Contents
- 1 How do synchronous generators work?
- 2 What causes loss of excitation in generator?
- 3 What is the basic principle of synchronous generator?
- 4 What are the advantages of a synchronous generator?
- 5 How does pitch control affect a synchronous generator?
- 6 How is phase voltage induced in a synchronous generator?
How do synchronous generators work?
The synchronous generator works on the principle of Faraday laws of electromagnetic induction. Electromagnetic induction states that electromotive force induced in the armature coil if it is rotating in the uniform magnetic field. The EMF will also be generated if the field rotates and the conductor becomes stationary.
What causes loss of excitation in generator?
Generator loss of excitation (LoE) can be caused by a short circuit in the field winding, unexpected field breaker opening and by a failure in the excitation system. According to Chinese statistics, generator failure due to LoE accounts for more than 60% of all generator failures [1].
What is the purpose of an exciter in a generator?
A Exciter. The exciter supplies direct current to the field winding of the generator, at whatever voltage is required to overcome the resistance of the winding.
What is the basic principle of synchronous generator?
The principle of operation of synchronous generator is electromagnetic induction. If there exits a relative motion between the flux and conductors, then an emf is induced in the conductors.
What are the advantages of a synchronous generator?
One advantage of a synchronous generator is that it can produce utility-type power without an external power grid. The unit must provide its own voltage and frequency control and not depend on the utility. Additionally, most synchronous generators are used with machines that have rotor blades with variable pitch control.
Can a synchronous generator be connected to the grid?
A synchronous generator may not be directly connected to the grid as discussed above, unless a variable ratio gearing system is implemented. Therefore, most commercially available synchronous generators in wind power applications use a full-scale power electronic converter.
How does pitch control affect a synchronous generator?
The pitch control mechanism increases the cost of the turbine and causes stress on turbine and generator [ 168 ]. Synchronous generators in variable speed operation will generate variable voltage and variable frequency power. Using an AVR for the excitation of the field voltage, the output voltage of the synchronous generator can be controlled.
How is phase voltage induced in a synchronous generator?
When the rotor of a synchronous generator is spinning, a voltage EA is induced in its stator. When a load is connected, a current starts flowing creating a magnetic field in machine’s stator. This stator magnetic field BS adds to the rotor (main) magnetic field BR affecting the total magnetic field and, therefore, the phase voltage.