Impact of Installing Harmonic Filter on Three Winding Transformer

Harmonics often appear in transmission and distribution lines because of the supply of harmonic currents from nonlinear loads. Techniques used to mitigate harmonics can use passive and active harmonic filters. However both types of filters have drawbacks. These filters work optimally to mitigate harmonics at the same bus voltage level, so that if there are other harmonic sources at different bus voltage levels, it has little effect. This paper tries to install a harmonic filter on a three-winding transformer. Primary winding is connected to medium voltage, secondary winding is connected to low voltage, and tertiary winding is connected to harmonic filters. Several scenarios are have to compare the ability of the harmonic filter on a three-winding transformer. Scenario 1 without a filter connected to the electric power system. Scenario 2, the harmonic passive filter is installed on the low voltage side of the nonlinear load. Scenario 3, the harmonic shunt passive filter is installed on the tertiary winding transformer. Harmonic current sources such as nonlinear loads are installed on the low voltage side and the medium voltage side. The results of scenario 3 are able to minimize harmonic distortion to be better than Scenario 2. Scenario 1 is only a case study in this paper.