基于多重网格剖分技术的智能变电站接地网电磁响应数值模拟研究

Study on numerical simulation of electromagnetic response of intelligent substation grounding grid based on multi-grid partitioning technology

接地网在遭遇雷电击中或电路发生短路时能有效地分散所处区域的异常电流,对于变电站安全运行至关重要。传统的有限差分数值模拟算法在计算接地网电磁响应时,受限于接地网片状结构,网格剖分异常复杂,仿真效果较差。针对此问题,文章提出了一种基于多重网格剖分技术的频域有限差分算法,通过多重网格技术对接地网进行局部细化剖分,有效提升算法收敛速度并保证计算准确性。针对计算边界处理问题,提出了五点标定插值方法,解决了不同尺寸网格的电磁场连续性问题。经过算法比较和实际案例验证,基于多重网格剖分技术的频域有限差分算法,能够有效提升计算精度,增强识别效果,尤其是针对含有较复杂结构的异常体更有优势。

The grounding grid,composed of metal conductors in a mesh structure,effectively addresses overload current issues during lightning strikes and short-circuit faults.The integrity of its structure is crucial for the safe operation of substations.Traditional finite difference numerical simulation algorithms,when calculating the electromagnetic response of grounding grids,are limited by the planar structure of the grounding grid,leading to exceptionally complex grid division and thus limited calculation and identification capabilities.To address this issue,this paper proposes a frequency-domain finite difference algorithm based on multi-grid division technology.By applying multi-grid technology for localized refinement division of the grounding grid,the convergence speed and calculation accuracy of the algorithm are significantly improved.For the problem of boundary computation,a five-point calibration interpolation method is introduced,solving the continuity issue of electromagnetic fields across grids of different sizes.Through algorithm comparison and validation with actual cases,the frequency-domain finite difference algorithm based on multi-grid division technology effectively enhances calculation precision and identification capabilities,especially offering advantages for bodies with more complex structures.