Influences of Magnetization Characteristics of the Materials on the Iron Loss of the Wound-Core Type Three-Phase Transformer

Abstract

This paper describes the influences of magnetization characteristics of the materials on the iron loss of wound-core type three-phase transformer. In the analysis, magnetization characteristics are approximated by a Fourier-series, and it is assumed that the eddy current factor is proportional to the time-varying magnetic flux. Moreover harmonic balance method where the zero-phase-sequence and third harmonic components of flux density are taken into consider is used. From the results of numerical analysis, it is shown that iron loss decreases as the ratio of eddy currents loss to iron loss of the material becomes minor. The importance of non-linearity of magnetization characteristics of the materials to reduce iron loss of wound-core type three-phase transformer is also shown. The analytical results agree roughly with the experimental result.

Influence of interlaminar flux between cores on iron loss in three‐legged wound transformer core

“…Up to now, numerical analysis using the finite element method was the mainstream in iron loss analysis of threephase wound-core transformers. [6][7][8][9] In so doing, the main causes of increase in iron loss in three-phase wound-core transformers were thought to be concentration of magnetic flux into the iron core due to magnetic path length F I G U R E 1 Dimensions of model transformer core difference and distortion of flux density waveforms (harmonic superposition) due to three-phase excitation. As regards these causes underlying the loss increase, there were reports on the influence of iron core size and iron core joint structure.…”

“…Up to now, numerical analysis using the finite element method was the mainstream in iron loss analysis of three‐phase wound‐core transformers 6–9 . In so doing, the main causes of increase in iron loss in three‐phase wound‐core transformers were thought to be concentration of magnetic flux into the iron core due to magnetic path length difference and distortion of flux density waveforms (harmonic superposition) due to three‐phase excitation.…”