86475 - Electric Propulsion Systems

Academic Year 2023/2024

  • Docente: Claudio Rossi
  • Credits: 6
  • SSD: ING-IND/32
  • Language: English

Learning outcomes

In this course students: 1. Learn a method for analyzing electric drives, used for studying the integration of electric systems into the traction system of a road vehicle. 2. Learn the main subjects related to the management of electric drives supplied by battery packs. 3. Learn how to manage more than one electric drives in the same energetic conversion system. 4. Learn design methodology for full electric and hybrid-electric propulsion system and sizing criteria for the main components. 5. Develop the ability to model a full traction system, composed of: electric drives, battery system, transmission, vehicle longitudinal dynamic, including the control system 6. Develop the ability to analyze uncommon powertrain configurations both in terms of topology and basic technology.

Course contents


Expectation and role played by ‘powertrain electrification’ for the reduction of pollutant emission and for increasing the efficiency of road vehicles.

Road vehicle classification as a function of the hybridization level of the powertrain.

Vector control of AC brushless machines

Introduction to Clarke and Park coordinate transformation. Equation of sinusoidal brushless machine. Reluctance torque. Basic control scheme.

Unified method for AC drives analysis

Three-phase AC machines suitable to be used for traction application.

Unified and normalized method for representing the operating point and operational limit of three-phase AC machines operating in field oriented control.

Comparison among mechanical and electrical characteristics of brushless machines of the following types:

  • SPM-SM (Surface Permanent Magnet – Synch. M.),
  • IPM-SM (Internal Permanent Magnet – Synch. M.)
  • VIPM-SM (V-shape Internal Permanent Magnet – Synch. M.)
  • RIPM-SM (Radial arranged Internal Permanent Magnet – Synch. M.)
  • PMAR-SM (Permanent Magnet Reluctance Assisted– – Synch. M.).

All the drives will be detailed analyze in the whole operating range, with reference to overload and speed greater then nominal.

Efficiency maps in the whole operating range of the machines.

Extension of the unified method to wound rotor synchronous machines (WRSM) and induction machines (IM).

Operation of brushless machines in Uncontrolled Generation operation (UCG). Safety issues.

Differences of mode of operation of electric drives in motoring and generating mode.

Hybrid propulsion systems

Classification of hybrid configuration (series, parallel, power-split)

Principle of operation and design criteria for a passenger car power-split e-CVT transmission.. Selection and sizing methods for the electric drives installed within the power-split e-CVT transmission.

Standards and safety

Functional safety of an electrical powertrain, with reference to Automotive Safety Integrity level (SIL), IEC 61511.

AC and DC conductive charging of electric vehicle(EN 61851).

Technology survey

Review of technology for power converters in relation to power and voltage range.

Application of electric drives outside of the powertrain. For example: HVAC, power steering.

Electric drive technology readiness level for full electric and hybrid powertrain.

Trends and opportunities for electric drives in the automotive sector.


For study:

The didactic material distributed by the teacher: copy of slides, files and description of the used numerical models.

For deepening the course contents:

Iqbal Husain “Electric and Hybrid Vehicles: Design Fundamentals”, Second Edition. CRC Press. ISBN 9781439811757

Teaching methods

The course includes: theoretical lectures made with the aid of multimedia systems. The didactic material is uploaded before each lecture

Training and laboratory activities related to the realization of numerical model of a complete electric traction system combined with the longitudinal dynamic model of a vehicle.

Assessment methods

The exam includes both a project development and an oral test.

The project consists of the development of an electric or hybrid traction system for a road vehicle, using numerical simulation tools introduced during training activity. The text of the project will be delivered to students during classes and will be presented at the final exam.

The oral test is composed by two parts: 1) presentation of the developed project and validation of the obtained results. 2) testing the knowledge of the theoretical course content.

Teaching tools

Modelling environment based on Matlab and Simulink

Office hours

See the website of Claudio Rossi


Sustainable cities Responsible consumption and production

This teaching activity contributes to the achievement of the Sustainable Development Goals of the UN 2030 Agenda.