1000kV特高压输电线路分布电容对继电保护影响的研究

发布时间：2018-02-04 05:27

本文关键词： 特高压分布电容电流电流差动保护时域补偿自适应　出处：《广西大学》2014年硕士论文　论文类型：学位论文

【摘要】：1000kV特高压交流输电线路在实现电力资源的优化配置,推动电力科技自主创新和新能源的高效率开发,促进居住环境的可持续发展等方面具有重要的作用。然而特高压交流输电线路上巨大的分布电容电流对分相电流纵联差动保护产生严重的影响,使其灵敏性和安全性不能满足特高压线路保护的要求。因此,对这一问题进行深入和详细的研究,并提出解决该问题的方法具有一定实践意义。首先,本文详细分析了特高压交流输电线路的物理特征和数学模型、线路保护的配置及原则、分布电容电流的数学计算公式,并建立了1000kV特高压交流输电线路的PSCAD/EMTDC模型,仿真研究了不同电压等级的分布电容电流大小。其次,理论分析了特高压输电线路巨大的分布电容电流对全电流纵联差动保护、故障分量电流纵联差动保护和零序电流差动保护的影响,同时建立了三种保护的EMTDC仿真模型,分别仿真研究了线路保护在不同故障地点、不同过渡电阻、不同电源相角差以及不同合闸等情况下受分布电容电流影响情况。最后,针对分布电容电流对电流差动保护产生严重影响的问题,分析对比了高压并联电抗器补偿法、相量补偿法和时域补偿法的优缺点,并对其存在的补偿误差大的问题,本文提出了自适应时域补偿方法并进行了理论分析。通过EMTDC仿真研究表明,该方法能够很好地提高补偿精度和电流差动保护的灵敏度。
[Abstract]:1000kV UHV AC transmission lines are realizing the optimal allocation of power resources and promoting the independent innovation of power science and technology and the high efficiency development of new energy sources. Promoting the sustainable development of living environment plays an important role. However, the huge distributed capacitance current on UHV AC transmission lines has a serious impact on the differential protection of phase separation current. So that the sensitivity and safety can not meet the requirements of UHV line protection. Therefore, it is of certain practical significance to study this problem in depth and in detail, and to put forward the method to solve the problem. In this paper, the physical characteristics and mathematical model of UHV AC transmission line, the configuration and principle of line protection, and the mathematical calculation formula of distributed capacitance current are analyzed in detail. The PSCAD/EMTDC model of 1000kV UHV AC transmission line is established and the distributed capacitance current of different voltage levels is simulated. Secondly. The influence of the huge distributed capacitance current on the full-current longitudinal differential protection, the fault component current longitudinal differential protection and the zero-sequence current differential protection is theoretically analyzed. At the same time, the EMTDC simulation models of three kinds of protection are established, and the line protection in different fault locations and different transition resistance are simulated and studied respectively. Different power source phase angle difference and different switching conditions are affected by the distributed capacitance current. Finally, the distributed capacitance current has a serious impact on the current differential protection. The advantages and disadvantages of high voltage parallel reactor compensation method, phasor compensation method and time domain compensation method are analyzed and compared. In this paper, an adaptive time-domain compensation method is proposed and its theoretical analysis is carried out. The EMTDC simulation results show that the proposed method can improve the compensation accuracy and the sensitivity of the current differential protection.
【学位授予单位】：广西大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM773

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