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There are two ways of changing the speed of AC motors,by altering the frequency or the number of poles in the motor. An increase in frequency of the supply voltage to the motor will cause it's speed to increase while reducing the frequency will causes the motor speed to drop. This is the method exploited by Variable Speed/Frequency Drive. The second method of changing the number of motor's stator poles is the difficult. The manufacture must design the motor such that the number of the motor's pole in operation can be increased or reduced. Increasing the number of poles increases the stator flux density which decreases the speed. Decreasing the number of poles does the opposite. This method is typically found in two speed motors and it's rarely used compared to VSDs.
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What are convectional and non convectional methods of speed control of a induction motor?
The flux control method is the convectional and the non-convectional method of speed control of an induction motor.
Why is the speed of synchronous motor is more then induction motor?
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.
What in slip speed control?
slip speed control refers to induction machines s=(synchronous speed-motor speed)/synchronous speed by varying slip the machine can be either be operate in generated mode or motor mode
Why do you control the speed of DC motors?
because dc motor is a powerful & dangerous motor it is akiller
Explains why a 3-phase induction motor develops no torque when running at synchronous speed?
When rotor speed becomes equal to Synchronous speed in an induction motor, it means that the slip is zero. Which means that there is no cutting of magnetic lines by rotor bars and hence no torque is generated. To generate Torque, rotor speed should always be less than the synchronous speed. That is why, you must have seen in your dailty life that all induction motors are rated below 3000 RPM(sync speed for a 2 pole machine). Sync speed (Ns) = 120f/P
How does a Variable speed transmission work?
Assume a 3 phase AC Induction motor. The speed of the motor is derived by the formula N = (120/f)/P. N speed, f - frequency, P number of poles. In an induction motor P is fixed by the winding. f system frequency. Variable speed drives change the system frequency so that the speed (N) can be varied. Drive is a power electronic device through which the system frequency can be varied
Speed of the stator field of an Induction motor is?
synchronous speed
What are the advantages of induction motor?
1. Induction motor has high starting torque, therefore use for operate pump which need high starting torque. 2. Induction motor operate on variable speed. 3. It can be used as generator when speed of motor is higher than synchronous speed.
Application of induction motor in industry?
Induction motor used in industries for variable speed machines . Induction motor has always lagging power factor. Less cost compared to syn. Motor.
Difference between induction motor and induction generator?
in case of induction motor the rotor speed is less than synchronous speed giving positive slip but in case of generator the rptor speed is greater than synchronous speed giving negative slip.......
How do you control the speed of a pneumatic motor?
The speed is varied by throttling the air flow into the motor.
What are convectional and non convectional methods of speed control of a induction motor?
The flux control method is the convectional and the non-convectional method of speed control of an induction motor.
If a three phase induction motor runs at a speed greater than synchronous speed?
When an induction motor is pushed over synchronous speed it will become a generator and will deliver power back to the utility.
What is speed controller?
It is used for sensorless motor control. With vf speed control u can control speed of any induction motor.
Why doesn't an induction motor run at synchronous speed?
siyudad
What did mean by standstill in induction motor?
rotor speed = 0
What is vf speed control?
It is used for sensorless motor control. With vf speed control u can control speed of any induction motor.
