| 摘要 |
PROBLEM TO BE SOLVED: To precisely and easily evaluate the amount of DC polarization and its polarity of a transformer, by estimating condition of magnetic flux passing through an iron core by the exciting current of the transformer. SOLUTION: An apparatus for evaluating DC polarization which evaluates the amount of the DC polarization and its polarity of a converter transformer 2 consisting of an iron core with at least one gap cutting a magnetic path, a converter side winding 21 connected to a power converter 1, and an alternating current side winding 22 connected to a load or an electric power system 3 is provided with means 61 and 62 which detect current waveforms I1 and I2 flowing through converter side and alternating current side windings of the converter transformer 2, a means 41 which performs A/D conversion of a current waveform signal, a means which calculates an exciting current waveform I0 of the converter transformer 2 from an A/D converted current waveform signal, a means which calculates time intervalsΔt1 andΔt2 of positive and negative sides of the exciting current waveform I0 , and a means which evaluates the amount of the DC polarizationϕdc and its polarity of the converter transformer 2 by the time intervals.
|
