直流接地事故分析及应对策略

Analysis and Countermeasures of DC Grounding Fault

通过分析某电厂发生备用变压器瓦斯保护误动作的过程,说明了该事故的直接原因是直流系统接地。在事故排查过程中,发现保护装置输入光耦动作值小,直流绝缘检测系统不符合规范等问题。针对此次事故给出整改意见,提出了在设备检修、管理中需注意的一些问题。

By analyzing a malfunction on gas protection of a standby transformer in a power plant, this paper points out that the direct cause of the accident is the grounding of DC system. In accident investigation, this paper finds that the input optocoupler action value of protection device is small and the DC insulation detection system does not meet the standard. At last, this paper gives the rectification that needs to pay attention in equipment maintenance and management.