一种电流互感器二次回路多点接地在线监测装置及其监测方法的研究

Research on a Multi-point Grounding Online Monitoring Device of Current Transformer Secondary Circuit and Its Monitoring Method

针对火力发电厂电流互感器二次回路随着时间的推移容易发生两点或多点接地,造成差动保护误动或拒动的现象,研制了一种电流互感器二次回路接地点监测装置,通过PLC编程控制程序、继电器合理配合,实时在线监测发电厂电流互感器二次回路接地点的接地情况,一旦发生二次回路两点或多点接地时发送报警信号,工作人员及时发现和消除安全隐患,避免发生区内故障时保护拒动、发生区外故障时保护误动的情况,保障机组的安全稳定运行。

Over time,the secondary circuit of the current transformer of the thermal power plant is prone to grounding at two or more points,resulting in the phenomenon of misoperation or refusal of differential protection.In order to solve this problem,a ground point monitoring device for secondary circuit of current transformer is developed.Through PLC programming control program and reasonable coordination of relays,real-time online monitoring of the grounding situation of the secondary circuit grounding point of the current transformer of the power plant is carried out.Once the secondary circuit grounding of two or more points occurs,an alarm signal will be sent.Then the staff will identify and eliminate the hidden danger in time,avoid protection refusal when faults occur inside the area,and prevent misoperation when faults occur outside the area to ensure safe and stable operation of the unit.