A synchronous generator is a device that converts mechanical energy into electrical energy through the use of electromagnetic induction. It is commonly used in power plants to produce electricity.
The Open Circuit Characteristic (OCC) is a graph that shows the relationship between the generator's terminal voltage and field current when there is no load connected to the generator. It is used to determine the generator's field current and excitation requirements.
Residual magnetism refers to the small amount of magnetic field that remains in the generator's rotor when it is not connected to a power supply. This residual magnetism is necessary for the generator to produce electricity and is typically created by passing a small direct current through the generator's field winding.
Residual magnetism is important because it helps in the self-excitation process of the generator. This means that the generator can start producing electricity without the need for an external power source to provide the initial magnetic field. Without residual magnetism, the generator would not be able to start producing electricity on its own.
Residual magnetism can be maintained by regularly running the generator and keeping it connected to a power source. This ensures that the magnetic field in the rotor is constantly replenished. Additionally, if the generator is not used for a long period of time, it is important to pass a small direct current through the field winding to maintain the residual magnetism.