1000kV特高压空载线路合闸过电压的研究

发布时间：2018-03-16 03:25

本文选题：特高压　切入点：空载线路　出处：《广西大学》2014年硕士论文　论文类型：学位论文

【摘要】：特高压输电线路由于其参数、系统容量等特点使得其过电压比超高压线路更加严重。另外,其绝缘子等设备能够承受的过电压水平较低,易造成绝缘子的击穿或设备损坏,给电力系统造成巨大的经济损失。故开展特高压输电系统过电压的研究,采用有效措施,降低系统的过电压水平将是构建1000kV特高压电网的重要课题之一。本文以我国首条1000kV特高压交流输电线路为背景,从理论上分析了特高压输电线路在空载状态下合闸操作过电压的产生机理、影响合闸过电压倍数的各种因素及常用的限压措施。通过建立输电线路的等效模型,并采用改进欧拉法对合闸过电压进行数值计算,具体的求解计算过程借助VB6.0软件编程完成,得出过电压倍数。最后通过电磁暂态分析程序EMTP对合闸过电压进行仿真分析,以验证数值计算在思路、推导、求解等过程中的正确性与可行性。结果表明,在电源电压为峰值时进行合闸,过电压倍数高达2.5倍；在线路残压最大且极性相反时合闸,过电压倍数高达2.6倍；三相不同期合闸时,过电压倍数达到3倍以上。另外,在线路中部安装补偿度约为20%-40%的串联补偿电容器、在线路首末两端均安装补偿度约80%以上的并联电抗器、在断路器上安装两级并联电阻、沿线安装避雷器等措施均可使合闸过电压倍数降低,达到特高压输电线路对过电压倍数的要求。本文成果进一步丰富了特高压输电线路空载合闸过电压的基础理论和分析方法,对特高压输电技术领域的科学研究与工程设计具有重要意义。
[Abstract]:UHV transmission line because of its parameters, system capacity characteristics make the overvoltage is more serious than EHV line. In addition, the insulator and other equipment to withstand voltage level is low, easy to cause insulator breakdown or damage to the equipment, causing huge economic losses to the power system. Therefore, to carry out research on UHV transmission system. The voltage, the effective measures to reduce the voltage level of the system will be one of the important tasks of constructing the 1000kV UHV power grid.
Based on the background of China's first UHV AC transmission line 1000kV, from the theoretical analysis of the UHV transmission line in the state of no-load closing operation over-voltage generation mechanism, pressure measure of various factors affecting the switching overvoltage multiples and common limit. By establishing the equivalent model of transmission line, and by using the improved Euler numerical the calculation of the switching overvoltage, the specific calculation process using VB6.0 software programming, the overvoltage. The electromagnetic transient analysis program EMTP for switching overvoltage simulation analysis is carried out to verify the numerical calculation in ideas, derivation, feasibility and correctness of the solving process.
The results show that the closing of the supply voltage is peak, overvoltage multiples of up to 2.5 times; in the closing line and maximum residual voltage of opposite polarity, voltage ratio as high as 2.6 times; three phase switching overvoltage, reached more than 3 times. In addition, the central line is about compensation installation the series compensation capacitor 20%-40%, compensation degree and more than 80% shunt reactors are installed on the line ends, install two level shunt resistance on the circuit breaker, arrester installed along with other measures can make the switching overvoltage ratio decreased, reaching on UHV transmission line overvoltage requirements.
The results of this paper further enrich the basic theory and analysis method of over voltage of no load switching on UHV transmission lines, which is of great significance for the scientific research and engineering design of UHV transmission technology.

【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】：TM723

【参考文献】