What is the magnetizing current in induction motor?

In order to set up magnetic flux inside the air gap of induction motor, large magnetizing current is required. During no load, the current drawn by induction motor is 30\%-60\% of rated current whereas current drawn by transformer during no load is 2\%-6\%.

What is magnetising current?

[′mag·nə‚tiz·iŋ ‚kə·rənt] (electricity) The current that flows through the primary winding of a power transformer when no loads are connected to the secondary winding; this current establishes the magnetic field in the core and furnishes energy for the no-load power losses in the core.

What is the value of magnetising current?

1 Answer. Magnetising current will be practically irrelevant in a good mains transformer design. As it’s in quadrature to the load current, a mag current of 10\% of the full load will increase the full load current of the transformer by 1\% (Pythagorus). 10\% is a very conservative estimate, it will typically be smaller.

How do you find the stator current of an induction motor?

The stator current is calculated by dividing the phase voltage by the equivalent complex impedance of the entire circuit shown. The speed of the stator magnetic field in radians per second is 4xPixf/poles. The speed of the rotor (mechanical speed) is the speed of the stator magnetic field minus the slip.

What is magnetising current in CT?

A certain amount of current is drawn by a transformer from the source connected to it primary even when no load is connected to its secondary. A part of this current is used to create flux in the transformer core. This current is known as magnetization current.

How do you find the magnetising current?

For a solenoid, magnetizing current is defined to be the extra current that would be needed to restore the flux if the high-permeability core were removed. For a transformer it’s the actual primary current with the secondary open. It’s the current needed to establish the flux given by Faraday’s emf = -N d phi/dt.

How is short circuit current calculated in an induction motor?

(1/4) = 0.25 per unit based on motor rated apparent power (kVA) and voltage. The “four times rated current” approximate short-circuit contribution is determined by assuming a “typical” connected group having 75 percent induction motors at 3.6 times rated current and 25 percent synchronous motors at 4.8 times rated.

What is the magnetizing current of a power transformer?

Magnetizing inrush current in transformer is the current which is drown by a transformer at the time of energizing the transformer. This current is transient in nature and exists for few milliseconds. The inrush current may be up to 10 times higher than normal rated current of transformer.

Why magnetizing current is required in an induction motor?

See basically , in an Induction Motor magnetizing current is required to set up necessary rotating magnetic field. This is represented by magnetizing reactance in the equivalent circuit diagram of IM. An inductor doesn’t absorbs or supplies real power. The only power associated with inductors is the reactive power.

What happens if there is no magnetic flux in a motor?

Without magnetizing current, the magnetic field can’t be generated, and the motor operation is not possible. The stator winding is inductive in nature and when applied AC to the stator, it draws current that lags the applied voltage. The current required to establish magnetic flux in the air gap of the motor.

What is an induction motor?

An induction or asynchronous motor is an AC electric motor in which the electric current in the rotor needed to produce torque is obtained by electromagnetic induction from the magnetic field of the stator winding…

How to calculate iron loss of induction motor?

Iron loss component of current Iw= Total no load losses / (3 x phase voltage) No load Power Factor: No load power factor of an induction motor is very poor. As the load on the machine increases the power factor improves. No load power factor can be calculated knowing the components of no load current.