Abstract High Voltage Direct Current (HVDC) system operating under monopole-ground-return mode will cause the earth potential to rise within a range, which will affect the normal operation of nearby AC system. The HVDC system can be divided into “above-ground part” and “underground part” by the ground interface. This article proposes an exact equivalent model of the “underground part” that can be modeled together with the “above-ground part” during analyze the operation of the whole HVDC system, namely the distributed-parameter resistance earth model. Firstly, the equivalent method of the ground current loop during monopole-ground-return operation is studied, and its equivalent model is established. Secondly, the ground which the current passes is divided into three layers in the horizontal direction. The exact distributed-parameter resistance earth model is established and the calculation method of the distributed resistance are obtained. Finally, taken an actual case as research object, by comparing the earth potential calculated by the model and simulation results in Current Distribution, Electromagnetic fields, Grounding and Soil structure analysis (CDEGS), the accuracy of the model and the solution of its parameter are verified.

中文翻译：

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单极接地回直流高压直流分布参数电阻接地模型及电位分布研究

摘要 高压直流（HVDC）系统运行在单极-接地-返回模式下，会引起地电位在一定范围内升高，从而影响附近交流系统的正常运行。高压直流输电系统按地面接口可分为“地上部分”和“地下部分”。本文提出了在分析整个高压直流系统运行时可以与“地上部分”一起建模的“地下部分”的精确等效模型，即分布参数电阻接地模型。首先，研究了单极接地回路运行时接地电流回路的等效方法，并建立了等效模型。其次，电流通过的地面在水平方向上分为三层。建立了精确的分布参数电阻接地模型，得到了分布电阻的计算方法。最后，以一个实际案例为研究对象，通过比较模型计算的地电位与电流分布、电磁场、接地和土壤结构分析（CDEGS）中的模拟结果，模型的精度及其参数的解为验证。