为研究树线故障时零序电压信号变化特征，搭建了树线故障实验平台，研究谐振接地系统不同残余电流下不同植被发生单相树线接地故障时的零序电压变化特性，总结了零序电压的变化阶段和规律，分析了残余电流和植被自身参数对零序电压变化的影响规律，并在此基础上建立了零序电压峰值预测模型。实验结果表明：树线故障的发展过程可由零序电压变化来表现，其变化一般存在缓增、速增、下降和回升4个阶段，变化趋势存在U形、J形、V形3种曲线；残余电流增大会导致零序电压变化幅度减小，不利于故障检测，其值应尽量补偿至0~1 A范围内；对于同种植被，零序电压峰值与含水率、直径呈正相关，峰值时间与二者呈负相关；不同种类植被结构差异也是影响零序电压峰值和峰值时间的关键。研究结果对于检测和预警树线故障引发山火事故具有重要意义。

In order to study the characteristics of zero sequence voltage signal change during tree line fault, an experimental platform for tree line fault is built to study the zero sequence voltage variation characteristics when single-phase tree line ground fault occurs in different vegetation under different residual currents in the resonant grounding system. The change stages and laws of the zero sequence voltage are summarized and the influence laws of the residual currents and vegetation's own parameters are analyzed on the change of the zero sequence voltage. Based on this, the prediction model for the peak value of the zero sequence voltage is built. The experimental results show that the development process of tree line fault can be expressed by the zero sequence voltage variation, which typically exhibit four stages: slow increase, rapid increase, decline and recovery. The trend of these changes follows three types of curves: U-shaped, J-shaped, and V-shaped. The increase of residual current will lead to a decrease in the amplitude of the zero sequence voltage change, which is not conducive to the detection of faults, and its value should be compensated to the range of 0~1 A as much as possible. For the same kind of vegetation, the peak zero-sequence voltage is positively correlated with the water content and diameter, and the peak time is negatively correlated with both of them. The structural difference of different kinds of vegetation is also the key to influence the peak zero-sequence voltage and peak time. The results of this study are of great significance for the detection and early warning of hill fires caused by tree line faults.