The Design And Construction Of 2kva Inverter

3.1.13 TRANSFORMER
A transformer is not an energy conversion device, it is a device that changes AC electrical power at one voltage level into AC electrical power at another voltage level through the action of magnetic field, without a change in frequency. It can either be step-up or step-down transformer.
The transformer winding have two main parts namely. The primary and secondary windings. Therefore transformer can be defined as a non-rotation electromagnetic device that transform electrical energy at one level to another level through the help of magnetic coupling i.e the principle of mutual induction. 

OPERATION OF TRANSFORMER  
The operation principle of a transformer is very simple; it depends upon Faraday’s law of electromagnetic induction. Hence, mutual induction between two or more winding is responsible for transformation action in an electrical transformer. When the primary winding is supply by an alternating electrical source. The alternating current flow through a primary winding and produce magnetic flux or alternating flux which lead to a secondary winding and so as electromotive force (EMF) is induced according to Faraday’s law of electromagnetic induction which state whenever there is charge in a magnetic flux linked with a circuit, an electromotive force is induced, the strength of which is proportional to the rate of change of flux linked with the circuit i.e the induced EMF is directly proportional to the rate of change of magnetic flux linking the magnetic flux circuit.(BEDOFORD,B.D.,HOFT,R.G,et al.(1964) principle of inverter circuit New York, John Willey).
As the magnetic flux varies sinusoidal, ï„‚=ï„‚ max sinwt, then the basic relationship between induced EMF (E), in a coil winding of N turn is given by:

       Where E is the inductive e.m.f
N1     =    number of turns in primary winding
N2    =    number of turns in secondary winding
di    =    change in magnetic flux
dt    =    change in time