A Basic Study of New Design Method for Higher Lightning Protection Performance in Electrical Apparatus

由多条线路组成的双绞线传输线是计算机网络系统中广泛使用的数据通信信号线。采用数值电磁场计算方法--矩量法，研究了双绞线单相电力线的冲击特性。针对传统的频谱分析方法计算量大、易于对双绞线等复杂结构建模的缺点，利用矩量法对风力发电系统中电力电缆和控制电缆系统中产生的浪涌进行了分析。作为应用，研究了电缆接地方式对过电压的影响，明确了降低过电压的接地方式。在降低过电压的有效接地极的浪涌特性方面，通过与实验结果和仿真结果的比较，阐明了MoM和FDTD两种分析方法的特点，并将它们应用于电极设计。对用矩量法和FDTD法分析变压器浪涌特性的铁芯仿真模型进行了验证。考虑了等效铁心模型，考虑了铁心磁导率与铁心磁导率、铁心磁导率和磁芯磁导率之间的关系，给出了铁心磁导率与磁芯磁导率、磁芯磁导率和磁芯磁导率之间的关系。得到了从皮肤深度到块体模型和层合模型的电导率和层数。为了验证仿真模型，对冷轧硅钢片进行了实验，仿真结果与实验结果吻合较好。

Twisted pair transmission line composed of several lines is used widely as data communication signal lines in computer network system. We used the Method of Moments (MoM), which is a numerical electromagnetic field computation method, to study the surge characteristics of twisted pair single phase electric power line. In generally large computing time is required for the frequency spectrum, but the method has an advantage that it is easy to model complex structures such as twisted pair.The cable model was studied to analyze the surge which arises in power cable and control cable system of wind power generation system by MoM. As the application, the overvoltages depending on the grounding method of the cable was examined, and grounding method which reduced the overvoltage was clarified.In respect of the surge characteristic of the effective grounding electrodes for the reduction in the overvoltage, it was shown that it clarified features of each analysis method, MoM and FDTD, in comparison with experimental results and simulation ones,and that we can apply them to the electrode design.The simulation model of iron core used to analyze surge characteristic of the transformer using moment method and FDTD method was examined.Equivalent core model is considered, and the relationship between the core permeability, conductivity and the number of lamination is obtained from skin depth to the massive model and the laminated one. In order to verify the simulation model, the experiment using cold rolling silicon sheet was carried out, and the simulation result and experimental result shows good accordance