海上升压站利用基础作为自然接地体的仿真研究

Simulation Study on Using Foundation as Natural Grounding Electrode of Offshore Boost Station

海上升压站是大容量海上风电场的重要组成部分。为了抗台风和抗海底冲刷的需要,选址在近海海域和潮间带海域的海上升压站分别选取导管架和多桩作为基础类型。海水的深度,海水的电阻率,海床的电阻率以及潮间带地区的海床土壤结构,均会对入地电流的流散产生影响,有必要研究海上升压站利用基础作为自然接地体的可行性。建立了以导管架和多桩基础作为海上升压站的自然接地体的仿真模型,将导体分段,求解各微段导体的格林函数,再叠加求解出模型的接地电阻。在此基础上,利用指数函数模型拟合,得出接地电阻与各影响因素的关系。计算结果表明,海上升压站利用基础作为自然接地体能够满足实际工程的需要,为实际海上升压站的接地设计提供参考。

The offshore boost station is an important part of the large installed capacity offshore wind farm. In order to resist typhoon and seabed scouring, the boost station which located at coastal waters and intertidal zone usually use jacket or multi-pile foundation. The depth of sea water, the resistivity of sea water and resistivity of seabed and the soil structure of the seabed of an intertidal area will influence the grounding resistance. Therefore, it is necessary to study the feasibility of using the foundation as the natural grounding electrode of the offshore boost station. This paper made a simulation model that use jacket and multi-pile foundation as natural grounding device. As for simulation calculation, every conduct in this model is divided into several segments, and the Green's function of each segment is solved with complex image method. Finally, the grounding resistance can be obtained on the basis of the principle of superposition. And based on the result of simulation, the curve of the relationship between grounding resistance and all kinds of influencing factors are established. The results show that using the jacket and multi-pile foundation as a natural grounding electrode is satisfactory for the safe grounding of offshore boost station, and it can be a reference to the grounding design of offshore boost station.