特高压交流系统过电压若干问题研究

发布时间：2018-01-06 13:40

本文关键词：特高压交流系统过电压若干问题研究　出处：《浙江大学》2014年硕士论文　论文类型：学位论文

【摘要】：从2009年第一条特高压单回交流输电线路成功投入运行至今以来,我国在特高压交流输电方面的运行经验越来越丰富。但是,特高压交流系统仍存在部分过电压的相关问题,尤其是针对远距离的特高压交流输电线路。本文主要对特高压交流系统单相接地故障过电压和特快速暂态过电压的相关问题开展研究。对于特高压交流长距离输电线路,单相接地故障过电压不容忽视。本文首先基于系统电源阻抗特性对该过电压的影响规律,提出了综合考虑该过电压的各影响因素后求取该过电压最大值的方法。在此基础之上,对特高压交流长距离输电线路的单相接地故障过电压的限制方法进行了探讨,结果表明采用MOA和高抗联合限制该过电压的措施是一种技术上可行、经济上占优的方法。其次,应用该限制过电压的方法,在保证整条线路沿线过电压不超过限制水平的前提下,对分3-5段的长距离输电线路合理的分段方式进行了研究。结果表明,对于分3-5段的线路,整条线路总长度分别不超过1300km、1400km和1600km时,过电压不会超过限制水平,且单段线路的最大长度分别可达500km、400km和400km。陡波前、高幅值的VFTO会对特高压GIS系统中GIS设备和变压器构成威胁。本文首先通过试验和仿真就架设于GIS出线套管与主变出线套管之间的架空线对入侵特高压变压器的VFTO波前陡度的限制效果进行了研究,探究了该段架空线长度与入侵主变的VFTO波前陡度之间的定量关系。结果表明,10-25m长的架空线能够很好的保护主变纵绝缘：当架空线长度在10m左右时,架空线能够非常明显的削弱到达主变端口的VFTO波前陡度；当架空线长度达到25m时,对于一般的特高压GIS变电站以及发电厂,到达变压器的VFTO波前陡度不会超出限制水平。此外,对比了特高压GIS变电站与特高压发电厂中VFTO特性的差异,可为工程实践提供借鉴。
[Abstract]:Since the first UHV single circuit AC transmission line was successfully put into operation in 2009, our country has more and more experience in UHV AC transmission. Some overvoltage problems still exist in UHV AC system. Especially for long-distance UHV AC transmission lines, this paper mainly studies the overvoltage of single-phase grounding fault and the ultra-fast transient overvoltage of UHV AC system. For UHV AC long distance transmission lines, the over-voltage of single-phase grounding fault can not be ignored. Firstly, based on the influence of the system power impedance characteristics on the over-voltage. A method for finding the maximum value of the overvoltage is proposed after considering all the influencing factors of the overvoltage. The method of limiting the over-voltage of single-phase grounding fault in UHV AC long distance transmission line is discussed. The results show that the method of combining MOA with high resistance to limit the over-voltage is technically feasible. Secondly, the method of limiting overvoltage is applied to ensure that the overvoltage along the whole line does not exceed the limit level. The reasonable segmental mode of long distance transmission lines with 3-5 segments is studied. The results show that the total length of the whole transmission line is not more than 1300 km for the line with 3-5 segment. At 1400km and 1600km, the overvoltage will not exceed the limit level, and the maximum length of the single section of the line can be up to 500km2 400km and 400km, respectively. Steep front. High amplitude VFTO will pose a threat to GIS equipment and transformer in UHV GIS system. In this paper, the overhead line between GIS outlet bushing and main transformer output bushing is first put up by test and simulation. The effect of limiting VFTO wavefront steepness of UHV transformer is studied. The quantitative relationship between the length of the overhead line and the VFTO wavefront steepness of the main intrusion transformer is investigated. The overhead wire with 10-25m length can protect the longitudinal insulation of the main transformer well: when the length of the overhead line is about 10m, the overhead wire can obviously weaken the VFTO wavefront steepness to the main transformer port; For general UHV GIS substations and power plants, when the length of overhead line reaches 25m, the front gradient of VFTO to the transformer will not exceed the limit level. The differences of VFTO characteristics between UHV GIS substations and UHV power plants are compared, which can be used for reference in engineering practice.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM862

【参考文献】