ABSTRACT
The population of electric motors has greatly increased, not only in the United States but also in the world market. 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 energy demand in the United States. With the rapidly increased population and huge electric energy consumption, sophisticated control and reliability of motor operations from a harsh industrial environment has been a major requirement in many industrial applications. The electric motor design is commonly intended to have electrical and mechanical symmetry in the stator and the rotor for better coupling and higher efficiency. The fault diagnosis of electrical motors is expected to provide warning of imminent failures, diagnosing scheduling information for future preventive maintenance.
