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Why is the speed of synchronous motor is more then induction motor?
Wiki User
∙ 12y ago
Synchronous motors run at synchronous speed. An induction motor that has the same number of poles must run at a sub-synchronous speed to create a second magnetic field (a field that is at a different phase angle) to generate torque.
Wiki User
∙ 12y ago
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What is synchronous machein?
mainly alternator,synchronous motor comes under the synchronous machine.a synchronous motor is not a self starting motor.if a synchronous motor moves with more than synchronous speed then it acts as a synchronous generator.
How many Slip rings in synchronous motor?
If the synchronous motor is single phase then there are two slip rings & if this motor is three phase so the slip rings are three in number. Correction; I have never seen a single phase synchronous motor. It would cost more that it was worth. A synchronous motor has a separately excited field. If the excitation comes from a stationary DC source it has 2 slip (collector) rings. A brushless induction motor has no slip rings because the exciter armature rotates and so do the rectifiers. A permanent magnet motor, used with variable frequency drives, is another type of synchronous motor that has no slip rings. A three phase motor with 3 slip rings is a Wound Rotor motor. Wound rotor motors are variable speed motors that were used for such applications as bridges and cranes before variable speed drives.
What is the importance of slip in a 3-phase induction motor?
Slip is a measure of the difference in relative motion between the rotor and the magnetic field set up by the field windings.In very simple terms, without slip an induction motor would not be able to develop any torque! A slip of zero means that the rotor is turning at synchronous speed; in other words it is running at the same speed as the rotating field set up by the field windings, so there is no relative movement between the field and the rotor. To develop torque, the voltages must be induced into the rotor, and this can only happen if there is relative movement between the field and the rotor -in other words, the rotor MUST be running more slowly than synchronous speed. That is, there must be some degree of slip.
What is the effect of induction motor on power factor?
An induction motor has a lagging power factor. Motors of more than about 2 HP are designed to have a power factor of 0.85 or higher.
What is synchronus capacitor?
A synchronous condenser (also known as a synchronous capacitor or synchronous compensator) is a DC-excited synchronous computer (large rotating generators) whose shaft is now not connected to any using equipment.
Why 3 phase induction motor never atteined sinkronas speed?
Induction motors run at sub synchronous speeds because the slip (difference between synchronous and actual speed) causes, or controls the electric field strength in the motor. As more load is put on the motor, the motor's speed decreases, increasing slip, and increasing the electric field strength.
What is synchronous machein?
mainly alternator,synchronous motor comes under the synchronous machine.a synchronous motor is not a self starting motor.if a synchronous motor moves with more than synchronous speed then it acts as a synchronous generator.
Why synchronous motor is not a self starting motor?
As per the operating principle of the Synchronous motor, due to continuous & rapid rotation of stator poles,the rotor is subjected to a torque which is rapidly reversing i.e. in quick succession,the rotor is subjected to torque which tends to move it first in one direction & then in the opposite direction.Owing to its large inertia,the rotor cannot instataneously respond to such quickly-reversing torque,with the result that it remains stationary or in other words it is not self starting.
What is the importance of speed control of induction motors?
Speed control of any kind of motor is important because it enable the user of the motor to restrain the motor speed to the needed or required speed to accomplish a specific task. omatycoon@gmail.com
Can you run a 230v 60HZ motor on 230v 50HZ power?
You may or you may not. It all depends on the task you are using the motor. If speed is not a concern for you then you may, but for sensitive systems where changes in motor speed affects the system then you may not. The reason is that the frequency of the power supply affects the motor speed. Frequency is directly proportional to speed.
How many Slip rings in synchronous motor?
If the synchronous motor is single phase then there are two slip rings & if this motor is three phase so the slip rings are three in number. Correction; I have never seen a single phase synchronous motor. It would cost more that it was worth. A synchronous motor has a separately excited field. If the excitation comes from a stationary DC source it has 2 slip (collector) rings. A brushless induction motor has no slip rings because the exciter armature rotates and so do the rectifiers. A permanent magnet motor, used with variable frequency drives, is another type of synchronous motor that has no slip rings. A three phase motor with 3 slip rings is a Wound Rotor motor. Wound rotor motors are variable speed motors that were used for such applications as bridges and cranes before variable speed drives.
What happens if you use synchronous motor in ceiling fans?
Synchronous motors are much more efficient at converting electric power into motion. However, the speed of the motor is controlled by the frequency of the electric supply. So a synchronous motor ceiling fan would be much more efficient, but the speed of the fan would not be controllable, unless frequency controlled power supplies (inverter power) are used.
How is single phase induction motor is constructed?
An induction motor is an alternating current (only) motor that has one or more coils of wire wound on a metal frame that induces a current in the conductors in the rotor when the rotor is moving at a different than synchronous speed. Synchronous speed it determined by the line frequency and the number of poles the motor has. For example, a two pole motor with a 60 Hz line frequency would have a synchronous speed of 3600 RPM. When used with single phase, the magnetic field generated in the stator needs to be caused to rotate around the rotor. In most cases this is initiated by a separate starting winding that is fed out of phase with the running winding(s). Once the rotor is rotating, the stator's field rotation has been established and the starting circuit is generally switched off.
Why the no of poles are less in induction machine compared to synchronous machine?
The number of poles determines the speed a machine has to turn (RPMs). The more poles, the slower the machine can turn. I don't believe your statement is true. I've seen synchronous generators, for example, that turn at 1200 RPMS, and induction motors that turn at ~1800RPMs.
Difference between induction motor and synchrous motors?
Induction generators consist of stator windings and rotor windings both of which can be excited or one can be excited at a time so that they can run as singly excited as well as doubly excited machines .and in induction machines rotor consists of ARMATURE winding which is moving and the static FIELD windings is in stator.Whereas synchronous gen. or alternators consists of static stator which consists of ARMATURE winding and moving rotor which consists of FIELD windings. so alternators are only singly excited systems in which the field winding is energised by a DC supply or with a rectifier and AC source and the or prime mover is moved with the help of steam as in thermal powerplant or with the help of water in hydropower plant so it is used in generating units where AC power is generated.
Can 3 phase induction motor work when one phase is failed?
yes the motor will rotate but less then the rated speed and more heat will be desipated
What is rotor speed of the three phase motor?
Efficiency of a motor is the ratio of power supplied to it, to the power produced by it, expressed as a percentage. This varies from motor to motor. It is calculated using the equation: efficiency = ((Pin - Pout) / Pin) * 100A typical power conversion efficiency for an induction motor over ½ HP would be 90%CommentEfficiency is actually the ratio of output power to input power, not the other way around!
