Flexible direct current transmission network area pilot protection method and device based on extended boundary

The invention relates to a flexible direct current system area pilot protection method and device based on an extended boundary. The method comprises the following steps: determining protection action time tDW; determining a protection measurement point in the tDW, and calculating a voltage fault component; according to the voltage fault component of the protection measurement point, obtaining judgment results of a starting criterion, a direction identification criterion, a pole selection criterion and a lightning stroke locking criterion in the tDW; and acquiring information of adjacent measuring points according to the judgment result to form cooperation of area protection. According to the method, the requirement for the sampling rate is low, a large amount of data transmission is not needed, and the method still has high sensitivity and reliability under high-resistance faults and strong noise and when boundary characteristics are weakened. 本发明涉及一种基于扩展边界的柔性直流系统区域纵联保护方法及装置，包括以下步骤：确定保护动作时间tDW；确定tDW内保护测量点，计算