铜覆钢阻抗特性的理论推导及分析

铜覆钢接地材料广泛应用于接地工程中,研究铜覆钢的阻抗特性对接地网的设计和运行具有重要意义。为此,基于柱坐标系下的麦克斯韦方程组建立电场强度的微分方程,利用贝塞尔函数推导了铜覆钢的电场强度分布和单位长度轴向阻抗计算公式,通过comsol有限元法进行对比证明了理论公式适用于任意频率的工况,分析了铜覆钢电流密度的分布规律,比较了铜覆钢与铜、钢轴向阻抗的区别,并研究了铜覆钢镀层厚度对其轴向阻抗阻抗模、阻抗角、电阻分量及电抗分量的影响,为复合接地导体在接地工程中的应用提供参考。

Derivation and Study of Impedance Characteristics of Copper-clad Steel

Copper-clad steel grounding materials are widely used in grounding engineering. It is important to study the impedance characteristics of copper-clad steel for the design and operation of grounding grid. In this paper, the differential equation of electric field intensity was established based on Maxwell''s equations in cylindrical coordinate system. The electric field intensity distribution and the calculation formula of axial impedance per unit length of copper-clad steel were derived by using Bessel function. Comsol finite element method was used to prove that the theoretical formula is applicable to any frequency. This paper analyzed the distribution of current density of copper-clad steel, compared the axial impedance between copper-clad steel and copper and steel, and studied the influence of coating thickness of copper-clad steel on the impedance mode, impedance angle, resistance component and reactance component of its axial impedance, which provides reference for application of composite grounding conductor in grounding engineering.