Synchronouse Generator

The synchronouse Generator :

 

electric generator:

It is a mechanical device that converts kinetic energy into electrical energy in the presence of a magnetic field and works with electromagnetic induction, which is the basis for generating inductive current.

Generator Components:

  The generator consists of two parts (mechanical part - electrical part).

The mechanical part: 

consists of the fixed member (Stator) and the moving member (Rotor).

One of them carries the coils for the production of electric power and is called the Armature, and the other carries the coils of the magnetic field. It is preferable that the coils for the production of electric energy are installed on the stator (Stator) and the coils of the production of the magnetic field are installed on the rotor.

For reasons including:

The drawn current is very large, so it is preferable to take it directly and not through slip rings.

Eliminate slip rings or reduce them to be 2 instead of 6.

Ease of cooling the electric power output coils when they are fixed.

The rotor that carries the coils of the magnetic field is fed a constant current through the two slip rings, and we know that the current passing through The rotor has a constant current, so it is made of solid iron and not in the form of strips to prevent the eddy currents.

The electrical part:

 consists of the carrier frame, which is the output of energy. The coils of this frame generate electrical power.

  Field coils: It is the product of the magnetic field, a small amount of the field coils current is transmitted to the moving part to start the process of rotation.

How the synchronous generator works:

When moving the rotor part through the rotating shaft and the output of the movement is through a gas, steam or water turbine

Or other things, when its speed reaches the synchronous speed, the coils of the rotor are fed with direct current through a special generator on the same shaft through two sliding rings that were with an external generator. The fixed member generates an electromotive force distributed on 3 phases, i.e. 3 phase, and the angle between each phase and the other is 120 degrees to produce a regular electric current (Sinusoidal wave).

Synchronous machine tests:

Open Circuit:

  In this test, the ends of the product are left open and the machine is rotated until it reaches the synchronous speed, and when the current of the field increases gradually, and this increase in current works to increase the magnetic flux and thus increase the voltage generated on its ends. The values ​​of voltage and current are recorded in a table called the no-load test.

Short Circuit:

The three terminals of the product are shorted together and the machine is also rotated until it reaches the synchronous speed, then the field current is gradually increased, and the value of the voltage and current is recorded.

Voltage Regulating Coefficient:

The Voltage Requlation is very important, as it gives an idea of the extent to which the voltage changes on its ends when the machine is loaded or when the loads change significantly and is expressed by the relationship

VR = Eph - Vph / Vph *100