Diagnosis and Analysis of Abnormal Grounding Current in Converter Transformers

The online monitoring device for transformer core and clamp grounding current can accurately monitor the changes in grounding current of the core and clamp, and timely and effectively detect whether there are multiple grounding situations and other abnormal conditions in the transformer core and clamp. It has been widely used in the power system and gradually replaces the manual inspection of transformer core and clamp grounding current. However, after the installation and operation of such online monitoring devices in the converter station, it was found that there were problems such as unreasonable design and incomplete performance testing plans. This article, by measuring and analyzing the grounding current waveform of the converter transformer core and clamp, identifies the reasons for the abnormal measurement results of the grounding current online monitoring devices for the iron core and clamp during the installation and operation of the converter, and proposes corresponding measures, A higher precision harmonic detection technology and laboratory performance detection method have been proposed at the same time.