基于电容层析成像的电缆绝缘缺陷检测仿真研究

Simulation Research of Cable Insulation Defect Detection Based on Electrical Capacitance Tomography

电力电缆绝缘性能优越,在轨道交通系统和电力系统中应用广泛,但是在外部绝缘劣化因素的长期作用下易发生绝缘故障,影响系统的供电稳定性。为了准确判断电缆绝缘状态,确保系统安全稳定运行,开展了基于电容层析成像技术的电力电缆绝缘缺陷检测的仿真研究。建立了电力电缆和八电极电容传感器的模型,以信号输出强度为导向优化了电容传感器的几何结构,采用中值滤波算法优化了灵敏度场分布。利用Landweber图像重建算法结合优化后的电容传感器和灵敏度场,对气隙缺陷、水树缺陷、楔形划痕缺陷和复合缺陷4种典型的电缆绝缘缺陷进行了图像重建,实现了电力电缆绝缘缺陷的检测。

Power cables have excellent insulation performance and are widely used in rail transit systems and power systems, but they may suffer from insulation faults under the long-term action of external insulation degradation factors, which affect the stability of the system power supply. In order to accurately determine the status of cable insulation and ensure the safe and stable operation of the system, a simulation study is conducted on the detection of insulation defects in power cables based on electrical capacitance tomography. A model of power cable with eight-electrode capacitive sensor is constructed. The geometry of the capacitive sensor is optimized in terms of signal output strength, and the sensitivity field distribution is optimized using the median filtering algorithm. By integrating the optimized capacitive sensor and sensitivity field, employing Landweber image reconstruction algorithm, the reconstruction of images representing four typical cable insulation defects: air gap, water tree, wedge-shaped scratch, and composite defects, is facilitated, thus enabling the detection of power cable insulation defects.