The Study of Third Harmonic Characteristics from Salient Pole Synchronous Generator under Unbalanced Load

A non-linear load draws non-sinusoidal current that consists of frequencies that are multiples of the fundamental frequency. This is the basis of harmonics and it creates distortions when interacting with power systems. In medium voltage systems, loads are always balanced due to the presence of power transformers of delta-wye winding configuration, by which the triplen harmonics currents only circulate at the delta winding of transformer, unable to reach the load. However, in low voltage systems, loads remain unbalanced. Generators are found to be a source of third harmonics and factors influencing the production include slot skew, distribution factor and pitch factor.