0
when the pole flux is zero there is no induced emf in the armature conductor of dc machine as a result of this there is no back emf for controlling action so speed become dangerously high or we can say it will be infinite.
Wiki User
∙ 12y ago
Add your answer:
Earn +20 pts
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 happens to d.c motor when Field is weakened in DC?
when the field winding of dc motor opens the flux is zero so the speed is inversely propotional to speed ,so motor runs at dangerous speed...........
What speed motor tends to run when field coil opens?
Zero speed [ 0 rpm]
Performance curve of a single phase induction motor?
The performance curve can be a graph of torque versus speed. The torque is zero at zero speed and also at the synchronous speed. Normally an induction motor operates at 90-97% of the synchronous speed, where the slip is between 10% and 3%. In this region the torque is proportional to the slip. As the torque is increased the speed falls until the motor stalls and the speed drops to zero. Below the stalling speed the torque rises between zero speed and the stalling speed. Because the torque is 0 at 0, a single-phase induction motor needs a separate starting winding fed by a starting capacitor to produce a little positive torque that starts the motor.
Why does a 3 phase motor turn slowly?
An induction motor relies on low-frequency currents induced in the rotor by the difference in speed between the rotor and the rotating magnetic field. At sychronous speed the induced current is zero therefore the torque is also zero.
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 happens to d.c motor when Field is weakened in DC?
when the field winding of dc motor opens the flux is zero so the speed is inversely propotional to speed ,so motor runs at dangerous speed...........
Why is induction motor called asynchronous motor?
We know that relative speed is responsible to induce voltage. If rotor and the rotating field (stator) speed is same, no voltage will induced because relative speed will be zero. For IM relative speed is not zero and it does not move with sync. speed, and so it is called asynchronous motor.
What speed motor tends to run when field coil opens?
Zero speed [ 0 rpm]
When electric flux is zero then electric field is also zero why?
The electric flux depends on charge, when the charge is zero the flux is zero. The electric field depends also on the charge. Thus when the electric flux is zero , the electric field is also zero for the same reason, zero charge. Phi= integral E.dA= integral zcDdA = zcQ Phi is zcQ and depends on charge Q, as does E.
What is slip of synchronous motor?
A synchronous motor runs at synchronous speed, so there is no slip, or zero slip.
Performance curve of a single phase induction motor?
The performance curve can be a graph of torque versus speed. The torque is zero at zero speed and also at the synchronous speed. Normally an induction motor operates at 90-97% of the synchronous speed, where the slip is between 10% and 3%. In this region the torque is proportional to the slip. As the torque is increased the speed falls until the motor stalls and the speed drops to zero. Below the stalling speed the torque rises between zero speed and the stalling speed. Because the torque is 0 at 0, a single-phase induction motor needs a separate starting winding fed by a starting capacitor to produce a little positive torque that starts the motor.
Why does a 3 phase motor turn slowly?
An induction motor relies on low-frequency currents induced in the rotor by the difference in speed between the rotor and the rotating magnetic field. At sychronous speed the induced current is zero therefore the torque is also zero.
What is the slip of synchronous motor?
A synchronous motor runs at synchronous speed, so there is no slip, or zero slip.
Why an induction motor will never run at synhoronous speed?
An induction motor relies on low-frequency currents induced in the rotor by the difference in speed between the rotor and the rotating magnetic field. At sychronous speed the induced current is zero therefore the torque is also zero.
What is the interlace in pole and zero?
its nothing but alternate occurence of pole/zero and zero/pole. ex: f(s)=s*(s+2)/(s+1). here we can easily sense that there is a occurence of zero(s=0),pole(s=-1),zero(s=-2).
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
