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General Introduction and Classification of Electrical Powertrains

Johannes J.H. Paulides*, Laurentiu Encica, Sebastiaan van der Molen and Bruno Ricardo Marques

Advanced Electromagnetic Group, Waalwijk, The Netherlands

Abstract

Did you know that all functionalities of our body are controlled by smart, super-intelligent, electrical systems? We actually do need these multi- billions of electrical signals in our nervous system to transfer the information via our central and autonomous nervous system to maintain and control, organs, muscle functions, and brain and spinal cord operation. The origin of these signals are actually electrochemical potentials that are perceptive in the nerve cells. The measurement of such electrical signals and potentials in the nerve transmission (similar to bodily responses) contains extremely valuable information of both the source as the receiver. Why start a powertrain book like this? Maybe it will become clear if we talk about an electrochemical battery and a receiving and returning powertrain? Anyhow, we wish you all the pleasure of reading/studying this book; it might be full of surprises and different points of view, but we trust that you will learn a thing or two.

Keywords: Electrical machines, electric drives, electric vehicles, micro-mobility, design process

1.1 Introduction

Electrical mobility is not only controlled using electrical systems, but supplied by electrical currents and sometimes even energy is firmly stored in permanent magnets, loosely stored in capacitors or temporarily stored in batteries. To achieve the efficient control of electrical power-trains, we mainly use bytes grouped in open-CAN messages that are transmitted by electrical pulses. We also need multi-billions of these electrical signals to control the powertrain over its entire lifetime, as shown in Figure 1.1.

The sources of these communication electric signals are voltages (Joules) that, for example, find their electrochemical origin in batteries, and can be (temporarily) stored in capacitors. Measurements of these voltages and currents from the battery to the inverter and from the inverter to the motor provides extremely useful information about rotor position, temperatures, state of health, bearing deterioration, efficiency, inductance matrixes and other motor parameters, partial demagnetization, winding deterioration, cooling, winding resistance estimation, condition monitoring, etc.

Figure 1.1 Multi-billions of electrical signals are transported through our nervous system [1].

Figure 1.2 Electrical pulses with an electrochemical origin? In this case maybe the Flintstone mobile should be considered as the first electrically propelled vehicle? [2].

In the context of electrical pulses that have an electrochemical energy storage origin, the Flintstone mobile might represent the first electrically propelled vehicle, as shown in Figure 1.2. In this respect, even walking could be classified as electrical mobility. However, a more common way is to classify mobility based on its electrochemical energy storage. As such, one of the earliest "controllable" energy storage device seems to be the "Leyden jars" that stored high-voltage electric charges (from an external source) between placed conductors on the outside and inside of a glass jar. Could this be considered a first in the sense that electrical energy became (kind of) mobile or could be deployed in a useful manner in an electrical network? Of course, batteries followed and this started electrical mobility. Today, electrical mobility, as shown in Figure 1.3, is something we take for granted on our roads, but the "road" to get where we are today was not so straightforward. Here we see the influence that we, as modest users with seemingly little influence, still have on getting a seemingly impossible-to-move and extremely powerful automotive industry to radically change! Although very few people thought it possible to alter the automotive industry, it did happen. We can agree or disagree on all the environmental influences of electrical mobility, but at the least it does remove pollution from distributed exhausts to an energy generation location and additionally allows for the "local use" of "local" energy generation sources. Only if such centralized or distributed energy generation sources become really sustainable will we all benefit. The main reason why electrical energy has proven to be a very useful form of energy is that it has the "potential" to be transported with almost 100% efficiency over relatively long distances. Meanwhile, what remains one of the challenges to be solved in the 21st century is creating (mobile) electrical energy storage, since electrical energy is not easily stored and therefore mostly needs converting to another form of energy to allow bidirectional utilization.

Figure 1.3 Electrical mobility is something we take for granted on our roads.

We all know that transportation of people and goods will change very rapidly both in the short-term and long-term future. As such, green thinking, self-driving vehicles, and urbanization are just a few contemporary trends that will change transportation. Particularly important are the automotive industry business models to create solutions that will address current and future mobility trends. A vehicle with a 1980s user interface is not acceptable anymore for current customers that are used to mobile phones, interactive television and advanced domotica within their houses. Therefore, a shift from being a traditional car manufacturer with a business model focused on product sales toward being a provider of mobility services seems to be one promising approach. Furthermore, stricter legislative restrictions provide new challenges that will encourage (or even require) highly efficient and effective vehicle development solutions. New technologies, such as low energy loss tires, autonomous driving, vehicle driver interaction, the internet of things, and powertrain-specific technologies, provide a huge number of possibilities to optimize the way vehicles and the environment interact. Further, lifetime analyses and environmental considerations, as shown in Figure 1.3, will also be key enablers for sustainable mobility and influence the development, manufacturing, use, and recycling of vehicles.

This chapter provides a mobility systems overview and will try to identify their future challenges from both a contemporary, legislative and future perspective. The integration of electric components into the automotive powertrain enables completely different powertrain architectures and configurations to be designed. These components also enable additional powertrain functions such as engine start-stop operation, silent power-trains, complete frictionless regenerative braking, electrical anti-lock braking, electrical differential and all these with new interfaces to the driver. Advanced or fully autonomous driver assistant systems are either under development or already on the market and require new interfaces to the vehicle and even new ways that vehicles might be used in the future, e.g., car sharing, vehicle robots, and driverless cars.

Figure 1.3 We need to think more about possibilities to optimize the way vehicles and the environment interact.

Future trends will lead to a higher diversification of powertrain systems with complex and altering software functionality, extendable or adjustable firmware and hardware, and advanced control or remote operation opportunities. This in turn results in higher powertrain software and commutation complexity and increased overall development effort. There is a need to know the most relevant powertrain functions, architectures and powertrain elements. Also, which development challenges are resulting from this powertrain system diversity? The automotive electrification provides rapid changes to powertrains, and such transformation brings engineering design challenges to consider integration, remote access and advanced control of these electrified elements. Powertrain-related targets are achieved by altering and harmonising various powertrain elements. Powertrain engineers will face new challenges in the design and manufacturing of batteries, e-drives, transmissions, low loss and long lifetime tires, body shapes, capacitors, contactless charging (even during driving), solar cells, and maybe fuel cells. System engineering will remain of utmost importance to take advantage of and understand all possibilities of (and in) electrified powertrains. The vehicle energy minimisation of subsystems as thermal management system, electrics/electronics (E/E), powertrain, body, chassis, or driving assistance will increase as interacting functions and (mechatronic) systems continue to increase, both in absolute numbers, as sales arguments. Therefore, we need to adjust, monitor, continuously coordinate and optimize development tasks across departments and (in the past considered impossible!) even beyond company boundaries. Managing the powertrain development complexity in term of organization and technology and considering its interfaces both upwards to vehicle development and downwards to the powertrain's elements and their manufacture will require a structured powertrain development processes that must be followed in the future accordingly. Simply focusing on individual elements or even subsystems and not considering the process and technical interfaces between them will...