在高压直流输电系统中，换流站中性母线区域作为两极的公共部分，涉及众多直流保护功能而且逻辑关系复杂，这些保护导致的动作后果，又往往会影响到另一极的运行，接地极断线保护动作就是其中一个典型案例。介绍了高压直流输电系统接地极断线保护的目的、原理和保护动作等相关内容，针对华新换流站阀厅中性线直流分压器故障引起接地极断线保护误动，可能导致双极系统强迫停运的隐患进行分析，并且提出了相应的解决方法。

In the HVDC system, the converter neutral busbar zone as the poles of the public part, involves numerous DC protection function with complex logic, these protection lead to the consequences of the action often affects another pole, and earthing pole broken line protection is one of the typical case. Through the introduction of the HVDC system earthing pole broken line protection purposes, principles and protection action, focusing on analysis of the neutral DC voltage divider failure led to the earthing pole broken line protection misoperation may cause bipolar system forced blocking, and putting forward the corresponding solutions of this hidden danger.