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When induction motor is switched on the rotor frequency is?
The induction motor rotor has different frequency compared to it's stator. The rotor has slip ( s ) frequency. slip = ( Synchronous speed - rotor speed ) / Synchronous speed Synchronous speed = ( 120 * f ) / P where f = supply frequency to the stator. p = no of poles rotor speed is the actual speed the motor is running. Frequency in the rotor = slip * frequency in the stator At starting rotor speed is zero, so slip is one. Let us take the supply frequency is 50 Hz, then rotor frequency is also 50 Hz at starting. The motor attains speed and runs with its full speed at a point of time. Then let us take the slip is 0.04 then the rotor frequency will be 2 Hz.
What is the torque speed characteristic?
the ratio of the relative speed of stator magnetic field with the speed of rotor, to the speed of rotor is defined as slip. where as in torque slip characteristic is the graph between the speed of the rotor and the torque experienced on the rotor. in the case of induction motor, the torque decreases with the increase in the rotors speed. while in the case of sychronous motor, its different (you check out, because i just forgot about it!! keep smiling!
What happens if the relative speed between the rotating flux of stator and rotor of the induction motor is zero?
if the relative speed of magnetic flux of stator and rotor becomes zero there will be no back emf and eventually the rotor gets zero speed
What will increase when you increase pitch angle rotor blades?
A: The pitch angle is a speed factor and also a torque factor. Increasing or decreasing the angle will effect these factors inversely
What is the effect of starting torque and power factor on double cage and deep bar cage 3phase induction motor?
In double cage and deep bar the tarting torque increases due to skin effect in the rotor wire. So the rotor circuit draw less current than simple circuit that draw around 7-8 times the rated current on starting. Due to skin effect the rotor resistance increases and it provide maximum torque at low speed.
What happen to the rotor speed and rotor current when the mechanical load on an induction motor increases?
rotor speed will decrease....the rotor current wil increase.....
What happens to the rotor speed and rotor current when the mechanical load on an induction motor increases?
rotor speed will decrease....the rotor current wil increase.....
What is damper winding?
The windings behave in the same fashion as the squirrel cage of an induction machine. When rotor speed differs from the stator-side electrical speed, currents are induced in the damper windings. These currents set up a torque that has the effect of pulling the rotor back toward synchronous speed. This is true whether the rotor is spinning above synchronous or below synchronous speed. When the rotor is spinning at synchronous speed (i.e. zero slip), no currents are induced in the damper windings. Damper windings are commonly found on large, low-speed, salient pole machines, where there is a tendency to have inadequately damped rotor oscillations without the amortisseurs.
When induction motor is switched on the rotor frequency is?
The induction motor rotor has different frequency compared to it's stator. The rotor has slip ( s ) frequency. slip = ( Synchronous speed - rotor speed ) / Synchronous speed Synchronous speed = ( 120 * f ) / P where f = supply frequency to the stator. p = no of poles rotor speed is the actual speed the motor is running. Frequency in the rotor = slip * frequency in the stator At starting rotor speed is zero, so slip is one. Let us take the supply frequency is 50 Hz, then rotor frequency is also 50 Hz at starting. The motor attains speed and runs with its full speed at a point of time. Then let us take the slip is 0.04 then the rotor frequency will be 2 Hz.
What is a rotor hub?
Rotor hub links the blades to the low-speed shaft
What is the torque speed characteristic?
the ratio of the relative speed of stator magnetic field with the speed of rotor, to the speed of rotor is defined as slip. where as in torque slip characteristic is the graph between the speed of the rotor and the torque experienced on the rotor. in the case of induction motor, the torque decreases with the increase in the rotors speed. while in the case of sychronous motor, its different (you check out, because i just forgot about it!! keep smiling!
What happens if the relative speed between the rotating flux of stator and rotor of the induction motor is zero?
if the relative speed of magnetic flux of stator and rotor becomes zero there will be no back emf and eventually the rotor gets zero speed
Why do helicopters fly so slow?
What is the limiting factor for helicopter speed you ask? What happens to the rotor as the velocity of the helicopter increases? The relative speed of the tips of the rotors changes because of the wind speed. On the advancing side of the rotor the speed increases by the speed of the helicopter. On the retreating side of the rotor the speed decreases by the speed of the rotor. One of two things happens as the helicopter reaches a high speed: A: If it is a large rotor, the advancing blade will reach the sound barrier and sap energy from the rotor, slowing it. Significant damage may occur to the helicopter. B: If it is a smaller rotor, the retreating blade will slow to the point where stall occurs, and the helicopter will be forced into a turn while losing altitude and decreasing speed, then it will usually recover if altitude permits. Option B can be mitigated by increasing rotor RPM at higher speeds. In this case the rotor speed becomes the limiting factor, as the centrifugal forces at the root of the blade are quite incredible. Carter
How can vary the induced voltage in rotor?
You can vary the induced voltage by varing the speed of the rotor.
What happens to the rotor speed and rotor current when the mechanical load on an induction motor increase?
whenever the load increases,the current drawn by the motor to do or to fulfill the required energy to the load. so the current will increase generally.Increase in load will cause the full utilization of motor,so speed of rotor will decrease.
Why sleep is occurs in three phase induction motor?
Slip is the relative difference between the speed of the rotating magnetic field of the stator windings and the speed of the rotor. The rotor must always run at a speed lower than the synchronous speed otherwise the rotor windings will not be cut by the magnetic field and hence no induced emf,no torque and the rotor will stand idle.
What are the Types of alternators based on rotor construction?
Types of rotor-Salient pole or projected typeNon salient pole or cylindrical typeSalient type is used for low speed or medium speed motor where non salient type is used for high speed rotor.
