Harmonic Generation-1

Harmonics are generated not only by nonlinear electronically controlled loads, but also by the conventional power equipment, such as transformers, motors and generators. Harmonics in transformers originate as a result of saturation, switching, high-flux densities, winding connections and grounding. It can be said that power transformers generate very low levels of harmonic currents in steady-state operation, and the harmonics are controlled by design and transformer winding connections. All commercially available harmonic analyses programs eliminate triplen harmonics on the power lines feeding the delta windings and consider the phase shifts in the transformer windings to alter the phase angle of harmonics on the primary side of the transformer. For delta connected transformers the ferroresonance can occur for less than 100 ft of cable. Power capacitor in appropriate system configurations, when applied as filters, will limit the harmonics in the power systems, by acting as a sink to the desired harmonics.