酒湖特高压直流输电系统故障对送端风机的影响

发布时间：2018-05-20 23:16

本文选题：特高压直流 + 风电场　；参考：《兰州理工大学》2017年硕士论文

【摘要】：随着社会经济的快速发展,我国对能源需求日益增长。这就要求我国在资源分布极度不均的情况下,进行能源的优化配置。近些年来为解决我国能源负荷供需矛盾,将在风能资源集中的内陆地区建设数个千万千瓦级的大规模风电基地。由于大多数风电地区都表现出低负荷、弱电网的典型特征,因此风电经特高压直流外送势在必行。酒泉-湖南±800k V特高压直流输电就是规划2014年开工建设的一条,计划把甘肃酒泉地区的风电、光伏通过特高压直流送往湖南,实现大规模清洁能源的利用。但酒湖直流工程初期投运仍然存在许多不稳定因素。酒湖直流系统换相失败引起交流电网过电压的情况下,由于风电场相对于常规火电厂抗干扰能力较差,所以多数风力发电机组都面临着被破坏的风险,严重情况下可能造成大规模风力发电机组大面积脱网,直接威胁系统安全。针对以上问题,研究酒湖特高压直流换相失败对酒泉风电的影响将成为热点。目前,针对酒湖特高压直流换相失败的研究工作主要集中在对其的建模仿真,抑制由于换相失败而产生的暂态过电压策略等。本文依据酒湖特高压直流实际工程数据,基于PSCAD/EMTDC仿真平台搭建了酒湖特高压直流简化模型。首先简要阐述了如何搭建发电机、变压器、大容量双馈风机等基本模型,并详细介绍了各个模型在搭建过程中需要注意的问题和相关参数的设置;然后在搭建好的模型基础上进行了仿真试验,验证了各个模型的正确性,通过各个模型的相互联系和作用深入了解换相失败故障对交流系统过电压的影响,并探讨了酒湖特高压直流系统发生换相失败对酒泉地区风电场母线过电压的影响。结合仿真结果,从原理上说明了影响风电场母线过电压的因素。最后参照国外对风电场并网母线高电压穿越的基本规范,提出了酒泉地区风电场高压穿越标准的初步性建议。最终,本文结合酒泉风电高电压穿越规范标准,提出通过在酒泉风电场并网母线安装静止无功补偿器SVC来抑制暂态过电压的策略,并通过仿真实验验证了该方案能够在一定程度上避免过电压的发生。
[Abstract]:With the rapid development of social economy, the energy demand of our country is increasing day by day. This requires our country in the extremely uneven distribution of resources, the optimal allocation of energy. In recent years, in order to solve the contradiction between supply and demand of energy load in China, tens of millions of kilowatts large scale wind power bases will be built in inland areas where wind energy resources are concentrated. Due to the typical characteristics of low load and weak power network in most wind power areas, it is imperative for wind power to be sent out through UHV DC. Jiuquan-Hunan 卤800kV UHV HVDC transmission is one of the planned construction projects in 2014. It is planned to send wind power and photovoltaic energy from Jiuquan area of Gansu Province to Hunan through UHV DC to realize large-scale utilization of clean energy. However, there are still many unstable factors in the initial commissioning of Jiuhu DC project. In the case of AC grid overvoltage caused by the commutation failure of Jiuhu DC system, most wind turbines are at risk of being destroyed because of the poor anti-interference ability of wind farms relative to conventional thermal power plants. In serious cases, large scale wind turbines may be removed from the grid in a large area, which directly threatens the safety of the system. In view of the above problems, the research on the effect of UHV DC commutation failure on Jiuquan wind power will become a hot spot. At present, the research on DC commutation failure of Jiuhu UHVDC is mainly focused on modeling and simulation to suppress the transient overvoltage strategy caused by the commutation failure and so on. Based on the actual engineering data of UHV DC in Liquor Lake, a simplified model of UHV DC in Liquor Lake is built based on PSCAD/EMTDC simulation platform. Firstly, the basic models of generators, transformers and large capacity doubly-fed fans are briefly described, and the problems needing attention and the setting of related parameters in the process of building each model are introduced in detail. Then the simulation experiment is carried out on the basis of the established model, which verifies the correctness of each model. Through the mutual connection and function of each model, the influence of commutation failure fault on the AC system overvoltage is deeply understood. The effect of commutation failure in Jiuhu UHV DC system on the overvoltage of wind farm busbar in Jiuquan area is also discussed. Based on the simulation results, the factors affecting the overvoltage of wind farm busbar are explained in principle. Finally, referring to the basic standards of high voltage traversing of wind farm connected to grid bus, the paper puts forward the preliminary suggestion of high voltage crossing standard of wind farm in Jiuquan area. Finally, combining with the high voltage traversing standard of Jiuquan wind power plant, this paper puts forward a strategy to suppress transient overvoltage by installing static Var compensator (SVC) on the grid bus of Jiuquan wind farm. The simulation results show that the scheme can avoid overvoltage to some extent.
【学位授予单位】：兰州理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM721.1;TM315

【参考文献】