- Electrical machine
Electrical machine is a device that convert either
mechanical energyto electrical energyor vice versa, and change AC voltagefrom one level to another level.
Electrical machines are divided into three parts:
Generatoris the device that converts mechanical energyat its to produce constant electrical energyat its output. Generatoris classified into two types: AC generatorand DC generator.
AC generatoris the generator that converts mechanical energyat its into AC electricity. AC generatoris classified into several types:
Asynchronous AC generatoror induction AC generator, an AC generator whose field current is supplied by magnetic induction into the field windings.
Synchronous AC generator, an AC generator whose magnetic field current is provided by a separate DC current source, either external DC sourceor mounted DC source.
DC generatoris the generator that converts mechanical energyat its into DC electricity. DC generatoris classified into several types:
Cumulatively compounded DC generator, a DC generator whose both shunt fieldand series fieldare present and their effects are additive.
Differentially compounded DC generator, a DC generator whose effects of shunt fieldand series fieldare subtractive.
Separately excited DC generator, a DC generator whose field fluxis produced by a separate power source independent of the generator.
Series DC generator, a DC generator whose field circuitis in series with the armature.
Shunt DC generator, a DC generator whose field circuitis connected directly across the terminals of the generator.
Motoris the device that converts electrical energyat its input to produce mechanical energy. Motoris classified into two types: AC motorand DC motor.
AC motoris the motor that converts AC electrical energyat its input into mechanical energy. AC motoris classified into several types:
Asynchronous AC motoror induction AC motor
Synchronous AC motor
DC motoris the motor that converts DC electricityinto mechanical energy. Its main components are stator, rotor, windings( field windingsand armature windings) and commutator. DC motoris classified into five types:
Compounded DC motor
Permanent magnet DC motor
Separately excited DC motor, a DC motor whose fieldcircuit receives power from a separate constant voltage supply.
Series DC motor, a DC motor whose fieldwindings consist of relatively few turns and connected in series with the armaturecircuit.
Shunt DC motor, a DC motor whose fieldcircuit receives power directly across the armatureterminals.
Losses in DC motor are
brush drop losses, core losses, mechanical lossesand stray losses.
Transformeris the device that converts AC voltagefrom one level to another level higher or lower, or even to the same level with out changing the voltage.
Chapman, Stephen J. 2005. Electrical Machinery Fundamentals. 4th Ed. New York: McGraw Hill.
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