The frequency of induced e.m.f in the armature conductors depends upon speed and the number of poles. Let, N = rotor speed in r.p.m P = number of rotor poles. f = frequency of induced e.m.f in Hz. Consider a stator conductor that...
Archive - November 2021
An alternator has 3 phase winding on the stator and D.C field winding on the rotor. Stator It is the stationary part of the machine and is built up of sheet-steel laminations having slots, on its inner periphery. A 3 phase...
The machine which produces 3 phase power from mechanical power is called an alternator or synchronous generator. An alternator works on the same fundamental principle of electromagnetic induction as a D.C generator, when the flux...
The stator winding of a single phase induction motor is connected to single phase AC supply. Then a magnetic field is developed in the stator whose axis is always along the axis of stator windings. With alternating current in the...
The single phase induction motors are small motors. These motors have power rating in fractional horse power range. These motors are used in homes, offices, shops and factories. They provide motive power for fans, washing...
The speed of an induction motor can be controlled by two major methods. They are: Stator side control Rotor side control The first method is applicable for both squirrel-cage and wound-rotor motors. The second method can be...
When 3- Φ Induction motor is switched on at normal supply voltage, heavy current “ill flow through the motor because at the time of starting, there is no back emf. An induction motor, when directly switched on, takes five...
Three phase induction motors are extensively used for electric drives. The main advantages which make it so popular for industrial use are: It is simple and extremely rugged construction. High reliability. Low cost. Its ability...
The generation of electric power is three-phase in nature and the generated voltage is 13.2kV, 22kV or higher. Transmission of power is carried out at high voltages like 132kV or 400kV. Before transmission, it is required to...
The ordinary or commercial efficiency of a transformer is defined as the ratio of output power to the input power. There are certain types of transformers whose performance can not be judged by this efficiency. For instance...
