通信与电力共用接地系统时域仿真模型及其对杆塔雷电响应特性的影响

Time Domain Simulation Model of Communication and Power Common Grounding System and Its Influence on Tower Lightning Response Characteristics

为降低工频接地电阻,通信基站地网需与电力杆塔接地组成共用接地系统。首先建立了共用接地系统的时域仿真模型,进而构建了杆塔-接地联合仿真模型,对接地系统共用后杆塔的雷电响应特性进行了分析。对于地下部分,基于矩量法数值仿真结果,通过矢量匹配法建立了能更精确描述共用接地系统宽频响应特性的时域等效电路模型,在频域求解中,采用一种基于有理逼近式的频率采样优化方法,可提升计算效率;对于地上部分,采用经典Hara多波阻抗杆塔模型。分别讨论了通信机房布置于杆塔根开内和旁侧2种情况,仿真结果表明,通信与电力接地系统共用前后塔顶及横担雷电暂态过电压最大值偏差较小,杆塔共享不会影响其雷电响应特性。

In order to reduce the power frequency grounding resistance, the communication base station grounding network should be bonded to the power tower grounding device to form a common grounding system. Firstly, the time domain simulation model of the common grounding system is established, and then the tower grounding union simulation model is constructed to analyze the lightning response characteristics of the tower shared with the grounding system. For the underground part, based on the numerical simulation results of the method of moments, the time domain equivalent circuit model is established by the vector fitting method, which can more accurately describe the broadband response characteristics of the common grounding system. In the frequency domain solution, a frequency sampling optimization method based on rational approximation is adopted, which can improve the calculation efficiency;for the ground part, the classical Hara multi-wave impedance tower model is adopted. The two situations of the communication room arranged root span or next to a tower are discussed respectively, the simulation results show that the maximum deviations of lightning transient overvoltages on the top and cross arm of the tower before and after communication and power grounding system sharing are small, and the tower sharing will not affect the lightning response characteristics of the tower.