Electric motors and transformers can be found in applications from computer disk drives, appliances, cars, power supplies, laptop and cell phone chargers, to industrial process lines, pumping systems, conveyers, escalators, and many more. For example, modern building services are heavily reliant upon electrical motors and drives, found in air conditioning, ventilation, and heating systems, or elevators. All electric motors have a stationary part (component), the stator, a moving part (component), the rotor, and interface with energy supply and eventually control and protection subsystems. Transformers are electric energy convertors, operating on Faraday's law of induction, designed to step up or step down the voltages as required by the loads. Motors and transformers are introducing a great deal of flexibility in power transmission, distribution, and use. The precision of control, introduced by electric motors, through the application of torque, speed, and position control has been critical and central to all aspects of industrial processes, automation, or transportation. This chapter focuses on the analysis and description of electric transformers and main types of electric motors used in commercial and industrial applications. The reader is advised that the chapter content and materials are critical for the understanding of several book topics. Motor and transformer construction, components, characteristics, and performances are included and discussed in details, together with short discussion of the common transformer and motor applications. A short discussion of energy conversion is also included in this chapter. This chapter also discusses on equivalent circuits, power, torque, and losses of transformers, induction and synchronous motors, as well as the most common type of DC motors. Several examples are also included in all chapter sections to facilitate the chapter topics understanding.

Chapter Contents:

• Objectives and abstract
• 3.1 Introduction
• 3.1.1 Transformers in electrical systems
• 3.1.2 Electromechanical energy conversion systems
• 3.2 Transformer theory, construction, and design
• 3.2.1 Polarity of transformer windings
• 3.2.2 Practical (non-ideal) transformers
• 3.2.3 Voltage regulation
• 3.2.4 Multi-winding transformer
• 3.2.5 Transformer ratings, categories, types, and tap changers
• 3.2.6 Transformer connections
• 3.2.7 Transformer efficiency
• 3.3 AC electrical motors
• 3.3.1 Electric motor fundamentals
• 3.3.2 Synchronous motors
• 3.3.3 Induction motors
• 3.4 DC machines
• 3.5 Chapter summary
• Further readings
• Questions and problems

Inspec keywords: transformers; synchronous motors; DC motors; equivalent circuits

Other keywords: power; electric energy convertors; torque; DC motors; synchronous motors; equivalent circuits; electrical motors; energy conversion; electric transformers; induction motors

Subjects: Transformers and reactors; Synchronous machines; d.c. machines