This course aims to provide an extensive know-how about typical modeling techniques applied to IC engines (both spark ignition and compression ignition) and hybrid/electric powertrains, in order to predict the efficiency of on-board energy conversion process and the related pollutant emissions, as function of different architectures (IC engine, hybrid series/parallel, plug-in, full electric vehicle).

The course provides experience with IC engine and hybrid/electric vehicle modeling tools. Simulation codes are applied to build up integrated models of the various components. A numerical laboratory is included to allow a direct application of a few simulation tool

Power electronics and electrical machines applied to series/parallel hybrid vehicles are analyzed, as for their structure, performance, dynamical modelling and simulation. The thermal behavior will be studied too. Simulation will be applied to normal and peculiar operating conditions, like the regenerative braking.

After completing the course students will be able to:

• understand the modeling approaches and numerical techniques adopted to simulate the most important processes in IC engines, power electronics, electrical machines and hybrid vehicles;
• evaluate all relevant parameters of automotive propulsion systems, taking into account the vehicle architecture, operation and interaction among different components;
• assess the advantages/disadvantages of each solution in terms of performances, pollutant and CO2 emissions, flexibility, range;
• have knowledge about the potential and field of application of simulation tools for IC engine performance and emissions and for power electronics and electrical machines;
• have a good familiarity with the use of 0D/1D thermo-fluid dynamic tools and simplified vehicle simulation tools for a preliminary analysis of automotive propulsion systems.

1D simulation of intake and exhaust systems by fluid dynamic models: prediction of unsteady flows; fundamental equations and numerical methods; boundary conditions

Single zone and multi-zone thermodynamic combustion models: SI and CI engines; balance equations, solution methods; chemical equilibrium and simplified kinetic sub-models.

Prediction of typical pollutant emissions from SI and CI engines: CO, HC, NOx, soot, by means of suitable kinetic sub-models and simplified semi-empirical models.

Conversion of pollutants in after-treatment systems: modeling of chemical reactions and conversion efficiency of three-way catalyst, SCR, oxidation catalyst, DPF.

Conventional/hybrid vehicle simulations under real driving conditions: calculation of performances (engine efficiency, fuel consumption and CO2 emission) and emissions, considering different vehicle architectures.

Power Electronics and converters: Description of the characteristics of diodes and controllable switches (Mosfets, IGBTs, …) and thermal behaviour. Switch mode dc-dc converters: full-bridge (four quadrant) converter. PWM modulation. Switch mode dc-ac converters: single phase and three-phase structure. Sinusoidal PWM modulation.

Electrical Machines for traction: Rotating magnetic field. Synchronous machine. Permanent Magnets Brushless DC and AC: structure, operation principle, mechanical characteristic. Induction machine. Structure, operation principle, mechanical characteristic. Synchronous Permanent Magnet Outer Rotor (In-Wheel) Motor.

Modelling of a bidirectional DC–DC converter for electric vehicle driving system.

Modelling and simulation of a series hybrid vehicle from the electrical viewpoint.

Modelling of the regenerative braking systems.

Storage batteries and electrical charging of a vehicle.

Notions of IC engines from the MSc level; notions of thermodynamics, chemistry and fluid machines from the BSc level. Principles of electrical engineering.

Evaluations at all official exam dates will consist of a written exam including:

• a first part with 10 multiple-choice questions on fundamental theoretical topics;
• a second part with open theoretical and numerical questions.

A facultative oral discussion is available to complete the exam for the highest marks (≥28) and not foreseen in all other cases.

The student during the examination must demonstrate:

• to have the ability to organize the knowledge of the different topics of the course and the interrelations existing between them;
• to have the capacity for critical reasoning on the theoretical concepts that led to the definition of the different technological solutions which have been studied;
• to be able to quantitatively determine the main geometrical and operational parameters which are asked in the proposed numerical exercises;
• to describe each topic with good technical language and adequate synthesis and linearity.