Motors, alternating current induction

Single-phase Motors. Alternating-current single-phase motors are usually induction or series motors, although single-phase synchronous motors are available in the smaller ratings. 

Tesla, Nikola (1856-1943) Born in modern-day Croatia, the brilliant if eccentric Tesla came to the United States in 1884 to work for Thomas Edison s company and later for Edison s rival George West-inghouse (1846-1914). In 1891, Tesla became a naturalized American citizen. A physicist, mechanical and electrical engineer, and an inventor specializing in electromagnetism, he created fluorescent lighting, pioneered wireless communication, built an alternating- current induction motor, and developed the Tesla coil, variations of which have provided the basis for many modern electrical and electronic devices. 

Alternating-Current Squirrel-Cage Induction Motors. 29-4... 

Alternating-Current Motors, Wound-Rotor Induction. 29-7... 

Alternating-Current Squirrel-Cage Induction Motors These motors are by far the most common constant-speed drives. They are relatively simple in design and therefore both low in cost and highly reliable. Representative prices are shown in Fig. 29-1 for various speeds and horsepowers. 

Alternating-current motors are classified as induction motors or synchronous motors. Faraday found that a stationaiy wire in a magnetic field produced no current. However, when the wire continues to move across magnetic lines of force, it produces a continual current. When the motion stops, so does the current. Thus Faraday proved that electric current is only produced from relative motion between the wire and magnetic field. It is called an induced current—an electromagnetic induction effect. 

Figure 14-2A. Alternating current (AC) induction motor cross-sectional view of 220/440V, 3-phase, 60-cycle, totally enclosed fan-cooled standard motor. (Used by permission Reliance Electric Co., Div. Rockwell Automation.)...

A general-purpose alternating-current motor is an induction motor, rated 200 horsepower and less, which incorporates all of the following ... 

Alternating-current motors are of three general types, induction, synchronous, and series, and are defined as follows ... 

Induction Motors. An induction motor is an alternating-current motor in which a primary winding on one member (usually the stator) is connected to the power source and a polyphase secondary winding or a squirrel-cage secondary winding on the other member (usually the rotor) carries induced current. There are two types ... 

Use of wound-rotor induction motors has been largely in continuous-duty constant-speed supplications where particularly high starting torques and low starting currents are required simultaneously, such as in reciprocating pumps and compressors. These motors are also used where only alternating current is available to drive machines that require speed adjustment, such as types of fans and conveyors. 

Rectification — is defined as the conversion of -> alternating current, AC, into pulsating -> direct current, DC, by any means other than the use of a motor-generator. That is, the AC is primarily converted by use of a -> rectifier into (unfiltered) unidirectional half-cycles. The percentage ratio of the DC output voltage to the peak AC input voltage of a certain rectifier device is called rectification efficiency. A circuit containing parallel -> capacitance, sometimes in combination with series inductance, is afterwards frequently applied as rectification filter in order to smooth the ripple in the DC current output. A combined device of rectifier and filter is called rectifier-filter system. 

Alternating current for induction motors and furnaces (three phase and single phase) and... 

Induction motor (Nikola Tesla) Tesla s theories and inventions make alternating current (AC) practical. 

NEMA Standards Publication MG13-1984 (Reaffirmed 1990), Frame Assignments for Alternating-Current Medium Induction Motors, National Electrical Manufacturers Association, Washington, D.C.. 1984. 

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