Electric Machines

1

Introduction

Seungdeog ChoiPh.D.

Toshiba International

The population of electric motors has greatly increased in recent years, not only in the United States but also in the world market as shown in Table 1.1 and Table 1.2. The world market is expected to be around $16.1 billion in 2011, which is assumed more than 50% growth just within 5 years [1]. Electric motors have been applied to almost every place in our daily life, such as manufacturing systems, air transportations, ground transportations, building air-conditioner systems, home energy conversion systems, various cooling systems in electrical devices, and even cell phone vibration systems.

It is also a well-known fact that the electric motors consume more than 50% of whole electrical ...