Modern Power Supplies

Subject description

Introduction to high frequency switching converters, basic converter types and overview of basic terminology; Quasi-stationary operation of DC / DC converters (analysis of Vs and As equilibrium, circuit gain, output ripple); Introduction to open-loop and closed-loop procedures for controlling the converter (PWM, phase-shift PWM, DTM, hysteresis controller); Addressing the low-signal model of the DC / DC converter (transfer function, continuous and discontinuous current mode operation); Introduction to basic components (power transistors, driver and snubber circuits) and addressing the procedures for their design; Introduction to DC / AC converters for electric motor drives and for use in uninterruptible power supply systems (UPS) and photovoltaic systems (performance analysis, modulation principles, harmonic spectrum); Addressing the feedback effects of devices on the voltage source and burden (active and passive filtering measures, output quality factors); Addressing the basic concepts of electromagnetic compatibility (sources and methods of dissemination of interference) and measures (design of converters' PCB, selection criteria and calculation of electronic components) in order to reduce EM imitations.

The subject is taught in programs

Objectives and competences

The objective of the course is to provide the student with knowledge about devices that convert electricity with high switching frequencies. The student learns the topology of devices and associated subunits, which are necessary for reliable and safe operation. The subject gives a more detailed insight into the operation and knowledge for designing switching power supply systems from the proper choice of power components to their optimization. The student learns about the basic procedures and the validity of simplifications taken during mathematical modelling, the importance of the parasitics of the embedded components, and the measures for eliminating and reducing the feedback effects on the surroundings of the conversion devices.

Teaching and learning methods

Lectures, exercises, guided project work. Part of the pedagogical process will be carried out with the help of ICT technologies and the opportunities they offer.

Expected study results

After successful completion of the course, students should be able to:

develop a mathematical (steadystate and small-signal) model for the DC/DC and DC/AC converter,
describe the main components’ role,
analyse the operation of the converter on the basis of the measured currents and voltages,
calculate the current, voltage and power stress for each component,
explain the influence of parasitic inductance and capacitance of components on the operation of the converter,
argue the countermeasures for elimination or reduction of the converters’ feedback effects on the voltage source, burden and adjacent devices.

Basic sources and literature

M. Milanovič: Uvod v močnostno elektroniko, učbenik, Univerza v Mariboru, Fakulteta za Elektrotehniko računalništvo in informatiko, Maribor, 1997.
P. Zajec: Interna skripta, Univerza v Ljubljani, Fakulteta za Elektrotehniko.
B. K. Bose, Power Electronics And Motor Drives: Advances and Trends. Academic Press, 2010.
J. Jacob, Power Electronics: Principles and Applications. Cengage Learning, 2001.
T. L. Skvarenina, The Power Electronics Handbook. CRC Press, 2001.
T. Williams, EMC for Product Designers. Elsevier Science, 2011.