the efficiency of transformer is more than alternator, because 1- the alternator have friction and windage loss but in transformer this not occure. 2- in the alternator the flux leak is more than the transformer, because in case of alternator the flux move through the air which is dimagnet and in transformer flux move through silicon steel. 3- in the other hand alternator have dc compound generator for exciation (depend on other electric course 220volt) but in t/f is not need.
A generator, in general.
The changing magnetic flux in the iron core of the transformer induces a voltage in the windings.
when an alternating current apply on primary side of transformer then magnetic flux produced in the iron core of transformer.Then flux link with secondary winding of transformer so that an emf produced in a transformer.
by using an iron core
In a 3-ph transformer the flux also rotates round the 3 cores but you don't see anything moving.
when a load is connected to a transformer current(say I2) flows through secondary coil thus an M.M.F (N2I2) is produced ,this produces the secondary flux. This flux reduces the the main flux induced in the primary & also reduces E.M.F E1 in the primary As a result more current is drawn from the supply. This additional current drawn is due to the load component(say I2' ) This I2' is anti-phase with I2.This I2' sets a flux which opposes the secondary flux & helps the main flux. The load component flux neutralises the secondary flux produced by I2 .The M.M.F N1I2' balances N2I2.Thus the net flux is always at constant level. As practically flux is constant,the core loss is constant for all loads. Hence a transformer is always called a Constant Flux Machine.
when a load is connected to a transformer current(say I2) flows through secondary coil thus an M.M.F (N2I2) is produced ,this produces the secondary flux.This flux reduces the the main flux induced in the primary & also reduces E.M.F E1 in the primaryAs a result more current is drawn from the supply. This additional current drawn is due to the load component(say I2' )This I2' is anti-phase with I2.This I2' sets a flux which opposes the secondary flux & helps the main flux.The load component flux neutralises the secondary flux produced by I2 .The M.M.F N1I2' balances N2I2.Thus the net flux is always at constant level.As practically flux is constant,the core loss is constant for all loads.Hence a transformer is always called a Constant Flux Machine.
Transformer works with varying flux. DC won't create it. Only AC produce varying flux.
The flux is set by the voltage applied to the transformer. In most applications, the voltage is constant, and therefore the flux is constant also.
the efficiency of transformer is more than alternator, because 1- the alternator have friction and windage loss but in transformer this not occure. 2- in the alternator the flux leak is more than the transformer, because in case of alternator the flux move through the air which is dimagnet and in transformer flux move through silicon steel. 3- in the other hand alternator have dc compound generator for exciation (depend on other electric course 220volt) but in t/f is not need.
Yes, the two things that chage the number of flux lines in a transformer(electromagnet) are the number of turns in the windings and the amount of current flow
A generator, in general.
In a Transformer, Core flux is the difference of primary flux and Secondary flux which are opposite to each other in direction. There difference is equal to the no load flux at all loads. So, some of primary flux passes through the core and remaining becomes leakage flux (Because Secondary flux forces it to get out of the core). Same is the case with Secondary flux. Now, flux is directly proportional to Voltage and Current. When Current increases due to increased load (and voltage remains same): Then both primary and secondary flux increase. Because both of them increase, so there difference remains same. And all remaining flux is forced out. Hence leakage flux increases with current, but Core flux remains constant. When Primary Voltage is increased: Then only primary flux increases. So difference of this new increased primary flux and previous same secondary flux increases. Hence Core flux increases with voltage, But leakage flux does not. That's how In transformer core flux depends on voltage whereas leakage flux depends on current.
There are basically 4 major differences :- 1. The windings (both primary and secondary) of an ideal transformer are considered to have zero resistance, hence the transformer is lossless. 2. There is no leakage flux in an ideal transformer. 3. The permiability of the core material in ideal transformer is considered to be tending to infinity and hence the current needed to set up the flux in the transformer is negligible. 4. There is zero hysterisis and eddy current losses in an ideal transformer.
The changing magnetic flux in the iron core of the transformer induces a voltage in the windings.
In DC or direct current, the flux is constant. AC or alternating current is variable.