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The third difference between salient pole and cylindrical pole is that the cylindrical pole (non-salient) design is much more durable and has a much lower winding loss than a salient pole unit. Next, its diameter is smaller but the axial length is longer. Also, both winding and noise are less than salient polar rotors.
What is salient and non-salient pole?
Non-Salient pole generators will have smaller diameter and longer axial length. They are used for High speed operation (typically speed will be 1500 and 3000 rpm) Better in dynamic balancing because of absence of salient poles.
What is the difference between salient pole and non-salient pole rotor?
Salient pole rotors have large diameter and shorter axial length. Flux distribution is relatively poor than non-salient pole rotor, hence the generated emf waveform is not as good as cylindrical rotor. Salient pole rotors generally need damper windings to prevent rotor oscillations during operation.
What is the meaning of salient pole?
: a magnet pole that projects toward the armature of an electric machine — compare consequent pole.
What are the advantages of salient pole type construction?
Advantages of salient-pole type construction are : They allow better ventilation. The pole faces are so shaped that the radial air gap length increases from the pole center to the pole tips so that the flux distribution in the air-gap is sinusoidal in shape which will help the machine to generate sinusoidal emf.
What does non salient mean?
Adjective. nonsalient (not comparable) Not salient.
Why synchronous motors are not self starting?
Above a certain size, synchronous motors are not self-starting motors. This property is due to the inertia of the rotor; it cannot instantly follow the rotation of the magnetic field of the stator. Once the rotor nears the synchronous speed, the field winding is excited, and the motor pulls into synchronization.
Which kind of rotor is most suitable for turbo alternators which are designed to run at high speed?
Smooth cylindrical type rotor is generally used for high speed alternators or turbo alternators.
Which alternator is the salient pole type rotor used?
The salient pole type motor is generally used for low-speed operations of around 100 to 400 rpm, and they are used in power stations with hydraulic turbines or diesel engines.
What do you mean by synchronous speed?
: a definite speed for an alternating-current machine that is dependent on the frequency of the supply circuit because the rotating member passes one pair of poles for each alternation of the alternating current.
What is meant by synchronous machine?
: a dynamoelectric machine (such as a generator or motor) that has a constant magnetic field and an armature which receives or delivers alternating current in synchronism with the motion of the machine and at a frequency equal to the product of the number of pairs of poles and the speed of the machine in revolutions.
What is XD and XQ?
Xd- Direct-axis Synchronous Reactance the ratio of fundamental A.C. armature Voltage to A.C. armature current produced by the direct-axis flux. Xq- Quadrature-axis Synchronous Reactance the ratio of fundamental A.C. armature Voltage to A.C. armature current produced by the quadrature-axis flux.
What is a salient pole synchronous motor?
Synchronous Motors Laminated Salient Pole Rotors. Power Conversion’s Laminated Salient Poles Motors have laminated poles fitted with strip or wire wound field coils and supplied with a shock absorbing winding on the outer pole face.
What is the speed of synchronous motor?
The synchronous speed is the speed of the revolution of the magnetic field in the stator winding of the motor. It is the speed at which the electromotive force is produced by the alternating machine.Synchronous Speed. Number of Poles Synchronous Speed NS in r.p.m 10 600 12 500.
What are the prime movers used for a salient pole alternator and non salient pole alternator?
The prime movers used for salient pole alternators are water wheels like Kaplan turbine, Francis turbine, Pelton wheel etc., and diesel or petrol engines. The prime movers used for non-salient pole alternators are steam turbines and gas turbines.
Is the speed of an alternator increases the frequency?
AS THE SPEED OF AN ALTERNATOR INCREASES, THE FREQUENCY.
Can a person be salient?
Salience Definition The term salient refers to anything (person, behavior, trait, etc.) that is prominent, conspicuous, or otherwise noticeable compared with its surroundings. Salience is usually produced by novelty or unexpectedness, but can also be brought about by shifting one’s attention to that feature.
What is a salient example?
The definition of salient is something that is very noticeable, jumps or is prominent. An example of salient is a large dark mole on someone’s forehead. An example of salient is a key point in a proposal. The bell tower is the most salient feature on campus.
What is the meaning of salient features?
What Are “Salient Features”? Dr. Roman-Lantzy defines salient features as, “the defining elements that distinguish one target from another.” (Roman-Lantzy, p. “They are,” she continues, “the key pieces of distinct information that facilitate recognition of an image, object, environment, or person” (Roman-Lantzy, 2018).
Which motors are not self starting?
Above a certain size, synchronous motors are not self-starting motors. This property is due to the inertia of the rotor; it cannot instantly follow the rotation of the magnetic field of the stator.
Why the speed of synchronous motor is constant?
Synchronous motors are constant speed motors. They run at the synchronous speed of the supply. As you can see, the synchronous speed depends on the frequency of the supply and the number of poles of the rotor. Changing the number of poles is not easy, so we do not use that method.
Which method is used for magnetic locking?
2. Which method is/are used to perform magnetic locking? Explanation: A sub motor is needed to make the synchronous machine run till the speed of synchronous speed and to achieve that we need additional motor.
Why are turbo-alternators run at very high speeds?
High speed alternators are called as Turbo alternators. The range of speed is 1500 to 3000 rpm. To provide high speed of rotation, the rotor diameter is reduced, and the axial length is increased.
How is turbo alternator driven by?
Explanation: The turbo alternators are one category among the synchronous machines. They are driven by the steam turbines. The speed of the turbo-alternators is 1000 MW.
What is the rating of turbo-alternators?
Explanation: The generation voltage normally used are 15 kV for 100-200 MW machines. The voltage range for the large turbo-alternators are 20-25 kV.
What are the advantages of salient pole rotor?
reduced noise. reduced windage loss. adoptability to low and medium speed operation.
What is maximum speed of 50 Hz alternator?
Answer is “3000 rpm”.
Which material is used in armature core of alternator?
This is why armature cores are made up of many thin pieces of iron, rather than a large, solid piece. These individual, thin pieces have a higher resistance than one solid piece, and therefore, produce less eddy currents and experience lower eddy current loss.
