交变磁场作用下的10 kV电缆微振动仿真研究

Research on Micro-vibration Simulation of 10 kV Cable under the Action of Alternating Magnetic Field

随着城市电力负荷的迅速增加,地下电缆逐渐成为电力输送的主要手段。在长期的电力运行中,电缆中间接头易出现间隙、裂痕等缺陷,为分析电缆中间接头在运行中微动磨损的振动来源及大小,通过对10 kV电缆线路中的三相线相间电磁力进行分析,建立10 kV电缆物理模型,仿真计算120 mm2电缆本导体及其附件的振动信号,并对比分析在不同载流量下的振动信号特征,为电缆中间接头在相间电动力振动下的可靠性研究提供理论基础。研究结果表明:在分量上电缆相间振动频率为工频的2倍,即为100 Hz;相间电动力应力集中在相间区域,该处振动最大位移为9.52×10^(-7)mm,最大加速度为0.267 mm/s^(2);铜线芯振动最大位移为1.63×10^(-6)mm,最大加速度为0.391 mm/s^(2)。

With the rapid increase of urban power load,the underground cable has gradually been becoming the main means of power transmission.During long time power operation,defects such as gaps and cracks in cables easily occurred.In order to analyze the vibration source and magnitude of fretting wear of cable intermediate joint during long-term power operation,the physical model of 10 kV cable was established by analyzing the electromagnetic force between three-phase lines in 10 kV cable line.The vibration signals of 120 mm2 cable conductor and its accessories were simulated and calculated,and the vibration signal characteristics under different current carrying capacity were compared and analyzed.It provided a theoretical basis for the reliability research of cable intermediate joints under interphase electrodynamic vibration.The results showed that the interphase vibration frequency of the cable was twice that of the power frequency,that was,100 Hz,and the interphase electrodynamic stress was concentrated in the interphase region,where the maximum displacement and acceleration were 9.52×10^(-7)mm and 0.267 mm/s^(2)respectively,and the maximum displacement and acceleration of the copper wire core were 1.63×10^(-6)mm and 0.391 mm/s^(2)respectively.