The working principle of the generator

The working principle of a generator

Structure and Principle

1. Structure

The synchronous generator is primarily composed of the stator, rotor, and other components.

The stator section includes the stator core, stator winding, and base; the rotor section includes the rotor core, excitation winding, and slip rings (for hidden pole rotors, there are also sleeve and core; for salient pole rotors, there are poles, yokes, and rotor brackets); other components include brush devices, end covers, bearings, and fans, etc.

2. Working Principle

The synchronous generator operates based on the principle of electromagnetic induction, converting mechanical energy into electrical energy through the relative motion between the rotor's magnetic field and the stator winding.

When the rotor is driven by an external force, the relative motion between the rotor's magnetic field and the stator's conductors occurs, meaning the conductors cut through the magnetic lines of force. Consequently, an induced electromotive force (EMF) is generated in the conductors, whose direction can be determined by the right-hand rule.

Due to the position of the rotor poles, the conductor cuts the magnetic lines of force vertically, resulting in a significant induced electromotive force in the stator winding at this point.

After the magnetic poles rotate 90 degrees, they become horizontal, and the conductor does not cut the magnetic field lines, resulting in zero induced electromotive force (EMF). When the rotor turns another 90 degrees, the fixed stator winding cuts the magnetic field lines vertically again, causing the induced EMF to reach a higher value, but in the opposite direction.

As the rotor rotates an additional 90 degrees, the induced electromotive force (EMF) becomes zero again. This means that as the rotor completes one revolution, the induced EMF in the stator windings alternates between positive and negative. If the rotor continues to rotate at a constant speed, a periodic alternating EMF is induced in the stator windings.