POWER ELECTRONICS

Power electronics is the enabling technology of the modern electrified world. Every time a laptop charger converts mains voltage into a clean five-volt supply, every time an electric vehicle accelerates smoothly onto a motorway, and every time a wind turbine delivers synchronised power to the grid, a power-electronic converter is silently doing its work. The discipline sits at the intersection of electrical machines, semiconductor physics, control theory, magnetics, and thermal management, and it is precisely this breadth that makes it both challenging and endlessly rewarding to study.
This book grew out of many years of teaching undergraduate and postgraduate courses in power electronics and electric drives. Over that time I became convinced that students learn the subject best when three ingredients are combined: a clear physical picture of how each converter behaves, a firm grounding in the mathematics that predicts that behaviour, and a steady diet of worked examples that connect the two. I have tried to keep all three in balance on every page.
The organisation of the book follows the natural flow of the subject. We begin with the switching devices themselves-diodes, thyristors, and the modern controllable switches such as the MOSFET and IGBT-because a converter can be no better than the switches from which it is built. From there we move systematically through the four fundamental conversion tasks: alternating current to direct current (rectification), direct current to direct current (choppers and switched-mode supplies), direct current to alternating current (inversion), and alternating current to alternating current (controllers and cycloconverters). Later chapters treat resonant conversion, gate drives and protection, electric drives, renewable-energy interfaces, dynamic modelling and control, and the wide-bandgap devices that are reshaping the field.
Throughout, I have adopted the convention of analysing every converter first under idealised assumptions, so that the essential input-output relationship stands out clearly, and only then adding the practical non-idealities-device drops, conduction and switching losses, source inductance, ripple, and the like-that a practising engineer must respect. Each chapter closes with a set of graded review problems and, in most cases, a mini-project that invites the reader to design or simulate a small system of their own.
No book of this kind is written in isolation. I am grateful to the generations of students whose questions sharpened my explanations, to my colleagues for many illuminating discussions, and to my family for their patience during the long evenings of writing. I hope that this volume conveys some of the fascination that has kept me engaged with power electronics for my entire professional life, and that it serves the reader well-whether as a course text, a self-study companion, or a reference to return to.