In addition to the operation of transformers on the sinusoidal wave provides, the harmonic behavior becomes vital because the size and rating of the power transformer will increase. The eﬀect of the harmonic currents are:
- Extra copper losses because of harmonic currents.
- Increased core losses.
- Increased electromagnetic interference with communication circuits.
On the opposite hand the harmonic voltages of the transformer cause:
- Increased dielectric stress on insulation
- Electro static intervention with communication circuits.
In the present times a bigger alertness is generated by the issues of harmonic voltages and currents created by non-linear masses just like the power electronic converters. These mix with non-linear nature of electrical device core and turn out severe distortions in voltages and currents and increase the facility loss. Therefore the study of harmonics is of nice sensible signiﬁcance within the operation of transformers. The discussion here is conﬁned to the harmonics generated by transformers solely.