Automotive power systems

Automotive Power Systems

Automotive Power Systems

Dorin O. Neacşu

First edition published 2021

by CRC Press

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Library of Congress Cataloging‑in‑Publication Data

Names: Neacşu, Dorin O., author.

Title: Automotive power systems / Dorin O. Neacşu.

Description: Boca Raton : CRC Press, 2020. | Includes bibliographical

references and index.

Identifiers: LCCN 2020020961 (print) | LCCN 2020020962 (ebook) | ISBN

9780367512965 (hbk) | ISBN 9781003053231 (ebk)

Subjects: LCSH: Automobiles--Electric equipment. |

Automobiles--Motors--Equipment and supplies.

Classification: LCC TL272 .N43 2020 (print) | LCC TL272 (ebook) | DDC

629.25/024--dc23

LC record available at https://lccn.loc.gov/2020020961

LC ebook record available at https://lccn.loc.gov/2020020962

ISBN: 978-0-367-51296-5 (hbk)

ISBN: 978-1-003-05323-1 (ebk)

v

Contents

Preface.................................................................................................................... xiii

About the Author ...................................................................................................xvii

Chapter 1 Architecture of an Automotive Power System.....................................1

Historical Milestones (Electricity In Cars)...........................................1

1.1 Architecture of the Automotive Power System .........................1

1.2 Voltage Used for Electrical Distribution System.......................2

1.3 Thermal Challenges for Electrical Components.......................3

1.4 Abnormal Voltages—Sources and Device Ratings...................4

1.4.1 Inductive Load..............................................................4

1.4.2 Transients on the DC Bus.............................................5

1.4.3 Reverse Voltage Protection ..........................................6

1.4.4 Mutual Coupling ..........................................................7

1.5 Requirements for the Electrical Energy System Design ...........7

1.6 Distribution of Electrical Energy ..............................................9

1.6.1 Fuses.............................................................................9

1.6.2 Cables for Automotive Applications ............................9

1.6.3 Harness Design........................................................... 10

1.7 Representation of the Electrical Circuit .................................. 12

1.8 Conclusion ............................................................................... 12

Bibliography....................................................................................... 13

Appendix #1 British Standard Colors for Cables............................... 14

Appendix #2 European Color Codes for Cables ................................ 14

Appendix #3 Popular Terminal Designation Numbers ...................... 15

Chapter 2 Batteries.............................................................................................. 17

Historical Milestones.......................................................................... 17

2.1 Functions of the Storage Battery ............................................. 17

2.2 Construction of a Lead–Acid Cell-Type Battery..................... 17

2.3 Hydrometer Readings..............................................................20

2.4 Voltage Level Test ...................................................................20

2.5 Capacity................................................................................... 21

2.6 Battery Chargers......................................................................22

2.7 Electrical Characteristics of Lead–Acid Batteries..................27

2.7.1 Internal Resistance .....................................................27

2.7.2 Efficiency....................................................................27

2.8 New Technologies for Sealed and Maintenance-Free

Batteries...................................................................................28

vi Contents

2.9 Other Possible Storage of Electrical Energy ...........................29

2.9.1 Supercapacitors ..........................................................29

2.9.2 Fuel Cell .....................................................................30

2.10 Conclusion ............................................................................... 31

References .......................................................................................... 31

Chapter 3 Starter—Alternator ............................................................................ 33

Historical Milestones.......................................................................... 33

3.1 Alternator’s Role...................................................................... 33

3.2 Construction of an Alternator..................................................34

3.3 Electronic Controls for Alternator...........................................37

3.3.1 General Requirements................................................37

3.3.2 Closed-Loop Regulation of Voltage...........................38

3.3.3 Alternator Requirements for 48 V Systems ...............39

3.3.4 Using a Switched-Mode Rectifier to Increase

Output Power..............................................................39

3.4 Other Electrical Machine Instead “Alternators” ..................... 42

3.5 Starter Systems........................................................................ 42

3.6 Starter Construction ................................................................ 45

3.7 Inertia Starter...........................................................................46

3.8 Pre-Engaged Starters............................................................... 47

3.9 Permanent Magnet Starters.....................................................48

3.10 Typical Torque Characteristics................................................48

3.11 Integrated Starter Alternator...................................................49

3.12 Conclusion ...............................................................................50

References ..........................................................................................50

Chapter 4 Body Systems ..................................................................................... 53

Historical Milestones.......................................................................... 53

4.1 Introduction to Body Systems ................................................. 53

4.2 Power Window (Electrical Windows) ..................................... 55

4.3 Power Lock Doors ................................................................... 57

4.4 Soft-Top Convertible................................................................59

4.5 Hard-Top Convertible .............................................................. 59

4.6 Power Seats..............................................................................60

4.7 Electric Sunroof....................................................................... 61

4.8 Electric Mirrors....................................................................... 61

4.9 Cruise Control ......................................................................... 62

4.9.1 Modeling the Cruise Control......................................63

4.9.2 Actuator for Cruise Control........................................64

4.9.3 Drive-by-Wire ............................................................65

4.10 Climate-Control.......................................................................66

4.10.1 Heater .........................................................................66

Contents vii

4.10.2 Electronic Heater Control ..........................................66

4.10.3 A/C Compressor......................................................... 67

4.11 Shape Memory Alloy Actuators..............................................68

4.12 Conclusion ...............................................................................69

References ..........................................................................................70

Chapter 5 Power Converters Used in Body Systems .......................................... 71

Historical Milestones.......................................................................... 71

5.1 Electrical Motors Used in Body Systems................................ 71

5.2 Integration of Power Electronics.............................................73

5.2.1 High Level of Integration...........................................73

5.2.2 Medium Level of Integration ..................................... 74

5.2.3 Low Level of Integration............................................ 75

5.3 Power Converters..................................................................... 75

5.3.1 Unidirectional dc Motor Drives ................................. 75

5.3.2 Bidirectional dc Motor Drives.................................... 75

5.3.3 Single-Phase Power Converters..................................77

5.3.4 Three-Phase Inverters ................................................79

5.3.5 PWM Generators........................................................83

5.3.6 Dead-Time..................................................................84

5.4 Integrated Circuits for Motor Control .....................................86

5.5 Sensors.....................................................................................87

5.5.1 Thermistors ................................................................87

5.5.2 Hall-Effect Position Sensor........................................87

5.5.3 Current Sensors..........................................................88

5.5.4 Voltage Measurement................................................. 91

5.6 Conclusion ............................................................................... 91

References .......................................................................................... 91

Chapter 6 Chassis Systems .................................................................................93

Historical Milestones..........................................................................94

6.1 Electrification of Transportation .............................................94

6.1.1 Introduction ................................................................94

6.1.2 Ancillary Energy Sources Derived from the

Engine.........................................................................94

6.1.3 Road to All-Electric Vehicle Concept........................95

6.2 Brake Systems .........................................................................96

6.2.1 Drum Brakes..............................................................96

6.2.2 Disk Brakes................................................................96

6.2.3 Electric Vacuum Power with a MOSFET Power

Converter....................................................................97

6.3 Electronic Control of Power Steering....................................100

6.3.1 Application ...............................................................100

6.3.2 Solution 1: An Electrical Motor Drives the Pump......101

viii Contents

6.3.3 Solution 2: Electrically Assisted Power

Steering .................................................................... 102

6.3.4 Solution 3: Principle of Electronic Power

Steering ........................................................................102

6.3.5 Dynamic Modeling of the Power Steering............... 103

6.3.6 Design With a BLDC Motor .................................... 105

6.3.7 Progressive Steering Wheel ..................................... 106

6.4 Automotive Suspension ......................................................... 107

6.5 Conclusion ............................................................................. 112

References ........................................................................................ 112

Chapter 7 Lighting ............................................................................................ 113

Historical Milestones........................................................................ 113

7.1 Automotive Light Sources..................................................... 113

7.2 Conventional Lighting Circuits ............................................. 116

7.3 Gas Discharge Lamps and Their Electronic Control ............ 119

7.4 LED Lights and Their Electronic Control............................. 122

7.5 Laser Lights........................................................................... 128

7.6 Conclusion ............................................................................. 131

References ........................................................................................ 131

Chapter 8 dc/dc Converters............................................................................... 133

Historical Milestones........................................................................ 133

8.1 Role of dc/dc Power Converters ............................................ 133

8.2 Direct Conversion (without Galvanic Isolation).................... 134

8.2.1 Buck Converter......................................................... 134

8.2.2 Boost Converter........................................................ 137

8.2.3 Other Topologies of Non-Isolated dc/dc

Converters ................................................................ 140

8.2.4 Multi-Phase Converters............................................ 141

8.2.5 The Synchronous Converter..................................... 141

8.3 Isolated Converters................................................................ 142

8.3.1 Flyback Converter .................................................... 143

8.3.2 Direct (Forward) Converter...................................... 147

8.3.3 Push–Pull Converter ................................................ 149

8.3.4 Phase-Shift Converter .............................................. 151

8.4 Auxiliary Power .................................................................... 152

8.4.1 Need for AC power................................................... 152

8.4.2 Low Power Solutions................................................ 153

8.4.3 High Power Solutions............................................... 155

8.5 Conclusion ............................................................................. 157

References ........................................................................................ 157

Contents ix

Chapter 9 Feedback Control Systems ............................................................... 159

Historical Milestones........................................................................ 159

9.1 Feedback Control of Dynamic Systems ................................ 159

9.2 Implementation within Analog-Mode Power Supply

Circuits .................................................................................. 162

9.3 Design of Feedback Control Systems.................................... 163

9.3.1 Definitions ................................................................ 163

9.3.2 Requirements for Feedback Control of a Power

Supply....................................................................... 166

9.4 Case Studies: Feedback Control for Various Power

Supplies ................................................................................. 168

9.4.1 Analog Circuit in Follower Connection ................... 169

9.4.2 Analog Circuit with an Inverting Topology ............. 171

9.4.3 Boost/Buck Converters ............................................ 173

9.5 Analog-Mode Feedback Control Solutions ........................... 174

9.5.1 Type I Compensation................................................ 175

9.5.2 Type II Compensation .............................................. 178

9.5.3 Type III Compensation............................................. 180

9.6 Design Process From Constraints to Component

Selection ................................................................................ 180

9.7 On the Use of Conventional PI/D Controllers....................... 183

9.8 Conversion of Analog Control Law to Digital Solutions ...... 185

9.9 Control System Influence on Power Electronics

Hardware ............................................................................... 188

9.10 Conclusion ............................................................................. 189

References ........................................................................................ 190

Chapter 10 Power MOSFET ............................................................................... 191

Historical Milestones........................................................................ 191

10.1 Power MOSFET in Automotive Applications ....................... 191

10.2 The Ideal Switch.................................................................... 193

10.3 Enhancement-Mode and Depletion-Mode MOSFETs .......... 195

10.4 Operation Principle ............................................................... 197

10.5 Safe Operation Area ..............................................................200

10.6 Gate Driver Requirements.....................................................202

10.7 Using P-Channel MOSFET Devices.....................................204

10.8 Parameters Used in MOSFET Selection ...............................206

10.9 Synchronous Rectification.....................................................206

10.10 Advanced FET Devices.........................................................208

10.11 Conclusion .............................................................................209

References ........................................................................................209

x Contents

Chapter 11 Fuses and Relay Circuits .................................................................. 211

Historical Milestones........................................................................ 211

11.1 Intelligent Switch Versus Solid-State Relay.......................... 211

11.2 Electromagnetic Relays ......................................................... 212

11.2.1 Using Electromagnetic Relays.................................. 212

11.2.2 Construction ............................................................. 214

11.3 Solid-State Relays.................................................................. 216

11.4 Introduction to Fuses............................................................. 219

11.5 Circuit Breakers.....................................................................223

11.6 Automotive Varistor and Transient-Voltage-

Suppression (TVS).................................................................223

11.7 Solenoids................................................................................225

11.7.1 Electromechanical Solenoid.....................................225

11.7.2 Solenoid Valve..........................................................226

11.7.3 Power Converter Drive.............................................228

11.8 Conclusion .............................................................................228

References ........................................................................................228

Chapter 12 Small Motors.................................................................................... 231

Historical Milestones........................................................................ 231

12.1 Principle of Electrical Motors ............................................... 231

12.1.1 Permanent Magnet Motors....................................... 231

12.1.2 Variable Reluctance Motor....................................... 232

12.1.3 DC Motors................................................................234

12.1.4 Induction Motor........................................................ 235

12.1.5 Brushless Motors......................................................236

12.1.6 Comparison between Brushless dc Motor and the

Induction Motor........................................................240

12.2 Design of Low-Power dc Motors...........................................242

12.2.1 Shunt-Wound dc Motors...........................................242

12.2.2 Series-Wound dc Motors..........................................243

12.2.3 Compound Wound dc Motor....................................243

12.2.4 Permanent Magnet dc Motors ..................................244

12.3 Applications: Fans, Blowers, Pumps.....................................245

12.4 Design Issues Related to the dc Distribution Bus..................247

12.5 Motor Design: Inertia Matching............................................248

12.6 Motor Design: Torque Requirements ....................................249

12.7 Ultrasonic Motors (Piezoelectric Motors)............................. 251

12.7.1 Principle ................................................................... 251

12.7.2 Control and Optimization ........................................ 253

12.8 Conclusion .............................................................................254

References ........................................................................................254

Contents xi

Chapter 13 Power Integrated Circuits................................................................. 255

Historical Milestones........................................................................ 255

13.1 Integrated-Circuit Technologies............................................256

13.2 Architecture of Analog or Mixed-Mode Power IC ............... 257

13.2.1 Example of Disruptive Innovation—PWM

Control Chip............................................................. 257

13.2.2 Flyback PWM Controller IC for Isolated Power

Supplies....................................................................259

13.2.3 Three-Phase Power MOSFET Controller ................260

13.2.4 High-Voltage Gate Drivers for High-Voltage

Propulsion Drives.....................................................260

13.3 IC Design Considerations......................................................262

13.3.1 Power MOSFET Used within Integrated

Circuits..................................................................... 262

13.3.2 Power Diode .............................................................264

13.3.3 Gate Driver...............................................................265

13.3.4 Band Gap Reference.................................................266

13.3.5 PWM Generator .......................................................266

13.3.6 Current Sensor..........................................................266

13.3.7 Auxiliary Protection Circuitry.................................268

13.3.8 Soft-Start Circuitry...................................................269

13.3.9 I/O Connections .......................................................269

13.4 Digital IC Solutions ............................................................... 270

13.5 Conclusion ............................................................................. 270

References ........................................................................................ 271

Chapter 14 Propulsion Systems .......................................................................... 273

Historical Milestones........................................................................ 273

14.1 Propulsion Architecture ........................................................ 273

14.2 Induction Motor Drive—Converter System.......................... 276

14.3 Brushless dc Motor Drive......................................................283

14.4 Switched Reluctance Motor Drive.........................................285

14.5 High-Voltage Energy Storage ................................................288

14.6 Conclusion .............................................................................289

References ........................................................................................290

Index...................................................................................................................... 291

xiii

Preface

Vehicles are intrinsically linked to our lives. Since we have entered the new mil￾lennium, the expectations for comfort and safety in our vehicles are continuously

rising. Meeting these expectations asks for more controllability of vehicle sub-sys￾tems, which can only be achieved with microcontroller software. In the software, the

designer can include optimal features, treat case-based operation, or adapt to various

conditions, all while employing the same electromechanical hardware. Electronics

and software engineering applied to vehicle systems are the flashpoint for technologi￾cal, economic, and social innovation, fueling imagination and technical debate, from

elbow-deep laboratory experimentation to abbreviation-rich marketing meetings.

Starting in 1991, carmakers began to include more electronics to advance the

performance of their vehicles. It began when California required all cars sold in

the state to feature a self-diagnostic ability. By 1996, the US Federal government

extended the requirement for all cars to include a standard port to connect to for

system diagnosis. Technologies like Bluetooth, GPS, blind-spot detection, collision

warning systems, and adaptive cruise control followed enthusiastically. The average

vehicle today has numerous microcontrollers that help control a variety of functions

for added comfort and safety operation. All this created a market for automotive

semiconductors that is worth $36 billion.

The common assertion for electronics engineering used in vehicle calls for elec￾tric and hybrid vehicle technologies. Despite a huge media and regulatory presence,

the electric vehicle has entered slowly into the mainstream market, with a tiny share

of only about 1% of vehicle sales globally. Although manufacturing and selling elec￾tric vehicles help to comply with regulations, the money is made with engine tech￾nologies that have been around for over a century.

Meanwhile, without a comparable media or social presence, the process of vehicle

electrification is more appealing to the young electronics engineer due to a sizeable

employability market. Vehicle electrification aims to replace or improve numerous

mechanical convenience systems with electrically actuated systems, while maintain￾ing the engine technology for propulsion. Examples include applications for both

chassis and body systems.

Collectively known as body electronics, comfort and convenience systems allow

vehicle occupants to feel comfortable and safe inside the vehicle. Examples include

power windows, soft-convertible systems, hard-convertible systems, power door

locks, power seats, electric steps, electric mirrors, electric sunroof, auto-dimming

rearview interior and side mirrors, remote keyless entry, power trunk or lift-gate

systems. Each such gimmick requires one or more dc motors with either a simple on/

off control or through communication with other features.

The chassis designates the complete car, less the body, and consists of the engine,

power-transmission system, and suspension system. These systems are attached

to a structurally independent frame. Electrification is herein achieved with power

electronic converters used in brake systems, in steering systems, and in suspension

systems.

xiv Preface

The main challenge in vehicle electrification consists of replacing the engine￾based mechanical, pneumatical, or hydraulic energy source with electrical energy

through an electromagnetic device. Obviously, this raises other issues with the size

and technology of the battery bank and its ability to accommodate the new load

demands coming with electrification.

The two major processes of electrical propulsion and electrification are converg￾ing to create the all-electric vehicle. Unless man-made gas takes off and maintains

a competitive combustion engine solution, built on long-established value chains,

electric vehicles will become the norm in the future.

This book attempts to cover all the details of the electrification process, with a

focus on the electronics and power electronics used within modern vehicles. It is

aimed at young engineers in need of an introductory class in automotive power elec￾tronics. The book structure follows the architecture of the conventional engine-based

vehicle, with the last chapter dedicated to an introduction into electric propulsion.

Everything is described at an introductory level, yet covers all details from the com￾ponents to system architecture.

The key component in both electrification and electric propulsion processes is pro￾vided by power electronics. Power electronics deals with the electronic processing of

energy. This makes it a support technology for the automotive industry. All the auto￾motive visions for the next decade (2020–2030) are built on top of power electronics.

According to a recent report from the McKinsey Corporation (Ondrej Burkacky,

Jan Paul Stein, Johannes Deichmann, “Automotive software and electronics 2030 -

Mapping the sector’s future landscape”), the power electronics industry associated to

the automotive sector is expected to increase 15% CAGR (compound annual growth

rate), which is the highest for a decade among all automotive technologies.

Since this expectation brings its own particulars, specific topologies, design prac￾tices, software control, or usage habits, it deserves to have a dedicated textbook for

such a major application field.

The first part of the book describes the automotive applications at a system level,

involving power electronics, with numerous examples. The second part explores fur￾ther details of each component and can be seen as a brief course in basic power elec￾tronics, motor drives, or electrical material technologies. The author considers that

the reader needs to first fully comprehend the core task, before tackling the power

electronics solution.

Since young specialists in automotive power electronics systems are faced with

more than building power electronics hardware, the book attempts a brief introduc￾tion to topics ranging from materials used in electrical circuits to control systems

implemented in software controlling power converters.

Examples for the mathematical modeling of mechanical systems within a vehicle

are presented in “Sections 4.9 Cruise control”, “6.4. Automotive suspension”, “6.3.

Electronic Control of Power Steering” and “12.7. Ultrasonic motors”.

Mathematical models are also presented for dc/dc power converters for either

analog or digital implementation. Principles for the design of feedback control sys￾tems for dc/dc power converters are elaborated in a dedicated chapter based on math￾ematical models.