What is salient pole synchronous generator?
Salient-pole synchronous generators (SGs) are widely used for various purposes such as hydro generators and engine generators. One of their problems is magnetic saturation in the rotor field poles. The magnetic saturation limits the armature terminal voltage and requires a large field mmf.
Which is true about salient pole rotor in synchronous generator?
Salient Pole Rotor A salient pole synchronous machine has a non-uniform air gap. The air gap is minimized under the pole centers and it is maximum in between the poles. They are constructed for medium and low speeds as they have a large number of poles. A salient pole generator has a large diameter.
What is the difference between cylindrical rotor synchronous generator and salient pole synchronous generator?
non-salient pole rotors are used in nuclear, gas, and thermal power plants. The last difference between salient pole and cylindrical pole is that the rotor of the cylindrical pole can run at a higher rotational speed, provided that the rotor is easily balanceable and the centrifugal force can be equally distributed.
What do you mean by the salient pole type rotor?
Salient pole type of rotor consist of large number of projected poles (salient poles) mounted on a magnetic wheel. They are larger in diameter and smaller in axial length. Non-salient pole rotors are cylindrical in shape having parallel slots on it to place rotor windings.
Where are salient pole generators used?
Hence salient pole generators are used in hydropower plants. Non-salient pole-type rotors are used in high-speed alternators having speeds between 1500 rpm to 3000 rpm. Salient pole rotors are used in low-speed devices, from 100 rpm to 1500 rpm.
What is non-salient pole rotor?
Non-salient pole rotors are cylindrical in shape having parallel slots on it to place rotor windings. It is made up of solid steel. The construction of non-salient pole rotor (cylindrical rotor) is as shown in figure above. Sometimes, they are also called as drum rotor.
How does a salient pole rotor work?
A salient pole rotor is made from steel laminations to minimize loss of electric current. This is because the rotor is subject to magnetic field changes. Poles with the same dimensions are assembled to the necessary length via stacking laminations. There is a non-uniform air gap in a salient pole rotor.
What are the characteristics of salient pole synchronous machine?
Which of the following is a characteristic of a salient pole synchronous machine?
- Uniform air gap.
- Flux produced by armature wave is independent of spatial orientation of the wave with respect to field poles.
- Constant reluctance.
- Reluctance along the direct axis is smaller than that along the quadrature axis.
What are the advantages of cylindrical type of rotor?
Cylindrical rotors are used in high speed electrical machines, usually 1500 RPM to 3000 RPM. Windage loss as well as noise is less as compared to salient pole rotors. Their construction is robust as compared to salient pole rotors.
Which winding is used for salient type rotor?
Salient pole rotors generally need damper windings to prevent rotor oscillations during operation. Salient pole synchronous generators are mostly used in hydro power plants.
Why salient pole rotor is used for low and medium speed and non-salient pole rotor is used for high speed synchronous generators?
Salient pole rotors have large diameter and shorter axial length. They are generally used in lower speed electrical machines, say 100 RPM to 1500 RPM. Flux distribution is relatively poor than non-salient pole rotor, hence the generated emf waveform is not as good as cylindrical rotor.
What is the difference between salient and non-salient pole synchronous generators?
Salient pole synchronous generators are mostly used in hydro power plants. Non-salient pole rotors are cylindrical in shape having parallel slots on it to place rotor windings. It is made up of solid steel. The construction of non-salient pole rotor ( cylindrical rotor) is as shown in figure above.
What is salient pole rotor?
On the extreme outermost periphery, copper bars are inserted and the rings forming damper winding is cut on both sides. A salient pole rotor is usually found in large (many MW), low-speed, including hydrogen generators or higher-speed machines, up to 1-2 MW.
What are the types of synchronous generators?
There are mainly two types of Synchronous Generator from rotor construction point of view. The two main types of synchronous machine are Cylindrical Rotor and Salient Pole. Saliency simply means projection outward. Therefore from the literal meaning of Saliency one can guess that Salient Pole machines must have poles projecting outward.
What is salient pole theory of synchronous machines?
In this tutorial, we discuss What is SALIENT POLE THEORY of SYNCHRONOUS MACHINES. Synchronous machines are types of machines that operate at synchronous speed.
