Page 8 - Power Electronic Control in Electrical Systems

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xii Preface

Chapter 3 reviews the principles of transmission system compensation including
shunt and series compensation and the behaviour of long transmission lines and cables.
Chapter 4 addresses the mathematical modelling of the electrical power network
suitable for steady state analysis. Emphasis is placed on the modelling of plant
components used to control active and reactive power flows, voltage magnitude
and network impedance in high-voltage transmission. The model of the power net-
work is the classical non-linear model, based on voltage-dependent nodal power
equations and solved by iteration using the Newton±Raphson method. The basic
method is then expanded to encompass the models of the new generation of power
systems controllers. The new models are simple and yet comprehensive.
Chapter 5 introduces the power semiconductor devices and their characteristics as
part of a power electronic system. It discusses the desired characteristics to be found
in an ideal switch and provides information on components, power semiconductor
device protection, hardware issues of converters and future trends.
Chapter 6 covers in detail the thyristor-based power electronic equipment used in
power systems for reactive power control. It provides essential background theory to
understand its principle of operation and basic analytical expression for assessing its
switching behaviour. It then presents basic power electronic equipment built with
voltage-source converters. These include single-phase and three-phase circuits along
with square wave and pulse-width modulation control. It discusses the basic concepts of
multilevel converters, which are used in high power electronic equipment. Energy stor-
age systems based on superconducting material and uninterruptible power supplies are
also presented. Towards the end of the chapter, conventional HVDC systems along
with VSC-based HVDC and active filtering equipment are also presented.
Chapter 7 deals with the all-important topic of power systems harmonics. To a
greater or lesser extent all power electronic controllers generate harmonic currents,
but from the operator's perspective, and the end-user, these are parasitic or nuisance
effects. The book addresses the issue of power systems harmonics with emphasis on
electronic compensation.
Chapter 8 provides basic information on how the industry standard software
package PSCAD/EMTDC can be used to simulate and study not only the periodic
steady state response of power electronic equipment but also their transient response.
Specifically, detailed simulation examples are presented of the Static Var compensa-
tor, thyristor controlled series compensator, STATCOM, solid-state transfer switch,
DVR and shunt-connected active filters based on the VSC concept.
Dr Acha would like to acknowledge assistance received from Dr Claudio R.
Fuerte-Esquivel and Dr Hugo Ambriz-Perez in Chapter 4. Dr Agelidis wishes to
acknowledge the editorial assistance of Ms B.G. Weppler received for Chapters 5 and
6. Mr Anaya-Lara would like to express his gratitude to Mr Manual Madrigal for his
assistance in the preparation of thyristor-controlled series compensator simulations
and analysis in Chapter 8.

Enrique Acha
Vassilios G. Agelidis
Olimpo Anaya-Lara
Tim Miller