Elimination Technique to Identify the Harmonic Distortion Under Unbalanced Load

Unbalanced voltage and current in distribution networks is undesirable, as it can cause serious problems for three-phase loads and generators. Unbalanced conditions generate excessive voltage and current harmonics, which may damage utility and customer equipment. Therefore, in order to participate in the development of the correction methods, the first step is to quantify and detect the harmonic degrees. This paper develops a measurement method to identify harmonic degrees by studying harmonic indices under unbalanced settings. Twenty distribution transformers were used as a case study to assess the new indices. The results of the new measurement method are consistent with a relevant reference in the literature, and the findings from two methods show that the proposed method has high performance.