Error in propagation velocity due to staircase approximation of an inclined thin wire in FDTD surge simulation
Error in propagation velocity due to staircase approximation of an inclined thin wire in FDTD surge simulation
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DOI：
10.1109/tpwrd.2004.835396
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发表时间：
2004-10-01
影响因子：
4.4
通讯作者：
Takahashi, Y
中科院分区：
文献类型：
--
作者：
Noda, T;Yonezawa, R;Takahashi, Y
本文研究了在时域有限差分(FDTD)涌浪模拟中，细导线阶梯近似引起的传播速度误差。FDTD方法通过将感兴趣的空间离散成立方体单元，直接求解麦克斯韦方程。因此，它适合于解决基于集中参数和分布参数电路理论的传统技术无法处理的非常快速的浪涌现象。然而，FDTD有一个限制，即导电对象的形状必须由具有强制零电场的单元的多个边的组合来建模。这表明，如果细导线不平行于用于离散化的任何坐标轴，则该细导线是浪涌模拟中最重要的组件之一，其结果是楼梯近似。阶梯近似给出较慢的传播速度，因为之字形路径比导线的实际长度长。为了进行精确的模拟，必须定量地澄清传播速度的误差。本文进行了大量的仿真，得到了速度-倾角特性，得出了传播速度的最大误差小于14%的结论。
This paper presents the result of a study on the error in propagation velocity introduced by the staircase approximation of a thin wire in the finite difference time domain (FDTD) surge simulation. The FDTD method directly solves Maxwell's equations by discretizing the space of interest into cubic cells. Thus, it is suitable for solving very-fast surge phenomena which cannot be dealt with by conventional techniques based on the lumped- and distributed-parameter circuit theories. However, FDTD has a limitation that the shape of a conductive object must be modeled by a combination of sides of cells with forced zero electric fields. This indicates that a thin wire, one of the most important components in the surge simulation, results in a staircase approximation, if the wire is not parallel to any of the coordinate axes used for the discretization. A staircase approximation gives a slower propagation velocity due to the zigzag path which is longer than the actual length of the wire. For precise simulations, the error in propagation velocity has to be clarified quantitatively. In this paper, extensive simulations are carried out to obtain the velocity versus inclination characteristic, and it is deduced that the maximum error in propagation velocity is less than 14%.