34623 - Electrical Propulsion Systems M

Learning outcomes

·         Configurations of full-electric drivetrain for road vehicles

·         Main configurations of hybrid drivetrain for road vehicles. Hybrid solutions: series, parallel, power split.

·         Control issues in electric and hybrid drive trains. Technological limits of the basic components (electric machines, drive systems, mechanical transmission, energy storage systems).

·         Main features and limits of electrochemical storage system

·         Design method for an electric and a hybrid drivetrain, and components sizing

·         Solutions for hybrid ship propulsion

Course contents

1             Electric traction systems for road vehicles

1.1          Course introduction

1.1.1      How to save fuel for saving money

1.1.2      More electric vehicles: a step forward a sustainable mobility.

1.2          Dynamic model of a road vehicle

1.2.1      Equation of longitudinal motion of a vehicle

1.2.1.1     Contribution to the momentum due to wheels, transmission, shafts, rotors, vehicle mass, load

1.2.1.2     Aerodynamic load force

1.2.1.3     Friction and weight load force

1.2.1.4     traction and wheel slipage

1.2.1.6     example data set for different vehicle categories (small passenger car, SUV, etc…)

1.2.1.7     implementation of a complete Simulink vehicle load model

1.2.2    More dynamic vehicle characteristics (briefly)

1.2.2.1  Pitch, Yaw, Roll

1.2.2.2     Vehicle stability, drift

1.3      Thermal engines (brief description)

1.3.1 Principle of operation. Layouts

1.3.1.1 Brief description of Diesel, Sabathè, Atkinson cycles

1.3.1.2     p-v diagrams

1.3.2    Output mechanical caracteristic of a thermal engine

1.3.2.1     MEP-Mean Effective Pressure. Engine torque

1.3.2.2  BSFC – Brake Specific Fuel Consumption

1.3.2.3  Engine diagrams: torque, speed, BSFC.

1.3.2.4  Minimum consumption operating points. Example diagrams

 

1.4          Transmissions

1.4.1      Transmission with discrete gear ratios

1.4.1.1     H gearbox

1.4.1.2   Dual clutch, sequential gearbox.

1.4.2    Epicycloidal gear set

1.4.2.1     Layout and principle of operation

1.4.2.2     Kinematic. Willis equation

1.4.2.3     Power and torque sharing

1.4.2.4     Dynamic equations

1.4.2.5     Efficiency

1.4.2.6     Complete model of the epycicloidal gear set

1.4.2.7     Application of the epycicloidal gear set

1.4.2.8     Differential gearbox

1.4.2.8     Differential gearbox

1.4.3      Automatic gearboxes (brief)

1.4.3.1     Pulley-based CVTs

1.4.3.2     Torque converter based on the epycicloidal gear set

1.5          Electric drive train components

 1.5.1    Full electric drivetrain. Basic schemes.

1.5.2     Electric machines

1.5.2.1    Synchronous brushless motor. Classification. Main characteristics. Numerical model of a brushless drive system suitable for electric traction. Operating regions: MTC, overload, high speed. Control scheme. Main issue regarding the use of this machine on electric drivetrains. Efficiency maps.

1.5.2.2    induction motor. Classification. Main characteristics. Numerical model of an induction drive system suitable for electric traction. Operating regions: MTC, overload, high speed. Control scheme. Main issue regarding the use of this machine on electric drivetrains. Efficiency maps.

1.5.2.3    Direct-drive solutions. Sizing of a brushless SPM-SM. Operating limits. Mechanical integration issues.

1.5.2.4    High-speed machines. Sizing of a brushless SPM-SM. Operating limits. Reduction gearbox.

1.5.3    Inverter

1.5.3.1     Power stage. Two level solution. Power devices (Mosfets, IGBT). Assembly technologies. Power density VA/cm3 and VA/€ as a function of power and voltage rating.

1.5.3.2    DC bus. Current components on the DC-bus. Sizing criteria for the DC bus capacitance. Capacitor technologies.

1.5.3.3    Control system. Architecture of a microprocessor based control board for electric traction drive system. Auxiliary circuits

1.5.4      Storage systems

1.5.4.1     Review of the possible storage systems suitable to be applied to electric traction. Ragone diagram.

1.5.4.2    Lead batteries. Electrochemical reaction. Type (lead-acid, VRLA, ecc.). Main technological drawbacks.

1.5.4.3    Ion-Lithium and Lithium polimer batteries. Electrochemical reaction. Characteristics and main technological drawbacks.

1.5.4.4    Model of a electrochemical energy storage system. SOC estimation

1.5.4.5      Cells equalization. Active and passive equalization schemes.

1.5.4.6    High power density energy storage systems: supercapacitors, flywheel. Characteristics. Models.

1.6 Hybrid drivetrains

1.6.1    Full-hybrid transmissions

1.6.1.1    Series hybrid drivelins. Scheme. Components sizing.

1.6.1.2   Power split e-CVT of ‘input' and ‘compound' type. Toyota, Ford, Mercedes – GM solutions

1.6.1.3    Advanced power split e-CVT solutions

1.6.2    Mild-hybrid and mini-hybrid solutions

 

Readings/Bibliography

Modern electric, hybrid electric, and fuel cell vehicles : fundamentals, theory, and design /
Mehrdad Ehsani ... [et al.]. - Boca Raton : CRC, c2005.
http://www.engnetbase.com/books/4675/3154fm.pdf. -
ISBN 0849331544

Propulsion systems for hybrid vehicles
John M. Miller.
Stevenage : IEE, c2004. - XVI, 455 p.
ISBN 0863413366

Assessment methods

Discussion about a design report of an electric traction system
Oral exam

Teaching tools

Laboratory activity for the realization of models of vehicles, components and complete traction systems.

Office hours

See the website of Claudio Rossi