【作者】 伍飞飞；

【导师】 廖瑞金；

【作者基本信息】 重庆大学 ， 电气工程， 2014， 博士

【摘要】 特高压直流输电线路由于运行电压极性固定，电晕放电导致的空间电荷使得离子流场问题尤为严峻。开展电晕放电微观物理过程研究对于探求电晕放电的演化规律、指导输电线路离子流场计算具有重要理论价值。电晕放电微观过程中会产生大量激发态粒子、带电粒子、自由基等微观粒子，动理学规律极其复杂。由于缺乏有效的等离子体诊断手段，电晕放电的很多关键微观参数无法通过试验获得，国内外开展了大量电晕微观机理的数值研究，至今未取得突破性进展。可定量分析电晕放电微观物理过程的模型尚缺，对其影响因素的微观分析也未能深入。本文在流体动力学电晕放电模型的基础上，提出研究电晕放电微观物理过程的混合数值模型。采用棒-板电极最简模型对电晕放电脉冲电流进行了计算分析，研究电晕放电微观特征量在单次放电脉冲持续过程中的时空发展规律。建立了直流输电线路电晕放电宏观离子流场计算模型，讨论了输电线路结构对离子流场的影响，着重分析相对空气密度对离子流场的影响规律。本文的主要内容为：①首次提出了可量化研究电晕放电微观物理过程的混合数值模型。模型中利用流体动力学控制方程描述电晕放电的宏观物理规律；采用等离子体化学反应过程电晕放电微观过程中粒子的产生和消散过程；Boltzmann方程求解模块给流体动力学模型提供详细的电子输运参数和能量传递系数，同时给等离子体化学模型提供化学反应速率；通过试验得到的正负电晕放电单次脉冲波形和UI特性曲线证明了该模型的有效性。②计算分析了正负电晕的脉冲形成机制，在此基础上研究得到了负电晕放电的电子特性(平均电子能量、电子密度、电子的生成/消散速率等)和负电晕放电的重粒子特性(净空间电荷、等离子体化学反应速率、重粒子的成分及密度)在单次脉冲持续过程中的时空发展规律。③采用上流有限元法建立了直流输电线路电晕放电的宏观离子流场计算模型，利用单/双极试验导线的地面合成场强和离子流密度证明了模型的有效性，讨论了输电线路结构对离子流场的影响，着重分析了相对空气密度对离子流场的影响。对±800kV和±1100kV直流输电线路离子流场的计算结果表明，在跨越高海拔、高温度区域时，需要对输电线结构进行校验，确保其合成场强满足国家标准。更多还原

【Abstract】 The problem of ionized field caused by the space charge of corona becomes ratherserious for UHVDC transmission lines that due to the fixed voltage polarity. It’s of greattheoretical value to study the microscopic characteristics of corona discharge in order toexplore the and so on which results in the complexity of kinetics rule. A lot of key microparameters related to corona discharge can’t be obtained through experiments as lack ofeffective means for plasma diagnosis. There is no breakthrough on the research ofdevelopment law of corona discharge and to calculate the ionized field of UHVDCtransmission lines. Corona discharge generates a large number of excited particles, ions,free radicals corona mechanism, even a lot of efforts have been devoted. What’ worse,there is no model of corona discharge microscopic physical process which can be usedfor quantitative analysis.In this paper, an improved hybrid model based on fluid dynamics model isproposed to study the corona discharge microscopic physical process. A bar-to-platemodel is established for the calculation of corona pulse current, and for the research ofspace-time development law of corona discharge during the single pulse. A ionized fieldcalculation model is established to discuss the influence of transmission line structurethe relative air density on the ionized field. The main research results are as follows:①For the first time, a hybrid model of corona discharge is put forward for thequantifiable study of microscopic physical process. In this model, the fluid dynamicscontrol equation is used to describe the macro regularity of corona discharge; Theplasma chemical reaction process is used to analyze the generation and dissipationprocess of particles；The Boltzmann equation module provides electron transportparameters and the energy transfer coefficient for fluid dynamics control equation, andchemical reaction rate for plasma chemical reaction module. The validity is verifiedthrough the comparison of single pulse corona discharge waveform and U-Icharacteristic curve②The positive and negative corona pulse forming mechanism is analyzed. Baseon this mechanism, characteristics of electrons (such as electron mean energy, electron density, generation and dissipation rate of electrons) and characteristics of heavyparticle (such as net charge density, rate of plasma chemical processes, element andnumber density of heavy particle) during the single pulse is emphatically analyzed.③The ion flow field calculation model of corona discharge is established basedon the up stream FEM. The validity is verified through the experimental data of theground level total electric field and ion current density. The influence of transmissionline structure on ionized field is discussed, the influence of relative air density onionized field is emphatically analyzed. The calculation result of DC transmission lineshows that it’s essential to check transmission line structure via high altitude and hightemperature area in order to meet the national standard. The calculation result of±800kV and±1100kV DC transmission line on ionized field shows that it’s essential tocheck the transmission line structure when crossing high altitude and high temperaturearea in order to meet the national standard of total electric field strength.更多还原