What is the working principle of induction motor?
What is the working principle of induction motor?
electromagnetic induction
Working Principle of Induction Motor The motor which works on the principle of electromagnetic induction is known as the induction motor. The electromagnetic induction is the phenomenon in which the electromotive force induces across the electrical conductor when it is placed in a rotating magnetic field.
What is induction motor short answer?
The induction motor is fundamentally a transformer in which the stator is the primary and the rotor is short-circuited secondary. At starting, the voltage induced in the induction motor rotor is maximum ( s = 1). Since the rotor impedance is low, the rotor current is excessively large.
What are the starting methods of induction motor?
Induction Motor Starting Methods
- Starting Principle.
- Direct On Line Starter.
- Star-Delta Starter.
- Auto Transformer Motor Starting.
- Rotor Resistance Starter.
What is induction speed?
Since rotation at synchronous speed would result in no induced rotor current, an induction motor always operates slightly slower than synchronous speed. The difference, or “slip,” between actual and synchronous speed varies from about 0.5% to 5.0% for standard Design B torque curve induction motors.
Why is induction motor called asynchronous?
Because it runs at a speed less than synchronous speed. Because induction motor can not rotate at synchronous speed it always rotate less than synchronous speed. in short, induction motor never rotates at synchronous speed so it called asynchronous motor.
What is slip frequency in induction motor?
(3.68), this maximum slip frequency is a function of leakage inductance, and thus, its range depends on the total leakage inductance, X l s + X l r . For a standard induction motor, this value is normally 0.2 p.u., producing a constant power range up to two to three times the rated speed.
What is induction start capacitor?
A Capacitor Start Motors is a single phase Induction Motor that employs a capacitor in the auxiliary winding circuit to produce a greater phase difference between the current in the main and the auxiliary windings. The name suggests that the motor uses a capacitor to start.
Why starter is used in induction motor?
⇒ The starter is a device which is basically used to limit the starting current by supplying reduced voltage to the motor at the time of starting. From the expression of rotor current it can be seen that the current at start can be controlled by : By reducing the supply voltage at the time starting.
What is torque in induction motor?
Torque is the turning force through a radius – with the units Nm in the SI-system and the units lb ft in the imperial system. The torque developed by an asynchronous induction motor varies when the motor accelerates from zero to maximum operating speed.
What is RPM of induction motor?
The synchronous speed is 1500 rpm and the typical full load speed is 1450 rpm. The slip is the difference between synchronous and load speed – 50 rpm.
What is slip formula?
Slip speed is the speed difference between the Synchronous speed and Rotor speed. Slip speed = Synchronous speed – Rotor speed = Ns -N. Slip, s = (Ns – N) / Ns.
What is an induction motor (IM)?
An induction motor (IM) is a type of asynchronous AC motor where power is supplied to the rotating device by means of electromagnetic induction. 2. What Is An Electric Motor? An Electric Motor converts electrical power to mechanical power in its rotor. 3. How To Supply Power To Rotor?
When will the starting torque be maximum in an induction motor?
Starting torque will be maximum when the rotor resistance / phase is equal to standstill rotor reactance / phase. Slip ring induction motor advantages and disadvantages compared to squirrel cage motors? Good running characteristics after external rotor resistances are cut out
What are the disadvantages of induction motors?
One of the main disadvantages of induction motors is that speed control of induction motors are difficult. Hence for fine speed control applications dc motors are used in place of induction motors. Due to advance in power electronics, variable frequency drives using induction motors are used in industries for speed control now a days. 34.
Why are DC motors used in place of induction motors?
Hence for fine speed control applications dc motors are used in place of induction motors. Due to advance in power electronics, variable frequency drives using induction motors are used in industries for speed control now a days.