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

双绞线传输线是由几条线路组成的传输线，是计算机网络系统中广泛使用的数据通信信号线。采用矩量法（MoM）这一电磁场数值计算方法，对双绞线单相电力线路的浪涌特性进行了研究。通常情况下，对频谱的计算时间较大，但该方法的优点是易于对双绞线等复杂结构进行建模。为分析风力发电系统中电力电缆和控制电缆系统中产生的浪涌，建立了模型。在实际应用中，考察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。对于降低过电压的有效接地电极的浪涌特性，通过与实验结果和仿真结果的比较，表明了MoM和FDTD两种分析方法的特点，可以应用于电极设计。采用矩量法和时域有限差分法建立了用于分析变压器浪涌特性的铁芯仿真模型。考虑等效岩心模型，从蒙皮深度到块状模型和层状模型，得到岩心渗透率、电导率与层数的关系。为了验证仿真模型，进行了冷轧硅片的实验，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