油浸式平波电抗器重瓦斯保护误动分析及防治措施

Malfunction Analysis on Buchholz Relay of Oil-immersed Smoothing Reactor and Countermeasures

介绍了某换流站两起油浸式平波电抗器重瓦斯保护误动经过,对瓦斯继电器的结构、校验方法及现场测试进行了分析说明,认为平波电抗器在直流系统发生换相失败时,其内部受到大电流的热效应产生油流涌动,并伴随瓦斯继电器本体振动,进而导致重瓦斯保护动作。最后,针对重瓦斯保护动作机理提出了相关防治措施和方法,有效地降低了瓦斯继电器误动的可能性,提升了跨区直流输电系统的运行可靠性。

Two malfunction processes of the Buchholz relay of an oil-immersed smoothing reactor are described, and the structure, calibration methods and field tests of Buchholz relay are analyzed. It is concluded that when phase conversion of the DC system fails, oil flow surge due to thermal effect of large current happens in the smoothing reactor and vibration of the Buchholz relay body occurs, causing action of Buchholz relay for heavy gas protection. In addition, some countermeasures are offered according to the action mechanism of the Buchholz relay for heavy gas protection to reduce malfunction possibility of the Buchholz relay and enhance the operational reliability of cross-region HVDC transmission system.