直流操作回路在线监视与预警

On-line Monitoring and Warning of DC Operating Circuit

有效识别直流操作回路硬件缺陷,挖掘其存在的隐性故障,对保证继电保护可靠动作具有重要意义。为此,从直流操作回路的工作原理和特点出发,针对其存在的主要缺陷,提出了1种实用可行的直流操作回路在线监视与预警方法。该方法通过在线监测跳、合闸回路流过的电流来识别直流操作回路存在的接触不良、回路断线问题,同时利用时间继电器来在线监视跳、合闸回路的工作状况,实现对跳、合闸回路元件的保护。然后针对实际线路保护装置,讨论了监视装置相关参数的整定方法及元件的选型。最后以某220 k V线路保护为例,对所提出的监视与预警方法进行了实验分析。实验结果表明:该方法既能有效识别直流操作回路存在的接触不良、回路断线问题,实现对直流操作回路的完整性全工况监视,又能在线监视跳、合闸回路工作状况,保证回路电器元件安全可靠运行,而且不会对系统正常运行造成影响。

Identifying hardware defects of DC operating circuit and discovering the hidden failures in relay protection device are important to ensure the correct and reliable operation of relay protection. In accordance with the operating principle, characteristics, and main defects of DC operating circuit, we proposed a new method of on-line monitoring and warning the DC operating circuit. The current of the trip circuit or closing circuit was on-line monitored to check whether DC operating circuit was disconnected or contacted well. Furthermore, time relay was added in the trip circuit and closing circuit to monitor its situation and avoid damaging circuit elements when there was breaker or pilot switch fault. On the basis of the line protective devices, we discussed the parameter setting and component selection method for monitoring devices. With 220 kV line protection as an example, the experiment was provided. The experimental results reveal that the proposed method can effectively realize integral monitoring of DC operating circuit in all conditions, and monitor the sit- uation of the trip circuit or closing circuit to ensure the safe and reliable operationof circuit elements without affecting the normal operation of DC operating circuit.