From Electric Machinery and Transformers, Third Edition

3.1 Introduction

We all know that energy exists in many forms, and we use numerous devices on a daily basis that convert one form of energy into another. When we speak of electromechanical energy conversion, however, we mean either the conversion of electric energy into mechanical energy or vice versa. For example, an electric motor converts electric energy into mechanical energy. On the other hand, an electric generator transforms mechanical energy to electric energy. In this chapter, our aim is to explore the basic principles of electromechanical energy conversion.

Electromechanical energy conversion is a reversible process except for the losses in the system. The term "reversible" implies that the energy can be transferred back and forth between the electrical and the mechanical systems. However, each time we go through an energy conversion process, some of the energy is converted into heat and is lost from the system forever.

When a current-carrying conductor is placed in a magnetic field, it experiences a force that tends to move it. If the conductor is free to move in the direction of the magnetic force, the magnetic field aids in the conversion of electric energy into mechanical energy. This is essentially the principle of operation of all electric motors. On the other hand, if an externally applied force makes the conductor move in a direction opposite to the magnetic force, the mechanical energy is converted into electric energy. Generator action is based upon this principle. In both cases, the magnetic field acts as a...

Copyright Oxford University Press, Inc. 2001 under license agreement with Books24x7

Products & Services
Electrical Winding Services
Companies that specialize in the fabrication of custom wound assemblies for a wide range of electrical applications and industries. Electrical winding services also includes the repair and refurbishing of individual wound components.
Electric Brakes
Electric brakes are assemblies consisting of electrical elements for the slowing or stopping of shafts in equipment drives. Electrical power is required to activate the brake.
Magnetometers
Magnetometers are scientific instruments that measure the strength and/or direction of a magnetic field. There are two basic types: scalar and vector.
AC Motors
AC motors include single, multiphase, universal, induction, synchronous, and gear motors. They also include servomotors.  

Topics of Interest

4.1 Introduction If we arrange two electrically isolated coils in such a way that the time-varying flux due to one of them causes an electromotive force (emf) to be induced in the other, they are...

1.1 Introduction Without any reservation or exaggeration, we can say that the availability of energy in the electric form has made our lives much more comfortable than ever before in the history of...

AC MACHINE FUNDAMENTALS (CHAP. 5) 1. What is the difference between a motor and a generator? 2. Why is the conversion of energy in motors and generators occurring between mechanical energy and...

ELECTRIC MACHINES AND TRANSFORMERS An electric machine is a device that can convert either mechanical energy to electric energy or electric energy to mechanical energy. Such a device is called a...

ELECTRIC MACHINES AND TRANSFORMERS An electric machine is a device that can convert either mechanical energy to electric energy or electric energy to mechanical energy.1 Such a device is called a...