Universities throughout the world typically provide an excellent education in the various aspects of electronics, however their focus is normally on traditional low power electronics. In contrast, in the industrial environment, there is a need for high power electronics that is used to control electromechanical systems in addition to the low power electronics typically employed for analog and digital systems. To address this need, Section 1 of this volume in The Industrial Electronics Handbook, Second Edition, is focused on special high power semiconductor devices. Section 2 not only describes the various types of electrical motors and their principles of operation, but their limitations as well. Since electrical power can be delivered in either ac or dc, there is a need for high efficiency devices that perform the necessary conversion between these different types of power. These aspects are covered in the Section 3. Section 4 on Motor Drives is dedicated to a presentation of very specialized electronic circuits for the efficient control of electric motors. There are also many other applications for power electronics, such as lighting, renewable energy conversion, and automotive electronics, and these topics are covered in Section 5 under the heading of Power Electronics Applications. The last section of this volume covers the power electronics that are employed in very high power electrical systems for the transmission of energy. The four other volumes in the Handbook are available individually: Fundamentals of Industrial Electronics, Industrial Communication Systems, Intelligent Systems, and Control and Mechatronics. Additionally, all of the volumes are available as a set.