19-06-2010, 11:56 AM
Introduction :
Several different technologies are used in the generator portion of wind turbines (wind generators). One of the older, more reliable technologies is the brushless DC alternator. Basic Theory of Brushless Alternator is nothing but When an electric current is passed through a coil of wire, a magnetic field is produced (an electromagnet). Conversely, when a magnetic field is moved through a coil of wire, a voltage is induced in the wire. The induced voltage becomes a current when the electrons have some place to go such as into a battery or other load.Both of these actions take place in alternators, motors and generators or dynamos. Voltage is generated when a coil of wire is moved through a magnetic field. It doesnâ„¢t matter whether the coil is moving or the magnetic field is moving. Either configuration works equally well and both are used separately or in combination depending on mechanical, electrical and other objectives. The old DC generators (dynamos) used a stationary field and rotating armature. Automotive alternators use the opposite configuration with a rotating field and stationary armature. In this seminar we describe the latest advancement in the field of Brushless Alternator
normally Brushless Alternators are of inductor type. They are used in railway coaches for supplying loads like lights, fans and for charging automobile batteries. These alternators are 3f homo polar generators without any commutators, slip-rings and sliding contacts (brushes). Brushless alternators are of two types:-
1. Brushless alternator with stationary armature winding and stationary field winding.
2. Brushless alternator with stationary armature winding and rotating field winding
