The excitation system of a synchronous generator is essential for the following reasons:
1. Generation of Magnetic Field
- The excitation system provides direct current (DC) to the rotor winding of the synchronous generator, creating the magnetic field necessary for inducing voltage in the stator windings.
2. Voltage Regulation
- By controlling the field current, the excitation system maintains a stable output voltage of the generator under varying load conditions.
3. Reactive Power Control
- The excitation system adjusts the generator's reactive power output to maintain power factor and voltage stability in the electrical network.
4. Stability and Damping of Oscillations
- Modern excitation systems include automatic voltage regulators (AVRs) that help improve the stability of the power system by damping oscillations and responding to transient disturbances.
5. Control of Synchronization
- The excitation system ensures that the generator stays synchronized with the grid by maintaining the correct rotor magnetic field strength.
6. Protection Against Overload
- Advanced excitation systems can protect the generator by limiting the field current during abnormal conditions, such as faults or overloading.
In summary, the excitation system is critical for controlling and stabilizing the performance of a synchronous generator, ensuring efficient and reliable operation.
