Field Monitoring and Analysis on Vibration and ...

Yin-dong ±660 kV High Voltage Direct Current (HVDC) Power Transmission Project, the first ±660 kV DC transmission project built around the world, is the symbolic project at this voltage level and a major transmission line of Shandong grid. When the HVDC system is operated in monopole ground return mode, the vibration and noise of the ac power transformer will get enhanced during field monitoring. This paper describes the abnormal vibration and noise in detail. By analyzing the abnormal phenomena and monitoring the direct current passing through the neutral point of transformer, this paper shows that the main reason is the monopole grounding operation of Yin-dong DC system. Finally, measures are provided to prevent the occurrence of abnormal vibration and noise of alternating current (AC) power transformers.