Hi everyone hope you fine.
1.I'm studying the auto transformer and i have reached where it says apparent power by conduction and induction ..This the first time i see this question .I'm familiar with the power P=VI..If any one could explain this please?
see the two attached files one for the question and the other for the answer

2.the other question is for a three phase transformer .If each single transformer is of 20KVA ..if a three are tied together to form three phase transformer, what is the power that reaches the load if the three of the are configured in delta or wye ??

waiting for help

 

forget about topology and fact that transformer is wired as autotransformer, just ask yourself what is the transformer power rating... that is the amount of power that is transferred by induction (through transformer). in this case that is 100kVA

rest of the power is by conduction (bypasses transformer). here that is 1000kVA

together they produce output power of 1100kVA. this is 11x greater than transformer rating and it is true reason for using autotransformers (small transformer can act as a big transformer if it is used as an autotransformer). the downside is that autotransformers do not offer isolation (which larger transformers can do).

3 x 20kVA = 60kVA regardless of connection (delta or wye). in one case you get lower voltage but larger currents, in the other you get higher voltage but lower current... end result is power is power (is power...)

 

but how to calculate power by induction and conduction???

 

but how to calculate power by induction and conduction???

Do you understand what is meant by those terms?

 

actually no?!! i only know p=vi

 

actually no?!! i only know p=vi

Hi,
Read thru this PDF tutorial.
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