中文摘要：

配电网高阻接地故障发生概率较大，对于小电阻接地系统，现场普遍采用的固定整定值零序过电流保护方法容易拒动。分析单相接地故障电气量特征发现，无论区外故障还是区内故障，保护安装处零序电流幅值与零序电压幅值成正比，且均随故障点接地电阻增大而减小。据此提出零序电压比率制动接地故障保护新原理，其核心是根据零序电压大小产生成比例的电流制动量，自适应调整零序过电流保护定值。该方法兼顾了低阻接地故障和金属性接地故障时的保护灵敏度与高阻接地故障时的保护可靠性，可将系统耐高阻能力提高到1000Ω，仿真验证了算法的可行性。

英文摘要：

High resistance grounding faults occur more often than not in the distribution network . For the low resistance grounding system , the zero‐sequence current protection with unchanged setting , which is widely used in the field , will refuse to operate . Based on an analysis of electric characteristic during a single‐phase grounding fault , it is revealed that , no matter whether the fault is internal or external , the magnitude of zero‐sequence current is always proportional to the magnitude of zero‐sequence voltage at the protection installed point on the line . And both magnitudes will be reduced with an increase in grounding resistance . According to this feature , a new principle of grounding fault protection based on zero ‐sequence voltage ratio restraint is proposed , whose core is that a self‐adaptive setting is constituted by producing a proportional current quantity according to the zero‐sequence voltage magnitude . Both the protection sensitivity for low resistance grounding faults or metallic grounding faults and the protection reliability for high resistance faults can receive adequate attention . The system is resistant to high resistance capacity which is improved to 1 000 Ω . Finally , simulation is performed to prove the validity of the algorithm .