34623 - Electrical Propulsion Systems M

Course Unit Page

  • Teacher Claudio Rossi

  • Credits 6

  • SSD ING-IND/32

  • Language Italian

Academic Year 2018/2019

Learning outcomes

·         Configurations of full-electric drivetrain for road vehicles

·         Unified method for analyzing the mechanical and electrical characteristics of electric drive suitable for traction applications

·         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

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

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


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     Contribution to the momentum due to wheels, transmission, shafts, rotors, vehicle mass, load     Aerodynamic load force     Friction and weight load force     traction and wheel slipage     example data set for different vehicle categories (small passenger car, SUV, etc…)     implementation of a complete Simulink vehicle load model

1.2.2    More dynamic vehicle characteristics (briefly)  Pitch, Yaw, Roll     Vehicle stability, drift


1.4          Mechanical Transmissions

1.4.1      Transmission with discrete gear ratios     H gearbox   Dual clutch, sequential gearbox.

1.4.2    Epicycloidal gear set     Layout and principle of operation     Kinematic. Willis equation     Power and torque sharing     Dynamic equations     Efficiency     Complete model of the epycicloidal gear set     Application of the epycicloidal gear set     Differential gearbox

1.4.3      Automatic gearboxes (brief)     Pulley-based CVTs     Torque converter based on the epycicloidal gear set

1.5          Components o fan electric drive train

 1.5.1    Full electric drivetrain. Basic schemes.


1.5.2     Electric machines    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.    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.    Direct-drive solutions. Sizing of a brushless SPM-SM. Operating limits. Mechanical integration issues.    High-speed machines. Sizing of a brushless SPM-SM. Operating limits. Reduction gearbox.


1.5.3    Inverter     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.    DC bus. Current components on the DC-bus. Sizing criteria for the DC bus capacitance. Capacitor technologies.    Control system. Architecture of a microprocessor based control board for electric traction drive system. Auxiliary circuits


1.5.4      Storage systems     Review of the possible storage systems suitable to be applied to electric traction. Ragone diagram.    Lead batteries. Electrochemical reaction. Type (lead-acid, VRLA, ecc.). Main technological drawbacks.    Ion-Lithium and Lithium polimer batteries. Electrochemical reaction. Characteristics and main technological drawbacks.    Model of a electrochemical energy storage system. SOC estimation      Cells equalization. Active and passive equalization schemes.    High power density energy storage systems: supercapacitors, flywheel. Characteristics. Models.


1.6 Hybrid drivetrains

1.6.1    Full-hybrid transmissions    Series hybrid drivelins. Scheme. Components sizing.   Power split e-CVT of ‘input' and ‘compound' type. Toyota, Ford, Mercedes – GM solutions    Advanced power split e-CVT solutions

1.6.2    Mild-hybrid and mini-hybrid solutions


1.7 Standards  SAE standards for electric vehicles  Safety Integrity Level (SIL). IEC 61508 e IEC 61511  Homologation regulation    Standards for recharge of electric vehicles  (EN 61851)   


Vehicles – case studies

1.8.1    Vehicle classification

1.8.2    Analysis of the main issues related to the sizing of the powertrain for the following vehicles: Electric bicycle Electric scooter  Quadricycle  Car (M1) Light-duty  truck (payload <3.5ton)  Urban bus


Title:     Propulsion Systems for Hybrid Vehicles

Author:         John M. Miller 

Publisher:  Institution of Engineering and Technology

Edition:    2a edition (June 30, 2010)

Series:     Iet Renewable Energy


ISBN-10:  1849191476

Teaching methods

50% classes 50% computer assisted modelling

Assessment methods

presentation of a final work constituted by a powertrain design  oral exam

Teaching tools

slides  mathematical models

Office hours

See the website of Claudio Rossi