覆藻硅橡胶材料表面闪络机理的研究

The surface of the composite insulation material usually covers a large number of microorganisms when the high voltage transmission lines pass through the humid area, and the biological contaminates threaten the stable operation of the power system seriously. Micro-algae contamination is a special natural contamination in a dynamic change, because cell membrane hydrophilic function destroys the surface of silicone rubber original hydrophobic property and hydrophobicity transfer property, thus the flashover process of the algae-fouled silicone rubber surface is different from the general case of the composite insulation flashover process, and this aspect of the study is still in the blank stage. This project is to analysis the coverage and accumulation rule of biological contaminates based on the dynamic biological contamination growth characteristics. Bio-film has two typical characteristics including extracellular polymers and biological electricity. Combined these typical characteristics, algae influence on the insulation properties of silicone rubber is to be studied at the same time. Based on the laboratory simulation of the fouling process in a changing environment, the hydrophobicity reduction mechanism of the silicone rubber is to be explored in the paper through the moisture absorption characteristic of biological membrane and the biological corrosion process of silicone rubber. Artificial pollution flashover test and computer simulation are conducted to cognitive the discharge process and characteristics of the algae-fouled silicon rubber, and the biological pollution discharge model of silicon rubber is to be established. As the discharge process is explained, the mechanism of flashover is improved and the state evaluation and the early warning scheme for the algae-fouled outdoor organic equipment are put forward.

高压输电线路经过湿润地区时，复合外绝缘材料表面通常覆盖大量微生物，威胁电力系统稳定运行。藻类等微生物污秽是一种时刻处于动态变化的特殊自然污秽，其亲水机能破坏了硅橡胶表面原本优异的憎水性和憎水迁移性，致使覆藻硅橡胶的污闪过程与一般意义上的复合绝缘材料污闪过程差异较大，而这一方面的研究暂时处于空白阶段。本项目旨在基于生物污秽的动态生长特性，分析其覆盖规律及积累规律，结合藻类污秽的胞外聚合物和生物电特性两个典型特征，评判其对硅橡胶外绝缘性能的影响；基于实验室平台模拟变化环境下的积污过程，从生物膜吸湿性和硅橡胶生物腐蚀作用研究覆藻硅橡胶憎水性能弱化机理；基于人工污秽闪络试验和计算机仿真计算，认识覆藻硅橡胶放电过程与放电特征，建立生物染污硅橡胶放电模型，解释放电过程，完善闪络机理，最后提出覆藻硅橡胶设备状态评价和闪络预警方案。

高压输电线路经过湿润地区时，复合外绝缘材料表面通常覆盖大量微生物，威胁电力系统稳定运行。藻类等微生物污秽是一种时刻处于动态变化的特殊自然污秽，其亲水机能破坏了硅橡胶表面原本优异的憎水性和憎水迁移性，致使覆藻硅橡胶的污闪过程与一般意义上的复合绝缘材料污闪过程差异较大。.本项目着眼于覆藻硅橡胶闪络机理的研究，通过调研藻类在复合绝缘材料表面的生长特性，搭建藻类模拟生长环境试验平台，分析藻类覆盖规律及积累规律；结合藻类污秽的胞外聚合物，从生物膜吸湿性和硅橡胶生物腐蚀作用研究覆藻硅橡胶憎水性能弱化机理，评判其对硅橡胶外绝缘性能的影响；同时基于人工污秽闪络试验，对覆藻硅橡胶放电过程过程进行深入研究，完善闪络机理，最后提出覆藻硅橡胶设备状态评价和闪络预警方案。.研究结果表明，绝缘子表面藻类的生长分布受到温度、光照、湿度、降水、电场、伞倾角等多重因素的综合影响；绝缘子表面藻类的生长程度随季节气候变化呈周期性变化。结合特征绿值和图像分割，提出了基于数字图像分析技术的藻类检测方法，表征绝缘子表面藻类的生长程度。.纯藻可使硅橡胶表面憎水性下降或丧失，降低程度主要与环境湿度有关。憎水性的降低主要由胞外分泌物在不同环境下的吸湿特征引起。含藻混合污秽染污硅橡胶的憎水性介于纯无机物与纯藻类污染物之间，不可溶灰分有助于覆藻硅橡胶表面呈现憎水性。.建立了藻类不均匀分布的闪络试验模型。藻条连续时，藻类的径向覆盖角度与闪络电压负相关；藻条断续时，藻条宽度是影响闪络电压的主要因素，藻条越宽闪络电压越低。根据藻细胞密度、藻类覆盖率和等值盐密对污闪电压的影响，提出了绝缘子表面藻类生长程度的分级方法。.本项目首次针对复合材料绝缘子生物染污问题开展研究，填补了国内外绝缘表面覆藻问题研究的空白环节，完善了覆藻憎水性弱化理论和闪络理论，可为我国预防覆藻闪络事故提供重要的理论依据和实践指导。