风电接入对区域电网的电压稳定性研究

发布时间：2018-08-17 18:38

【摘要】：随着社会科技的发展,新型发电技术越来越成熟,其中风力发电的发展速度尤为明显。风电还具有很高的商业价值和环保价值,其前景不可限量,但是,风力发电也有他的不足之处,风资源的随机性和波动性都会对其可控性造成影响。相比于传统发电方式,风力发电还有很大的进步空间。风电并网会造成区域电网电压失稳等不良影响,这是目前热门的研究方向。本文的研究对象是某个实际电网A,当电网A中接入风电场时研究其电压稳定性的变化,分别对系统的静态电压与暂态电压的稳定性做出研究,通过在PSD-BPA程序中建立电网A的模型来研究风电场的接入对区域电网电压稳定性的影响,具体工作如下所示:(1)以容量为2MW的双馈型风力发电机为研究对象,构建了风力发电系统整体数学模型,包括:风轮模型,双馈型风力发电机模型,变流器模型,以及控制系统模型。(2)分析了电力系统电压失稳的静态机理和动态机理,包括电压失稳的判断依据。明确负荷裕度作为静态电压稳定性的判据;在分析暂态电压稳定性时考虑了风速波动和线路故障对其影响。(3)构建某电网A的系统模型,对其静态电压稳定性进行研究。计算风电场不同连接方式下变电站节点电压的U-Q灵敏度;分析风电场不同连接方式对变电站电压产生的影响,对电网A中安装固定无功补偿设备和提高风电机组机端电压两种运行方式进行比较。(4)针对电网A的暂态电压稳定性,分析了风力发电场风力变化和电网短路故障两种扰动下电网的暂态电压稳定性。并分析了动态无功补偿装置SVG安装前后电网电压暂态稳定性的差异。在并网出现三相短路故障时,安装SVG之后的电压跌落比之前的下降比例减少了10.06%,得出了在电网遭受短路故障时安装动态无功补偿装置SVG会提高电网的暂态稳定性。
[Abstract]:With the development of social science and technology, new generation technology is becoming more and more mature, especially the speed of wind power generation. Wind power also has high commercial value and environmental protection value, and its prospects are unlimited. However, wind power generation also has its shortcomings, the randomness and volatility of wind resources will have an impact on its controllability. Compared with the traditional power generation, wind power generation still has a lot of room for improvement. Wind power grid connection will cause voltage instability and other adverse effects, which is a hot research direction. The research object of this paper is a real power grid A, when the power grid A is connected to the wind farm, the change of voltage stability is studied, and the static voltage and transient voltage stability of the system are studied respectively. By establishing the model of power grid A in PSD-BPA program, the influence of wind farm access on the voltage stability of regional power network is studied. The specific work is as follows: (1) the double-fed wind turbine with capacity of 2MW is taken as the research object. The whole mathematical model of wind power system is constructed, including wind turbine model, doubly-fed wind turbine model, converter model and control system model. (2) static and dynamic mechanism of power system voltage instability is analyzed. Including the basis for judging voltage instability. The load margin is defined as the criterion of static voltage stability, and the influence of wind speed fluctuation and line fault on transient voltage stability is considered. (3) A system model is constructed and its static voltage stability is studied. The U-Q sensitivity of substation node voltage under different connection modes of wind farm is calculated, and the influence of different connection mode of wind farm on substation voltage is analyzed. This paper compares the two operation modes of installing fixed reactive power compensation equipment in power grid A and increasing the terminal voltage of wind turbine. (4) aiming at the transient voltage stability of power grid A, The transient voltage stability of the wind farm under the disturbance of wind power change and short circuit fault is analyzed. The difference of voltage transient stability before and after SVG installation of dynamic reactive power compensator is analyzed. When there is a three-phase short circuit fault in power grid, the voltage drop after installing SVG is 10.06 less than that before. It is concluded that the installation of dynamic reactive power compensator SVG will improve the transient stability of power network when the power network suffers short circuit fault.
【学位授予单位】：华北水利水电大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM614

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