POWER ELECTRONICS

The aim of the course is to give the students tools to be able to analyse and understand the main circuits that are used for power electronic converters. In particular, basic knowledge of the main power electronic devices will be provided as well as advanced knowledge of electronic circuits for energy conversion in traction, transmission, and industrial/commercial applications (rectifiers, DC-DC converters, inverters). Selection and sizing of the main active devices (diodes and switches), sizing of the sinkers, analysis of the behavior and design of the power converters. Design of the passive components. Analysis and design of basic structure of feedback loops.

Knowledge and understanding

On successful completion of the module the student will be able to:

• Understand and apply the principles of power electronic converters;
• Select suitable power electronics devices and analyze their application in power electronic converters.

Applying knowledge and understanding

The students will be able to solve practical design problems and produce technical reports.

Making judgements

Ability to properly evaluate performance, electrical and thermal stresses of various power converter topologies.

Communication skills

Ability to discuss with specialists interlocutors, both on issues related the power converter and the possible solutions to be undertaken.

Learning skills

On successful completion of the module the student will be able to:

• Analyse and design standard power electronic converters;
• Select passive and active power electronic devices against a specification;
• Design and evaluate the application of power electronic converters in the conversion of the electrical energy.

Classroom Lectures on the main topics of the course. Numerical exercises on ancillary topics by the use of the personal computer and dedicated software packages. Part of the course will be devoted to laboratory sessions, where the students will learn, verify, and reinforce lecture concepts by performing switching power converter experiments.

The exam requires positive evaluation of an assigned project work in PSIM with report and presentation, followed by an oral examination.

The examination provides the opportunity for the student to demonstrate their understanding of the course material, while the project work enables students to demonstrate that they are able to apply this understanding and their analytical skills to find solutions.

Should teaching be carried out in mixed mode or remotely, it may be necessary to introduce changes with respect to previous statements, in line with the programme planned and outlined in the syllabus.

A basic understanding of electrical circuit analysis and control theory is an assumed prerequisite for this course.

Class attendance is highly recommended.

Introduction to Power Electronics. Classification of converters. Semiconductors. Solid state devices for static power converters (diode, BJT, MOSFET, IGBT, Thyristors, GTO). Static characteristics and switching behavior. Thermal behavior. Multiple connection of power devices. Driving circuits and protection circuit. Static converters. Unidirectional and bidirectional converters. Methods of analysis of the converters. Main families of static converters for electrical conversion and for applications to electric systems. Single stage and multistage converters. Outline of resonant converters. Inductors and transformers. Magnetic materials and ferrites, power losses. Copper windings, power losses due to both skin and proximity effects. Calculation of the steady-state temperature. Examples of power converter applications: home appliance, industrial, automotive, power grids, and high voltage transmission. Line-frequency converters with 12 pulses. Control of HVDC converters.

1) Ned Mohan, Tore M. Undeland. William P. Robbins, "Power Electronics: Converters, Applications, and Design". 3rd Edition, John Wiley & Sons, Inc., New York, November 2002.

2) Ned Mohan, Tore M. Undeland. William P. Robbins, “Elettronica di potenza: Convertitori e applicazioni”. Edizione italiana di Power Electronics 3rd Edition, Editore Hoepli, Milano, febbraio 2005.

3) Daniel W. Hart, “Power Electronics”, McGraw-Hill Education, January 2010.

4) Notes from the lectures.

Notes from the lectures on http://studium.unict.it/dokeos/2021/

The exam requires positive evaluation of an assigned project work in PSIM with report and presentation, followed by an oral examination.

Learning assessment may also be carried out on line, should the conditions require it.

- Explain fully the working principle of the buck converter with the help of schematic and equivalent circuit diagrams;

- Describe the main characteristics of the output voltage In a 3 phase bridge rectifier;

- Provide a detailed study of step - down dc choppers