直流GIL中金属微粒对绝缘子表面电荷积聚的作用机制研究

发布时间：2018-01-03 23:04

本文关键词：直流GIL中金属微粒对绝缘子表面电荷积聚的作用机制研究　出处：《华北电力大学(北京)》2016年硕士论文　论文类型：学位论文

【摘要】：气体绝缘金属封闭输电线路GIL (Gas Insulated Transmission)适用于传统直流架空线路受制约的区域,在未来全球能源互联网建设中具有广阔的应用前景。而对于直流GIL,金属微粒及表面电荷积聚是引起其绝缘强度劣化的主要因素,且当金属微粒与表面电荷共同作用时,将对直流绝缘体系形成巨大的威胁。本文针对直流GIL中导电微粒污染问题,研究其对绝缘子表面电荷积聚的影响：首先基于麦克斯韦方程组,对绝缘子表面电荷的积聚情况进行分析,并进-步纳入微粒污染以及气体侧空间离子的产生、复合、迁移、扩散等作用,利用多物理场仿真软件COMSOL建立绝缘子表面电荷积聚的微观模型,分析了直流电压下绝缘子模型表面电荷积聚的时间效应及电压特性,并深入探究微粒对表面电荷积聚效应的影响；另一方面,为验证仿真分析的正确性,建立考虑金属微粒影响的旋转式电荷测量实验平台,并对应仿真分析分别针对电荷积聚的时间效应和电压特性以及微粒尺寸和微粒附着位置对电荷积聚的影响几个方面进行实验研究,从实验的角度揭示表面电荷和金属微粒对直流GIL绝缘强度的劣化作用；进一步以实体建模方式建立直流GIL中包含微粒污染的绝缘子表面电荷积聚模型,分析柱式和盆式绝缘子表面电荷的分布规律,并针对金属微粒在GIL中“附着”与“悬浮”两种主要存在形式,深入探究附着微粒和悬浮微粒对柱式绝缘子表面电荷积聚的影响。简化模型的仿真分析和实验结果表明：考虑金属微粒影响的电荷仿真模型与实验值相吻合,验证了仿真模型的可靠性。进一步,实体建模中金属微粒对绝缘子表面电荷积聚的影响主要表现为：绝缘子表面电荷积聚与绝缘子表面场强的法向分量具有一致性；附着绝缘子表面的导电微粒能引起表面电荷积聚激增,其中附着在中间部位的微粒引起的电荷激增量更为显著,且微粒两端积聚电荷的电性相反,并与微粒尖端所对电极极性相反；悬浮微粒对表面电荷积聚的影响较小,当悬浮微粒距绝缘子表面垂直距离超过4倍微粒直径时,其对绝缘子表面电荷的影响可以忽略。本文研究结论有利于深化对直流GIL中沿面闪络故障和微粒引起气隙击穿的机理认识,并为直流GIL中绝缘子结构设计和金属微粒污染物的无害化措施提供一定的理论指导。
[Abstract]:Gas insulated transmission line GIL (Gas Insulated Transmission) is suitable for the traditional DC overhead line is restricted by the region, has broad application prospect in the future construction of the global energy Internet. For DC GIL, metal particles and surface charge accumulation is the main factors of the insulation strength deterioration, and when the interaction of metal the particle and surface charge, the DC insulation system formed a huge threat. Aiming at the pollution problem of conductive particles in DC GIL, to study its effect on insulator surface charge accumulation: firstly, based on the Maxwell equations, analysis of insulator surface charge accumulation, and further into the particulate and gas side space ion production of composite, migration, diffusion, microscopic model of insulator surface charge accumulation by using multi physics simulation software COMSOL, divided The effect of time under DC voltage of insulator surface charge accumulation model and voltage characteristic analysis, and explore the effect of particles on the surface charge accumulation effect; on the other hand, in order to verify the correctness of the analysis simulation, establishment of rotary charge measurement considering the metal particles impact experiment platform, and the corresponding simulation analysis of time effect for charge respectively. The accumulation and voltage characteristics as well as the particle size and particle attachment location effect on charge accumulation in several aspects of experimental research, revealing the surface charge and metal particles insulation deterioration effect strength of DC GIL from the experimental point of view; further insulator surface charge accumulation model containing particulate pollution in DC GIL based on solid modeling, analysis distribution of the column and the insulator surface charge, and the metal particles in GIL "attachment" and "suspended" two main To form, in-depth exploration of the adhesion of particles and suspended particles on the post insulator surface charge accumulation. The simplified simulation analysis and experimental results show that the model considering the charge simulation model and experimental effects of metal particles are consistent with the values, verify the reliability of the simulation model. Further, the influence of metal particles on insulator surface charge in solid modeling the main performance is: the accumulation of insulator surface charge accumulation and insulator surface field normal component is consistent; attachment of conductive particles on the surface of the insulator can cause surface charge accumulation in charge the adhesion of particles in the middle position caused by the surge in the amount is more significant, and electrically charged particles are accumulated instead, and particles the tip of the electrode of opposite polarity; suspended particles has little effect on the surface charge accumulation, when the suspended particles from the vertical surface of the insulator When the particle diameter is 4 times more than the distance, its impact on the insulator surface charge can be ignored. The conclusion of this study is conducive to deepening the mechanism of DC GIL along surface flashover fault and particles caused by air gap breakdown, provide certain theoretical guidance and harmless measures of pollutants for insulator and metal particles in DC GIL design sewage.

【学位授予单位】：华北电力大学(北京)
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TM216;TM75

【相似文献】