一种线路纵差保护通道监测的新方法

介绍了一种线路纵联差动保护的通道监测新方法，包括如下步骤:线路两侧差动保护装置按设计的报文帧格式相互通信;计算并存储每一帧报文传送的通道延时;根据判据不等式判断通道延时的稳定性，若通道延时满足判据不等式则判为通道运行不稳定，闭锁保护功能。该方法通过实时监测通道延时跃变，较好地避开了路由转换中的风险，充分考虑到在通道路由切换的过程中保证差动保护的可靠性，消除保护装置误动作的事故。判据针对的是通道延时跃变时间而非通道延时本身，对不同延时的通道具有自适应性，兼顾了高可靠性和高灵敏性。

A New Channel Monitoring Method for Fiber-optic Line Differential Protection

A new channel monitoring method for the fiber-optic longitudinal differential protection is put forward which consists of the following steps,viz.correspondence between the differential protections at the two ends of the line in the designed message frame format;the communication channel delay in calculating and storing each message frame;judgment of the stability of channel delay according to the criterion inequality.If the communication channel delay satisfies the criterion inequality,it is concluded that the channel is unstable and the closedown protection.The method bypasses the risk in routing switching by monitoring the channel delay jump,and by taking into full consideration the guarantee of the reliability of differential protection in the process of communication channel routing switching,the maloperation accident of protections is eliminated.The criterion focuses on the time of channel delay jump rather than the channel delay itself and is adaptable to channels with diverse delays.The application results verify that the proposed method has high sensitivity and reliability.