电缆线路中操作过电压主导频率的确定方法  

Study on Dominant Frequency Determination of Switching Overvoltage in Cable Line

作　　者：李嘉明 陈曦[1] 郝一帆 邓军波[1] 张冠军[1] LI Jiaming;CHEN Xi;HAO Yifan;DENG Junbo;ZHANG Guanjun(State Key Laboratory of Electrical Insulation and Power Equipment(Xi'an Jiaotong University),Xi'an 710049,Shaanxi Province,China)

机构地区：[1]电力设备电气绝缘国家重点实验室(西安交通大学),陕西省西安市710049

出　　处：《电网技术》2020年第7期2785-2793,共9页Power System Technology

基　　金：国家电网公司科技项目(5226SX1600U9);国家自然科学基金项目(51577150)。

摘　　要：电缆模型参数的准确性对于电磁暂态仿真研究极为重要。为提升EMTP中电缆暂态操作过电压仿真结果与实际的一致性,提出了一种适用于EMTP电缆模型参数计算频率的确定方法。首先,基于分布参数理论,得到了单相纯电缆或架空线及混合线路中暂态过电压主导频率计算公式,并修改边界条件,考虑了电源阻抗对计算的影响。之后根据特征值变换与Fortescue变换,确定了纯电缆及电缆-架空混合线路的暂态过电压主导模回路。进一步,根据三相线路参数的频变公式可得主导模回路参数的频变公式,将其代入主导频率计算中即可得到主导频率与参数计算频率的变化关系。根据二者的一致性,可以确定参数计算频率的取值。对于电缆及其混合线路,采用该方法进行仿真研究,可得仿真结果的主导频率与参数计算频率表现出较高的一致性,验证了方法的准确性和可行性。Accuracy of cable parameters is very important for electromagnetic simulation research.To improve the consistency of the transient overvoltage in power cables simulated in EMTP with that in practice,the paper proposed a method for determination of the calculation frequency for cables.Firstly,equations for dominant frequency calculation of single-phase pure line and hybrid line were obtained based on distributed-parameter theory.By adjusting boundary conditions,the effect of source impedance could be considered.Then,according to eigenvalue transformation and Fortescue transformation,dominant modes of pure cable and hybrid cable-overhead line were determined.Further,by substituting the parameters of the dominant mode derived from the parameters in the phase domain,the relationship between the dominant frequency and the calculation frequency could be obtained.According to equivalence of these two kind of frequencies,the value of the calculation frequency could be determined.For cables and hybrid lines,simulation results revealed that the dominant frequency showed great agreement with the calculation frequency of parameters.Therefore,accuracy and feasibility of the proposed method were verified.

关 键 词：电缆 混合线路 暂态过电压 主导频率 参数计算频率 

分 类 号：TM86[电气工程—高电压与绝缘技术]