Causes of harmonics in transformers

Harmonics are the result of nonlinear loads that convert AC line voltage to DC. Harmonics flow into the electrical system because of nonlinear electronic switching devices, such as variable frequency drives (VFDs), computer power supplies and energy-efficient lighting.

1. How does harmonics affect transformers?
2. Can transformer produce harmonics?
3. What causes 5th and 7th harmonics?

How does harmonics affect transformers?

The primary effect of harmonic currents are the additional power losses in transformer components, which result in increase in generated heat, as well as reduction of transformer's life-expectancy.

Can transformer produce harmonics?

Transformers:Harmonics in transformers cause an increase in the iron and copper losses. Voltage distortion increase losses due to hysteresis and eddy currents and causes overstressing of the insulation material used. The primary effect of power line harmonics in transformer is, thus the additional heat generated.

What causes 5th and 7th harmonics?

Magnetic cores, such as transformer and rotating machines that require third harmonic current to excite the iron. Synchronous machines (winding pitch produces fifth and seventh harmonics)