Prediction of magnetising current waveform in a single-phase power transformer under DC bias
Prediction of magnetising current waveform in a single-phase power transformer under DC bias
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DOI：
10.1049/iet-smt:20060031
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发表时间：
2007-01-01
影响因子：
1.4
通讯作者：
Seitlinger, W.
中科院分区：
文献类型：
--
作者：
Biro, O.;Augerhofer, S.;Seitlinger, W.
直流（DC）流过变压器绕组的接地中性点，在磁化电流中产生直流分量。由于非线性，该电流的波形严重失真。本文提出了一种基于变压器有限元分析的方法，可以根据给定的绕组电压和直流偏置的大小来预测磁化电流的波形。在静态条件下，确定了绕组的磁链与磁化电流之间的关系。借助这条磁通-电流曲线，建立了波形以及磁化电流直流分量与偏置磁通的关系。因此，产生给定直流分量的磁通偏置可以通过适当的迭代技术得到，得到具有规定直流值的磁化电流波形。在单相变压器上测量了不同电压和直流偏置下的电流波形。计算波形与实测波形吻合较好。
Direct current (DC) flowing through the earthed neutrals of transformer windings causes a DC component in the magnetising current. Owing to non-linearity, the waveform of this current is strongly distorted. A method based on the finite element analysis of a transformer is presented that is capable of predicting the waveform of the magnetising current with the voltage of the winding as well as the magnitude of the DC bias given. The relationship between the flux linkage of the winding and the value of the magnetising current is determined, with static conditions assumed. With the aid of this flux-current curve, the dependence of the waveform and thus of the DC component of the magnetising current upon the bias flux is established. Hence, the flux bias yielding the given DC component is obtained by suitable iterative techniques, arriving at the waveform of the magnetising current with the prescribed DC value. Measurement of the current waveform at various voltages and DC bias has been carried out on a single phase transformer. The computed waveforms agree well with the measured ones.