温差条件下染污绝缘子受潮机理及污秽度在线监测方法研究

Pollution flashover threatens the stability of the power grids, and studying the wetting characteristics of insulators is of great significance for the pollution flashover mechanism and on-line monitoring of contaminated insulators. In the clear night with the windless or soft wind (wind speed is less than 0.5m/s), due to the radiation cooling, the temperature of insulators may be lower than that of the surrounding atmosphere, which leads to the rapid wetting of the contamination layers. The pollution flashovers occurring in the desert areas may be related to the wetting of insulators under temperature difference. It was generally believed that under temperature difference, the wetting of contamination layers was related to the condensation. However, according to the applicant's previous researches, it was found that even if the condensation condition was not met, the wetting degree of pollution layers would be aggravated and the wetting mechanism of insulators under temperature difference is not clear yet. This project plans to comprehensively study the influence of environmental parameters (temperature, humidity), insulator and its surface contamination on the leakage current and water absorption of the contamination layers under temperature difference, reveals the wetting mechanism of the pollution layers and proposes the online monitoring method of insulator contamination under temperature difference. The research results do not only have important theoretical significance in deepening the understanding of pollution flashover mechanism, but also provide a basis for the online monitoring of insulator pollution in arid regions.

污闪事故严重影响电力系统的安全稳定运行，研究染污绝缘子的受潮特性对理解污闪机理和实现污秽度在线监测有着重要意义。在晴朗、无风或软风（风速小于0.5 m/s）的夜间，由于辐射冷却，绝缘子温度可能低于周边大气环境温度，导致表面污层快速受潮。沙漠地区发生于晴朗凌晨的污闪事故可能和绝缘子温差受潮有关。目前国内外对绝缘子温差受潮特性研究涉及较少，一般认为其与自然环境中的凝露现象有关，然而申请人前期试验发现：即使没有达到凝露条件，污层受潮程度也会因温差的存在而加剧，染污绝缘子的温差受潮机制尚不清晰。本课题计划综合研究在温差条件下，环境参数（温、湿度）、绝缘子及其表面污秽属性等对泄漏电流、污层吸水量的影响，揭示染污绝缘子的温差受潮机理，提出温差受潮条件下的绝缘子污秽度在线监测方法。研究结果可以加深对污闪机理的理解，具有重要理论意义，并为内陆干旱地区的绝缘子污秽度在线监测提供依据。

污闪事故严重影响电力系统的安全稳定运行，研究染污绝缘子的受潮特性对理解污闪机理和实现污秽度在线监测有着重要意义。在晴朗、无风或软风（风速小于0.5m/s）的夜间，由于辐射冷却，绝缘子温度可能低于周边大气环境温度，导致表面污层快速受潮。沙漠地区发生于晴朗凌晨的污闪事故可能和绝缘子温差受潮有关。目前国内外对绝缘子温差受潮特性研究涉及较少，染污绝缘子的温差受潮机制尚不清晰。本课题综合研究在温差条件下，环境参数（温、湿度）、绝缘子及其表面污秽属性等对泄漏电流、污层吸水量的影响，揭示染污绝缘子的温差受潮机理，提出温差受潮条件下的绝缘子污秽度在线监测方法。研究结果可以加深对污闪机理的理解，具有重要理论意义，并为内陆干旱地区的绝缘子污秽度在线监测提供依据。