The field of electrical engineering has three main divisions—electronics, power, and control. Power Electronics is a discipline that combines these three divisions. Power Electronics is the application of solid state electronic switching circuits to control the flow of electrical energy. This is the technology that drives power converters, inverters, switching power supplies, and motor drives and soft starters. Since the last three decades, the field of power electronics has been evolving rapidly. Starting with conventional thyristor devices, the book traces all the advancements in the field. The book starts with an overview of power electronics systems, the principles and characteristics of thyristors, gate triggering circuits, and series and parallel operations of thyristors. Then, the book progresses to modern power semiconductor devices, phase controlled converters, dual converters, choppers, and inverters. It also covers cyclo-inverters, A.C. Regulators, resonant converters, protection, cooling and mounting of thyristors, control of A.C and D.C drivers, and thyristor applications. The book also includes nearly 397 Multiple Choice Questions (MCQs), 501 review questions, 194 solved problems, and 104 unsolved problems. The book’s companion website provides computer simulation examples of power electronics circuits.