Book Review: “Electric Powertrain—Energy Systems, Power Electronics and Drives for Hybrid, Electric and Fuel Cell Vehicles"


Dr. John M. Miller, Industry Consultant

Dr. John M. Miller

My over-arching comment, having thoroughly read this amazing book, is that I cannot improve on the authors' own assessment, but I will offer an independent critique below. The book was years in preparation and reflects the authors’ own wealth of industrial and academic experience. First, the authors’ prologue.

This is primarily an engineering textbook covering the automotive powertrain, energy storage and energy conversion, power electronics, and electrical machines. A significant additional focus is placed on the engineering design, the energy for transportation, and the related environmental motivations and impacts. The book is both an integrated and holistic university teaching textbook, from undergraduate to introductory postgraduate levels, and an educational and research reference for our industry colleagues.

 

Electric Powertrain book cover

 

This textbook is an educational tool for practicing engineers and others, such as transportation policy planners and regulators. This material is also written to be of interest to the general scientific reader, who may have little or no interest in the power electronics and machines. The general reader can read the introduction to each of the chapters and move to the next as soon as the material goes beyond the reader’s interest.

While the technical topics are diverse, the technical content and teaching paths are narrowed and focused by concentrating on the existing and emerging technologies for the technology evolution underway in the automotive industry. The focus is on cars, trucks, and buses. However, the amazing electric vehicle Mars rovers are also considered, especially the Opportunity, a rover which finished a marathon on Mars in 2015 after 11 years (and which featured in the movie and book The Martian).

The textbook results from almost three decades of collaboration between Dr. John Hayes of University College Cork, Ireland, and Dr. Abas Goodarzi of US Hybrid in California. John and Abas previously worked together on the General Motors’ electric vehicle, the GM EV1, the first production electric car of the modern era.

It has been almost three decades since General Motors (GM) displayed the Impact concept car at the Los Angeles Auto Show in January 1990. The Impact inspired the design of the GM EV1 and for California to subsequently issue its zero-emissions mandate. The EV1 became available for leasing in 1996 and demonstrated to the public that electric cars were feasible. It would require very considerable education for the electric car to go mainstream, and in fact, it still does.

The automobile is a complex machine that has been continuously refined ever since Henry Ford rolled out the first Model T in 1908 as an affordable mass-produced vehicle. By the 1990’s the motoring public was accustomed to the automobile’s refined propulsion and highly tuned ride and handling. Replacing the internal combustion engine (ICE) and gasoline tank with an electric traction drive and relatively massive battery pack constituted a quantum jump in engineering for manufacturers to just stay on par.

Dr. Hayes and Dr. Goodarzi have focused their considerable talent and experience on teaching the inner workings of the electric car. Readers, whether engineers, students, or the interested public, will find this book a treasure trove of knowledge on modern automotive technology. The book is divided into four parts in 16 chapters, starting with Part I Vehicles and Energy Sources. This section is actually a standalone, concise description of what it means to say a more highly electrified automobile. Here the reader is taken on a path that traverses our present dependence on fossil fuels and CO2 emissions of the ICE into the world of fuel cells and battery energy storage as the electric fuel for the traction motor. What is most refreshing in all the chapters of this book are the worked examples, plus the exercises that delve more deeply into each topic. But not just the fact that the examples are relevant to each section but that specific examples and problems get further refined as the reader moves into each new section of the book.

 

An Overview of the Book's Sections

Part I of the book sets the stage that hybrid, fuel cell, and battery electric vehicles must match or exceed the expectations of modern drivers.

Part II, Electric Machines, is a painstaking deep dive into the four main players in electric traction motors: brushed dc, induction (asynchronous), surface permanent magnet, and interior permanent magnet types. Engineers familiar with electric machines will find these chapters an ideal refresher, students will find the topics fascinating, and the informed layperson will garner a deeper appreciation of how that stored electric fuel gets converted into mechanical energy.

Part III, Power Electronics, is a more esoteric topic as many readers wishing a deeper understanding of the electric car will view these chapters as really getting “under the hood”. This is the world of power converters, inverters, and how they are controlled. Most will recognize these 5 chapters as a real strong suite of the authors because of their ability to describe with such clarity the DC transformer and AC synthesizer. The reader will be led by an expert hand through switch mode power conversion and be shown the intricacies of the complementary behavior of active (transistor) and passive (diode) switching devices. Examples again will reinforce their knowledge of not only computing the average and rms quantities of signals but of realistic power dissipation and efficiency computations. All extremely beneficial to the practicing design engineer and fundamental to understanding by the student and inquiring reader. My favorite chapter was on battery charging because of the need to not only understand the role of power factor correction (PFC) to meet utility grid power quality regulations but also to minimize ripple exposure of the battery. Some will need to dust off their control theory as the examples in chapter 15 get into tuning the inner current/torque loop and what can be a finicky outer voltage/ speed loop for the electric vehicle drivetrain.

Part IV, Basics, is another standalone section but this time in a single chapter on electromagnetism and energy conversion topics that are in fact fundamental; basic to understanding not only electric machines but the electrified automobile in general. My recommendation is that readers may find some topics in parts II and III more understandable by consulting chapter 16 as needed. Others may actually wish to read over chapter 16 after Part I and before getting into electric traction drives.

 

Final Musings

My overall impression is that this book was well worth the investment, and one which I’ll proudly display on my shelve (and also available as PDF). For those wishing to dig even deeper, or for appreciation of sources, the authors provide excellent references after each chapter. In conclusion, what a great book!

Source: Bodo's Power Systems, August 2018