What is the basic principle of three-phase induction?
The working of the three-phase induction motor is based on the principle of electromagnetic induction. When three-phase stator winding of an induction motor is energized from a 3 phase supply, a rotating magnetic field is set up which rotates around the stator at synchronous speed (Ns).
What is the basic construction and operating principle of induction motor?
Basic working principle of an Induction Motor. In a DC motor, supply is needed to be given for the stator winding as well as the rotor winding. But in an induction motor only the stator winding is fed with an AC supply. Alternating flux is produced around the stator winding due to AC supply.
What is the basic principle of a poly phase induction motor?
A polyphase induction motor consists of a polyphase winding embedded in a laminated stator and a conductive squirrel-cage embedded in a laminated rotor. Three-phase currents flowing within the stator create a rotating magnetic field which induces a current and consequent magnetic field in the rotor.
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 the working principle of synchronous motor?
The principle of operation of a synchronous motor can be understood by considering the stator windings to be connected to a three-phase alternating-current supply. The effect of the stator current is to establish a magnetic field rotating at 120 f/p revolutions per minute for a frequency of f hertz and for p poles.
What is electromagnetic induction principle?
Faraday’s Principle of Electromagnetic Induction states that the emf induced in a loop due by a changing magnetic flux is equal to the rate of change of the magnetic flux threading the loop.
What are the parameters of induction motor?
One of the most common sets of parameters representing an induction machine model consists of the following five parameters: stator resistance Rs, rotor resistance Rr, stator leakage inductance L7s, rotor leakage inductance L7r, and magnetizing inductance Lm [1,5,10–12].
What is the function of induction motor?
An induction motor 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. An induction motor can therefore be made without electrical connections to the rotor.
What is the principle operation of a three-phase motor?
A 3 phase induction motor derives its name from the fact that the rotor current is induced by the magnetic field, instead of electrical connections. The operating principle of a 3 phase induction motor is based on the production of a rotating magnetic field (r.m.f.).
What is slip in induction motor?
“Slip” in an AC induction motor is defined as:
As the speed of the rotor drops below the stator speed, or synchronous speed, the rotation rate of the magnetic field in the rotor increases, inducing more current in the rotor’s windings and creating more torque. Slip is required to produce torque.
What are induction motors made of?
The stator frame consists of laminations of silicon steel, usually with a thickness of about 0.5 millimetre. Lamination is necessary since a voltage is induced along the axial length of the steel as well as in the stator conductors.
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 slip of motor?
In an electrical coupling, slip is defined simply as the difference between the speeds of the two rotating members. In an induction motor, slip is a measure of the difference between the machine’s synchronous speed and its shaft speed.
What is permanent magnet principle?
Like an induction motor, a permanent magnet motor has a Stator configured to provide a number of poles, usually for a 3-Phase supply. However, instead of containing Rotor bars, the Rotor has magnets mounted on, or embedded in, the laminations.