Power Electronics Converters

Course description

Nowadays, study of power electronics is not focused only on the generally known criteria list the power converters should comply with: loss reduction, increase of their specific power, estimation of their useful lifetime and the production cost. Increasingly important is to understand their roles in connecting complex systems for the efficient conversion of energy from renewable sources in electricity and its further efficient conversion and end-use in systems such as: smart heating/cooling, hybrid vehicles, smart grids.

Detailed content:

1) Insights into modern solid-state power switches and the challenges they face e.g. heat dissipation and reduction of parasitic inductances. Overview of main challenges and study of specific attempts in integration of the converter components into a unified whole (systemically and geometrically). Study of mechanisms of excess heat dispersal, reduction of mutual electromagnetic influence, achieving an appropriate dielectric strength and reliability.

2) Practical design issues, such as snubbers, semiconductor stresses due to the high slope of current and voltage, losses and efficiency.

3) Review of basic modulations (PWM, vector control and others) and related solutions specific to the operation near to the margins (in terms of low duty cycle) of existing semiconductor switches. Various control of semiconductor converters. Predictive and repetitive control methods in power electronics.

4) Effects of power converters to the supply grid voltage and to the adjacent electronic devices. Study of electromagnetic compatibility problems: sources of electromagnetic (EM) emissions, modes of coupling and reduction techniques of EM emissions. Setups for measuring radiated and conducted emissions.

5) Overview and analysis of modern designs in the case of specific converter topologies (serial / parallel multi-cell converter design, serial / parallel connection of power switches, combining different modes of operation).

6) System-oriented analysis of operating conditions, stability conditions in selected state of the art converter systems and sub-systems.

Performing sensitivity analysis to assure various control and power flow aspects (distortion, resonance mitigation).

 

Course is carried out on study programme

Objectives and competences

Objectives: To promote in-depth understanding of the operation, technological and material constraints and the integration of modern inverters power in the wider scientific context. To encourage the cutting-edge design procedures and technologies pursuit. Strengthen awareness of the effects of connecting multi-cell converters and distributed ones in the event of their central control management.

Competencies: Upgrading the basic knowledge in the field of power electronics and control engineering. Gain competences with knowledge of complementary technical branches.

Learning and teaching methods

Lecture and consultation hours – to assist and lead candidate through his/her homework assignment.

Intended learning outcomes

In-depth understanding of the converters operation and their physical limitations.

To gain knowledge for deeper analysis and design steps in solving specific problems of power electronic converters. The ability to perform system-oriented evaluation and analysis.

Reference nosilca

1. Petkovšek M, Leban A, Nemec M, Vončina D, Zajec P (2013) Series active power filter for high-voltage synchronous generators. Informacije MIDEM, vol. 43, no. 4:228-234

2. Flisar U, Vončina D, Zajec P (2012) Voltage sag independent operation of induction motor based on Z-source inverter. Compel, vol. 31, no. 6:1931-1944

3. Rupar U, Lahajnar F, Zajec P (2012) Iterative-learning-based torque-ripple compensation in a transverse flux motor. IET control theory & applications, vol. 6, no. 3:341-348

4. Petkovšek M, Kosmatin P, Zevnik C, Vončina D, Zajec P (2012) Measurement system for testing of bipolar plates for PEM electrolyzers. Informacije MIDEM, vol. 42, no. 1:60-67

5. Ostrožnik S, Bajec P, Zajec P (2010) A study of a hybrid filter. IEEE transactions on industrial electronics, vol. 57, no. 3:935-942

Study materials

  1. Bose BK (2010) Power Electronics And Motor Drives: Advances and Trends. Academic Press, London
  2. Strzelecki R, Benysek G (2008) Power Electronics in Smart Electrical Energy Networks. Springer, London
  3. Orłowska-Kowalska T, Blaabjerg F, Rodríguez J (2014) Advanced and Intelligent Control in Power Electronics and Drives. Springer, New York
  4. Fuchs E, Masoum MAS (2011) Power Quality in Power Systems and Electrical Machines. Academic Press, London

Bodi na tekočem

Univerza v Ljubljani, Fakulteta za elektrotehniko, Tržaška cesta 25, 1000 Ljubljana

E:  dekanat@fe.uni-lj.si T:  01 4768 411