A transformer (Fig. (A)) is a static device that consists of two or more stationary electric circuits interlinked by a common magnetic circuit to transfer electric energy between them. The transfer of energy from one circuit to another takes place without a change in frequency. What are Step-up and Step-down Transformers? This is a very […]
POWER SYSTEM PROTECTION
Fuse: It is a device used in circuit for protecting electrical equipment against overloads and/or short circuits. As we can see in Fig.(A) when high current flows through the system then heat produced melts the wire of fuse and thereby open the circuit. If “I” (current) flows through fuse wire HEAT PRODUCED = (I2 *R)*T […]
PRINCIPLE OPERATION OF INDUCTION MOTOR II
In Squirrel Cage Induction Motor the rotor has conductors just like damper bars and as we can see in Fig A same number of poles are induced in the rotor as the stator which is an essential condition for Torque production. In Wound Rotor Induction Motor winding on the rotor should be such that same […]
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. (1) Alternating flux is produced around the stator winding due to AC supply. This alternating flux revolves with synchronous speed. […]
INDUCTION MACHINES
Induction machine is a singly excited AC machine in which supply is only connected at 1 winding and other winding receives energy from first winding by means of mutual induction. The stator of induction machine is excited by means of 3 phase AC supply and the rotor receives its energy from the stator through the […]