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What happen if we do the 3 phase winding in rotor of induction motor and give the 3 phase supply only stator winding?
This is how an induction motor normally works, hence the name. The supply voltage is connected to the stator winding(s) and a current is induced in the rotor. A synchronous motor, on the other hand, will have current supplied to the rotor through slip rings and brushes. The rotor current is generally supplied as DC though, or else rectified in the rotor.
What is locked rotor in three phase induction motor?
A motors locked rotor current is the same as the motors starting current. This is the point where the voltage is applied to a non rotating motor, time cycle zero. Because the motor is not rotation and generating a back EMF to oppose the inrush current, the current will go as high as 6 times the running current of the motor.
What causes the current to decrease as an induction motor accelerates?
The current in an induction motor decreases as it accelerates due to reduced rotor impedance and increased back EMF. As the motor speeds up, the rotor reacts with the rotating magnetic field produced by the stator, causing a decrease in the current needed to maintain acceleration. This decrease in current helps to improve the motor's efficiency and reduce energy consumption.
How does an induction motor start?
The emf induced in the rotor depends upon the rotor frequency which further depends on relative speed between rotor and synchronous speed of rotating magnetic field. The relative speed at the time of starting or standstill is maximum and hence large emf in induced in rotor conductors or winding due to which very high current flows in rotor which is generally 5 to 7 times of the full load or running current of an indication motor. The starting current, sometimes called inrush current will be 8-10 times higher than the motor's rated current because the motor is at rest. When at rest, the motor appears to be a transformer, with it's secondary winding short circuited, i.e. the rotor winding or squirrel cage is a closed circuit. This results in a low impedance to the system voltage and the motor has a "locked rotor" current of typically 6 times full load current, but also up to 8 and sometimes 10 times current. This starting value is independent of any load attached, however, the inertia of the motor and load has to be overcome. This is especially true when the motor is connected to a load, like a conveyor belt with product on it. The larger the inertia, the longer the motor takes to reach full speed. As the motor accelerates, part of the starting current power overcomes this inertia and is conveted to kinetic energy. The remaining power of the starting current heats the rotor, up to possibly 250 deg C for a "long" start (20 seconds!!). During the first couple of cycles of AC current, transient currents make some of the phases have higher assymetrical values, which can cause nuisance tripping of the supply breakers to the motor, when protection settings are too low! Equation for current: I = P / cos phi / ( 1.732 * V), (cos phi can be 0.3 during starting). V (voltage) stays pretty much constant, therefore I (current) must rise (but is limited to the locked rotor value for the specific motor) as P (power) is required to start the motor and to keep it running. Some voltage drop will occur for most power systems during a motor start, thus with a constant locked rotor impedance, the starting current will reduce proportionally. I start = V / 1.732 / Z (locked rotor) for a three phase motor. (Z is fixed) When nearly full running speed is reached, the current drops rapidly to full load current or less, depending on the actual load attached. -Don't forget to recommend Kevlarster if you like this answer!
Formula for rotor speed on a cage rotor induction motor?
The formula to calculate the rotor speed (N_r) of a cage rotor induction motor is given by: N_r = (120 * f) / P, where f is the supply frequency in Hz and P is the number of poles in the motor. This formula assumes the motor is running at near synchronous speed and neglects slip.
What is induction motor?
Induction motor is an AC electric motor which uses electromagnetic induction to induce the electric current in the rotor to produce torque.
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 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.....
Does induction motor has rotor winding?
Yes, the induction motor has a rotor winding. It is usually one turn, shorted. This is how the magnetic fields generated in the stator induce a current in the rotor, which subsequently generates a torque from the opposing magnetic fields, stator to rotor.
Why induction motor current increase when load increase?
The slip is proportional to the load torque in an induction motor. This can also be seen as a reduction in speed causing extra current to be induced in the rotor to supply the increased torque.
What happen if we do the 3 phase winding in rotor of induction motor and give the 3 phase supply only stator winding?
This is how an induction motor normally works, hence the name. The supply voltage is connected to the stator winding(s) and a current is induced in the rotor. A synchronous motor, on the other hand, will have current supplied to the rotor through slip rings and brushes. The rotor current is generally supplied as DC though, or else rectified in the rotor.
What is the useful of open end winding of induction motor?
Standard induction motor has a closed squirrel cage rotor, where as open ended induction motor has split phase 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.
The part of an ac induction motor that turns is called?
The part of an AC induction motor that turns is called the rotor. The rotor is located inside the stator, which is the stationary part of the motor. When alternating current flows through the stator windings, it creates a rotating magnetic field that induces current in the rotor, causing it to spin and produce mechanical output.
What is the principle of 3 phase induction motor?
When three phase supply is given to the three phase stator winding of the induction motor,a rotating magnetic field is developed around the stator which rotates at synchronous speed.This rotating magnetic field passes through the air gap and cuts the rotor conductors which were stationary.Due to the relative speed between the stationary rotor conductors and the rotating magnetic field,an emf is induced in the rotor conductors.As the rotor conductors are short circuited, current starts flowing through it.And as these current carrying rotor conductors are placed in the magnetic field produced by the stator, they experiences a mechanical force i.e. torque which moves the rotor in the same direction as that of the rotating magnetic field. the induction motor can't run at the synchronous speed because at synchronous speed the induction motor can not develop any torque to move the rotor from its stationary position.
What is locked rotor in three phase induction motor?
A motors locked rotor current is the same as the motors starting current. This is the point where the voltage is applied to a non rotating motor, time cycle zero. Because the motor is not rotation and generating a back EMF to oppose the inrush current, the current will go as high as 6 times the running current of the motor.
What does the Induction motor do that Nikola Tesla invented?
The induction motor is an alternating current motor that Nikola Tesla invented. It generates motion by inducing a current in a rotor when coupled with an alternating current power source. This design allows for a simpler and more efficient electrical motor compared to direct current motors.
