1. How does the electricity from the generator come from

Faraday's law of electromagnetic induction: When a part of a conductor in a closed circuit cuts through a magnetic induction line, an induced current is generated.

Right hand rule: Open your right hand so that your four fingers are perpendicular to your thumb, with your thumb pointing in the direction of the conductor's movement, and let the magnetic induction line pass through the palm of your hand. The direction of your four fingers is the direction of the current.

2. Generator structure

The generator is composed of components such as rotor, stator, brush, fan, end cover, bearing seat, and bearings. The fan plays a cooling role, and generally the generator is placed on a hollow platform in the lower part and cooled by air; The end cover and bearing seat connect the rotor and stator together; Bearings are usually connected to other machinery that provides power, such as steam turbines. The rotor is driven by bearings to cut the magnetic field in the stator, thereby generating induced electromotive force.

3. Generator principle

The normal speed of the generator in our country is 3000r/min, and it cuts the magnetic induction line 50 times per second, which is 50Hz. The iron core (rotor) of the generator is wound with three sets of excitation coils. Each rotation of the three sets of excitation coils cuts the magnetic induction line once, inducing three phases of the same frequency. Their heads are connected to three-phase A, B, and C respectively, also known as live wires, and their ends are connected together to form a common point, which is the center point O (zero wire).

The rotor of a large generator is equipped with an excitation coil, which is fed with direct current to become a magnet. It is driven by a prime mover such as a steam turbine or water turbine to rotate, generating a rotating magnetic field that cuts the stator coil of the generator and induces alternating current. What we learn in books is that when a magnet is stationary, the coil rotates and cuts through the magnetic field lines to generate induced current, while in a power plant, the generator is exactly the opposite, with the coil stationary and the magnet rotating. No matter who moves or remains still, they move and move together.