矿用橡套屏蔽电缆绝缘不平衡对杂散电流分布的影响

在分析煤矿交流杂散电流产生机理的基础上,以矿用橡套屏蔽电缆为研究对象,建立了交流杂散电流分布参数模型,并通过理论计算与Matlab仿真分析以及RTDS实时仿真验证,研究了交流杂散电流沿着电缆长度方向的分布规律,总结了屏蔽电缆相间绝缘参数不平衡对交流杂散电流的影响。结果表明:沿着屏蔽电缆长度方向,流经屏蔽层、金属网的交流杂散电流有效值都先减小再增大,且在线路中点处均达到最小值;当电缆的相间绝缘电阻或分布电容不平衡度增大时,流经屏蔽层与金属网的交流杂散电流有效值均整体增大,不平衡系数K从1.25变为3,其增幅达到了10倍左右。

Influence of the unbalanced insulation of the mining rubber-sheathed shielded cable on stray current distribution

Taking the mining rubber-sheathed shielded cable as an example，the distributed parameter model for AC stray current was put forward according to analysis of the mechanism of AC stray current.Moreover，this paper presented the distribution law of AC stray current along the length direction of the cable，and discussed the influence of the unbalanced insulation of the cable on AC stray current through theoretical computing，simulating based on Matlab，and validating by RTDS.It has been shown by the simulation results that the AC stray current flows through the shielding layer of the cable and the metal mesh decreases first，then increases along the length direction，and can reach the minimum at the middle of the line.In addition，when K，the unbalance factor of the insulation resistance or distributed capacitance of the cable，increases from 1.25 to 3，the AC stray current flows through the shielding layer of the cable and the metal mesh can become 10 times larger than before at the same point of the line.