基于地电位特征和Chan算法的轨道交通钢轨绝缘破损点定位方法

A Method for Locating Insulation Damage Points on Rail Transit Based on Ground Potential and Chan Algorithm

针对轨道交通钢轨扣件绝缘破损导致轨地过渡电阻降低、杂散电流激增进而腐蚀埋地金属结构的问题,提出了钢轨局部绝缘破损时的杂散电流动态分布建模方法。结合轨道交通牵引特性和地电场理论计算轨道交通运行区间内的地电位分布,根据地电位分布及电位梯度评估了钢轨扣件绝缘破损时杂散电流的干扰范围。基于到达时间差(TDOA)定位模型中的Chan算法对地电位时域信号进行两次加权最小二乘法估计,实现了对钢轨绝缘破损点的定位,并分析了算法在不同数量的地电位观测点下的误差和抗噪声能力。仿真验证了破损点定位算法的准确性。

A dynamic distribution modeling method for stray current is proposed to address the problem of insulation damage of rail transit fasteners leading to a decrease in rail to ground transition resistance and a surge in stray current that corrodes buried metal structures.Based on the traction characteristics of the rail transit and the theory of geoelectric field,the dynamic ground potential distribution within the rail transit operating range is calculated.The interference range of stray current during insulation damage of steel rail fasteners is evaluated based on the ground potential distribution and gradient.Based on the Chan algorithm in the TDOA positioning model,a two-step WLS estimation is performed on the time-domain signal of ground potential to locate the point of insulation damage on the steel rail.Finally,the average error and noise resistance of the algorithm under different numbers of ground potential measurement points are analyzed to verify the accuracy of the positioning algorithm.