A synchronous generator is a type of electric machine that converts mechanical power into electrical power. It does this by rotating a magnetic field inside a stator winding, which induces an electric current in the winding. The current is then used to power electrical loads.
The excitation of a synchronous generator is the process of creating the magnetic field that rotates inside the stator winding. This is done by applying a DC voltage to the field winding.
If the excitation of a synchronous generator fails, the magnetic field will collapse. This will cause the generator to stop generating electricity and it will start to act like an induction motor.
An induction motor is a type of electric motor that converts electrical power into mechanical power. It does this by rotating a magnetic field inside a rotor winding, which induces an electric current in the winding. The current is then used to create a magnetic field that opposes the stator’s magnetic field. This opposition creates a torque that causes the rotor to spin.
When a synchronous generator loses excitation, it will start to act like an induction motor because the stator’s magnetic field will still be present. The rotor will then start to spin and generate electricity, but it will be consuming power from the electrical grid instead of producing power.
Here are some of the effects of a synchronous generator losing excitation:
The generator will stop generating electricity.
The generator will start to act like an induction motor.
The generator will consume power from the electrical grid.
The generator may overheat or be damaged.
It is important to protect synchronous generators from losing excitation. This can be done by using a device called an exciter. The exciter provides the DC voltage that is used to create the magnetic field in the generator. If the exciter fails, the generator will lose excitation.