METHOD FOR REDUCING IRON LOSS OF LAMINATED CORE TRANSFORMER AND LOW IRON-LOSS LAMINATED CORE TRANSFORMER

摘要

PROBLEM TO BE SOLVED: To reduce iron loss of a transformer by advantageously solving the problem of a distortion of magnetic flux waveform in the transformer without deteriorating raw material characteristics. SOLUTION: In a low iron-loss laminated core transformer, a unidirectional magnetic steel sheet and strip, whose magnetic flux density at 800 A/m is 1.88T or higher and in which proportion of eddy-current loss in iron loss in exciting magnetic flux density of a leg of the transformer is 65% or lower, is laminated as an iron core. With a higher harmonics generating device provided on an input side of the transformer, fifth or seventh higher harmonics is superposed on primary voltage in a range where phase difference from the primary voltage is 120 to 240 deg., and the proportion of superposition of higher harmonics is in the range of 5 to 25%.