ENGINEERING TRIPOS PART IIA - 2012/2013

Module 3B3
Switch-Mode Electronics

Leader: Dr R. McMahon

2 lectures/week, Michaelmas (Dr R. McMahon).

AIMS

Introduce power electronics as an interface technology. Introduce power semiconductor devices and circuits, describing their use in a range of applications. These include rectification, linear and switch-mode power supplies, a.c. power control circuits and dc-ac inverters using pulse-width modulation.

SYLLABUS:

• The diode; simple rectifier circuits using diodes. Three-phase rectification. Smoothing circuits and waveform distortion. Regulated supplies using linear circuit techniques.
• The thyristor. Controlled rectification and inversion using thyristors.
• The MOSFET, IGBT and bipolar transistor as power switches.
• Basic switching converter configurations: the up and down converters. The concept of pulse width modulation; the generation of pulse-width modulated waveforms. Converters with isolation. Introduction to magnetics and components.
• Power losses in converters. ZCS and ZVS Resonant converters.
• Outline design for a complete switch-mode power supply including power factor correction.
• Half and full bridge circuits, Deadtime and the problem of the high side drive. The application of chopper circuits in DC motor drives.
• Single phase and three-phase invertercircuits. Variable voltage variable frequency three-phase inverter for use in induction motor drives.
• Transient Analysis in circuits.

OBJECTIVES

On completion of the course students should;-

• Know the characteristics of the diode and how to use diodes in rectifier circuits to obtain d.c. from single and three-phase a.c.
• Know how to reduce ripple using smoothing circuits.
• Know the characteristics of the thyristor and how to use the thyristor in controlled rectifiers operating from single or three-phase supplies.
• Be able to explain the conditions under which inversion, i.e. the flow of power from the d.c. to the a.c. side, takes place.
• Appreciate the relative merits of MOSFETs, IGBTs and bipolar transistors as switches.
• Be aware of the principal types of converter circuit and their characteristics.
• Know the principle of pulse-width modulation and simple ways of generating pulse-width modulated waveforms.
• Be familiar with three-phase inverter circuits using pulse-width modulation.
• Be familiar with the essential elements of a complete switch-mode power supply.
• Be able to analyse the operation of a simple SMPS.
• Describe the various losses and estimate the efficiency of a Power Electronic System.
• Appreciate the role of power electronic converters in various applications.

REFERENCES

Please see the Booklist for Part IIA Courses for references for this module.