- Ideal Transformer Definition: An ideal transformer is defined as a theoretical transformer with 100% efficiency and no losses.
- Core and Copper Losses: In an ideal transformer, there are no core losses or copper losses, ensuring perfect efficiency.
- Purely Inductive Windings: The windings are considered purely inductive, meaning they have no resistance, which is key to the ideal model.
- Magnetizing Current: The primary winding draws a magnetizing current that creates an alternating flux in phase with the current.
- Mutual Induction: The flux in the primary winding induces an EMF in the secondary winding through the core, showing the principle of mutual induction.
Definition of Ideal Transformer
An ideal transformer is defined as a theoretical transformer with no losses—no core losses, copper losses, or any other type of losses. This means it has 100% efficiency.
Ideal Transformer Model
The ideal transformer model is developed by considering the windings of the transformer are purely inductive and the core of the transformer is loss free. Also there is zero leakage reactance of transformer (reactance is the opposition to the flow of current from the circuit element due to its inductance and capacitance).
This means 100% of the flux passes through the core and links with both the primary and secondary windings. While real windings have some resistance causing voltage drops, in an ideal transformer, the windings are considered fully inductive with zero resistance.
Now if an alternating source voltage V1 is applied in the primary winding of that ideal transformer, there will be a counter self emf E1 induced in the primary winding which is purely 180o in phase opposition with supply voltage V1.
To develop the counter EMF (E1) across the primary winding, it draws current from the source to produce the needed magnetizing flux. Since the primary winding is purely inductive, this current lags 90 degrees behind the supply voltage. This current is called the magnetizing current (Iμ).
This alternating magnetizing current Iμ produces an alternating magnetizing flux Φ. The flux is proportional to that current which producing it hence the flux would be in phase with the current. This flux also links the secondary winding through the core of the transformer. As a result, there would be another emf E2 induced across the secondary winding, and this is mutually induced emf as shown in the figure below.
