Characteristics of Fifth and Seventh Harmonics in Japanese Electric Power Distribution System

Abstract

Many transformers of customers such as buildings connected to medium voltage of distribution network in Japan mainly use Y - Δ transformers. On the other hand, low voltage single-phase load uses line to line voltage. From this fact, it is expected that the fifth and seventh harmonics generated from these customers will cancel each other, but these conditions have not been well understood so far. In this paper, characteristics of the fifth and seventh harmonics will be explained with reference to the literature on harmonics. In addition, from the realities of these fifth and seventh harmonic currents, a harmonic current model is created and the effect of the current harmonic limit value is considered.