Misconception about Transformer
Naveed Khan (M.Sc., B.Sc. Engg., (PMP)?)
Deputy General Manager.
Normally it is considered that Transformer is Non-Ohmic or Non-Linear because when you increase voltage, current is reduced which is Non-Ohmic. To say it seems like it is true/ a fact but we need to go a bit in depth of transformer to elaborate this thing.
First of all the question is that what is the definition of a transformer. I would not define it conventionally but I would define it in my own way, Transformer is the combination of two electric circuits magnetically coupled with each other via mutual inductance. In order to explain above behavior of transformer, first I would like to explain prerequisites of Ohm law.
When you apply Ohm’s law following conditions must be met,
1.?????Input power is not constant i.e. when u increase voltage, it increases current of the circuit and thus power, P = VI, is increased and vice versa. ?
领英推荐
2.?????Ohm’s law, when studied, is always considered on ONE ELETRIC CIRCUIT AT A TIME. One can’t confuse two circuits while dealing Ohm’s Law.
In case of transformer, when we talk about voltage and current of a transformer we should observe parameters (voltage and current) of specific side (either LV or HV side). We should not confuse VOLTAGE of LV side with HV side CURRENT or we should not confuse VOLTAGE of HV Side with LV Side CURRENT. They are two separated electric circuits.
V(hv)/V(lv) = I(lv)/I(hv) __________hv shows high voltage side and lv shows low voltage side
The above formula is based on condition when Power to a transformer is fixed. 2nd thing here confusion (among different people) is that they confuse two electric circuits. In this, case when u increase the above Turn Ratio i.e. N (hv) > N(lv), V(hv) voltage is increased and I(hv) current is reduced because power is constant. If you increase voltage to a transformer, current on the same side will increased linearly and moreover the same impact will happen on the other side i.e. will follow Ohm's Law. So, transformer is Ohmic.?