Definition and Main Components of Synchronous motors

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Synchronous motor is an AC motor, working on speed fixed frequency of the system. These motors require Direct Current (DC) for excitation and have a low starting torque, and therefore synchronous motor suitable for use beginning with low load, such as air compressors, frequency changes and the motor generator.

Synchronous motor is able to correct the power factor of the system, so often used in systems that use a lot of electricity.

The main components of a synchronous motor are:

Rotor. The main difference between synchronous motors with induction motor is that the rotor synchronous machine running at the same speed as the rotating magnetic field. This is possible because the magnetic field of the rotor is no longer induced.

The rotor having permanent magnets or DC-excited, which forced to lock in a certain position when confronted with another magnetic field.

Stator. Stator produces a rotating magnetic field, which is proportional to the frequency supplied.

AC Generator Excitation

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Excitation system conventionally from an alternating current generator consisting of a direct current source connected to the AC generator field via slip-rings and brushes. DC source is usually obtained from a direct current generator driven by the motor or drive the same first mover generator back and forth at first. After the arrival of solids, some of the different excitation systems have been developed and used.

In similar systems, it is used by the generator with a capacity greater power is the power rectifier incorporated into solids separate from the three-phase winding that is located above the generator stator grooves. The only function of this coil is to provide excitation power for the generator.

Output that have rectified from the exciting AC, given directly to the relationship that was isolated along the shaft to a rotating field synchronous generators. The field of the exciting ac is stationary and powered from a separate DC source. Means, that the voltage generated by the synchronous generator can be controlled by changing the exciting AC field strength.

Mechanical Principle of AC Generators

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AC generator works based on the electromagnetic induction basic principle. Alternating voltage to be generated by the rotation of magnetic field in a stationary coil anchor. In this case the field coil is located on the same piece with the rotor of the generator. The value of the voltage generated depends on:

  1. The number of windings in the coil.
  2. Strong magnetic field, if the field is strong, then the voltage that induced will be larger.
  3. Rotational speed of the generator.

The principle of this generator can be simply explained that the voltage will be induced on the conductor when the conductor is moving in a magnetic field so that the cutting lines of force. Applicable law right hand on the generator which states that there is a relationship between the conductor moves, the magnetic field direction, and the resultant direction of current flow is induced.

When the thumb indicates the direction of motion of the transmitter, the thumb indicates the direction of flux; the middle finger shows the direction of inducted electron flow. This law also applies when the magnet instead of the sender is moved.

There are two types of construction of an AC generator; Stationary Fields and Rotating Magnetic Field.