海上风电机组利用高桩承台基础作为自然接地体的仿真研究

Simulation Study on Using High-Rise Pile Cap Foundation as Natural Grounding Electrode of Offshore Wind Turbines

近海海底一般地形复杂,为了抗台风和抗海底冲刷的需要,海上风力发电机组的基础会使用高桩承台基础结构。高桩承台结构在高水位时,顶部水泥平台部分浸没水中,会影响入地电流流散,有必要对利用高桩承台基础作为自然接地体的可行性进行研究。建立了以高桩承台基础作为海上风电机组的自然接地体的仿真模型。利用将导体分段,求解各微段导体的格林函数,再叠加的方法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,得出接地电阻与水位变化的关系曲线。计算结果表明,海上风电机组利用高桩承台结构作为自然接地体能够满足实际工程的需要,为实际海上风电机组的接地设计提供参考。

Because of the special environment of the sea, in order to resist typhoon and seabed erosion, it is necessary to use the high-rise pile cap foundation. The top platform will influence the grounding resistance when the level of seawater is high, so, it is necessary to study the feasibility of using this foundation as the natural grounding electrode. A simulation model that use high-rise pile cap foundation as natural grounding device is established. 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 sea water level is established. The results show that using the high-rise pile cap foundation as a natural grounding electrode is satisfactory for the safe grounding of offshore wind turbines, and it can be a reference to the grounding design of offshore wind turbines.