Different Ways to Improve Starting Torque of A.C. Induction Motors

Formula of starting torque of induction motor

A.C. induction motor starting torque is very low as compared to DC motor starting torque.Also, during acceleration the induction motor produces torque pulsation. As a result , there is noise and vibration in the machine during the starting of the motor. The induction motor should meet the  starting torque demand of the driven equipment in … Read more

Why do 3 phase induction motors not need a neutral?

RYB phase sequence

3 Phase induction motor is a balanced three phase load. Therefore, the induction motor draws a balance current if the supply voltage and the impedance of the motor are balance. The balance current in all three phases of the motor  leads  no current in the neutral. Therefore, there is no need of neutral in the … Read more

Why can’t an Induction Motor run at synchronous speed?

The induction motor can’t run at synchronous speed because it is not possible to run the motor without load. Even the motor is at no load, there would be core loss,copper loss and air friction loss.In a nut shell, the motor slip can not be zero in any case. Therefore, running of induction motor at … Read more

What is the slip value of a 3-phase induction motor at synchronous speed and starting speed?

When the stator of the induction motor is fed three phase supply, the synchronous rotating field is generated. The flux generated in the stator gets linked to the rotor conductor. The voltage is induced in the rotor if the relative speed difference exist between the synchronous speed(Ns= 120f/P) and the actual rotor speed. The difference … Read more

The resistance of L length wire is R. If half of its length stretch such as the total length becomes 2L what will be the final resistance?

The resistance of L length wire is R. The resistance of L/2 length wire is R/2 Now the other L/2 length of the wire is stretched to length X to have full length of conductor 2L L/2 +X = 2L X= 3/2 L The length of the stretched conductor is 1.5 L. Length of conductor … Read more