Leakage flux is the magnetic flux that does not link both the primary and secondary windings of a transformer. It is caused by the leakage of magnetic field lines from the primary winding to the surrounding air or from one winding to another.
Leakage flux can cause energy losses in a transformer, leading to a decrease in efficiency. This is because the leakage flux produces eddy currents in the conducting parts of the transformer, which dissipate heat and reduce the overall efficiency.
The amount of leakage flux in a transformer is influenced by various factors, including the number of turns in the windings, the distance between the windings, the core material, and the shape and size of the core.
One way to reduce leakage flux is by using a tightly wound coil with a high number of turns. This reduces the distance between the windings and decreases the amount of flux that escapes. Additionally, using materials with low magnetic permeability for the transformer core can also help reduce leakage flux.
Leakage flux is considered an undesirable phenomenon in a transformer because it leads to energy losses and reduces efficiency. However, some amount of leakage flux is necessary for the proper functioning of a transformer, as it helps to maintain the balance between the primary and secondary windings.