交联聚乙烯绝缘高压电力电缆绝缘系统是由绝缘层与半导电层组成，半导电材料是聚烯烃弹性体材料和高结构炭黑共混而成，作为电缆绝缘层电场存在的边界层。由于半导电层与绝缘层的物理性质高度相近，又是在生产工艺中共同挤出制成，界面不会产生气隙，使从线芯屏蔽层的高电位到外屏蔽层的低电位间绝缘中的电场都处于完美的交联聚乙烯绝缘中，可承受较高的运行电压和使用寿命，根据等电位面上曲率半径小处会有较高的电场强度的原理，半导电层面向绝缘的界面如有凸起物，就会引起电场强度的高度增加，危害绝缘，因此对于半导电材料和电缆绝缘系统制造，要求严格限制半导电层表面突起物的数量和尺寸。具体落实到质量控制体系上，就是要控制半导电屏蔽料挤带成型品表面凸起物的数量和尺寸。 

高压电缆半导电屏蔽料表面光洁度检测系统开发基于高分子材料低温挤出流延技术，和电子摄像光学检测技术（或称机器视觉技术）。系统配备高速视觉相机以及特殊的LED扫描光源，实时监测凸起尺寸信息，图像处理能力为1500 万像素/秒。可实现高速高分辨力测量，同时，摄像系统具有宽视场、高像素，可以在对试品测量同时，同步对标定区测量，实现实时标定校准。

The structure of XLPE high voltage cable insulation is composed of an insulative layer and semiconductive layers. The semiconductiv material is a blend of polyolefin elastomer material and carbon black, which is used for the boundary layer of the electric field of the cable insulation layer. Since the physical properties of the semiconductive layer and the insulative layer are similar, they are also co-extruded in the production process, there is no air gap at the interface. The electric field in the insulation from the high potential of the core shielding layer to the low potential of the external shielding layer is perfect in XLPE insulation layer, which can withstand higher operating voltage and service life. According to the principle of higher electric field strength at the small curvature radius of the equipotential surface, the semi-conductive layer faces the insulation. If there are protrusions on the interface, it will cause the increase of the electric field strength to damage the insulation. Therefore for, the production of semi-conductive materials and cable insulation systems, it is required to limit the number and size of the protrusions on the surface of the semi-conductive layer strictly. The specific implementation of the quality control system is to control the number and size of the protrusions on the surface of the semiconductive material strip. 

The development of high-voltage cable semi - conductive shielding material surface finish detection system is based on low-temperature extrusion and casting technology of polymer materials, and electronic camera optical detection technology (or machine vision technology). The system is equipped with a high-speed vision camera and a special LED line-light source to detect size information of the protrusion in real time. The image processing capacity is 15 million pixels per second. It can achieve high-speed and high-resolution measurement. At the same time, the camera system has a wide field of view and high pixels. It can synchronous measure the calibration area while measuring the sample to calibrate real-time.