48-volt platform and explain the individual stages of the development process in detail. The integration-friendly concept is characterized by high recuperation potential, and offers customers the benefits of traction support and limited-range all electric driving. In the first project phase, an overall P4 system with a maximum engine speed of 50,000 rpm was successfully bench tested. During the subsequent upscaling to customer requirements, factors such as efficiency, service life, cooling, and NVH and EMC behaviour were optimized with the aid of detailed simulation methods. These included the Smoothed Particle Hydrodynamics (SPH) method for thermal management simulations. In the next step, a platform was designed for series production. This platform covers motor speeds from 20,000 to 35,000 rpm, and a power spectrum from 17kW to 25kW. The external diameters of this motor platform are 125mm to 166mm; it will mainly be used in applications with highly demanding package requirements in P2.5, P3a and P4 architectures. Depending on vehicle and system configurations, 25kW systems of this kind can yield CO2 benefits of up to 21%. The platform delivers superior power density, a unique high-speed curve up to 35,000 rpm, and excellent overall efficiency.

CTI SYMPOSIUM USA – the shortest route from problem to solution
On the one hand, developers need to make decisions faster all the time; on the other, the problems they face are growing more complex by the day. CTI SYMPOSIUM USA is the ideal platform for up-to-the-minute, practical information. The topics we present today in our specialist lectures could well be conquering the markets tomorrow. Find just the component you’ve been looking for at the digital CTI SYMPOSIUM EXPO. Make new contacts and stay connected, even in these challenging times, with a platform that’s custom-built for intensive networking.