【作者】 王刚；

【导师】 王少荣；

【作者基本信息】 华中科技大学 ， 电力系统及其自动化， 2007， 硕士

【摘要】 近几年来,我国的电力系统正在向大电网、高电压和远距离输电方向发展,这对合理利用能源、提高经济效益具有十分重要的意义,但同时也给电力系统的安全、稳定运行带来了巨大的挑战。其中,电网发展带来的电压稳定问题越来越严重。基于GPS技术的广域测量系统(WAMS)能实时测量广域分布的电力系统状态和参数,为基于局部信息的电力系统稳定控制向全网协调稳定控制方向发展奠定了坚实的基础。本文在回顾和归纳现有的电压稳定分析理论的基础上,将WAMS引入到在线电压稳定分析领域,提出了一种基于WAMS的在线电压稳定分析方法。首先介绍了现有的静态电压稳定指标的研究成果,然后对几种电压稳定指标进行了仿真和分析,指出了它们的不足。然后提出了一种基于WAMS的系统实时状态信息进行电力系统动态等值的方法,利用最小二乘法辨识出ZIP负荷模型的比例参数,从而建立了负荷节点的系统动态等值模型,为电压稳定指标的推导做好准备。在上述系统动态等值和负荷参数辨识的基础上,本文利用负荷达到功率极限时以电压幅值为变量的功率方程的Δ=0的特征,提出了两种基于WAMS的电压稳定状态指标Lws和近似裕度指标Lwy,并对两者进行的仿真和比较,然后选取了状态指标Lws作为仿真的对象。将状态指标Lws和裕度指标在单负荷、区域负荷和全网负荷增长模式下进行的仿真。通过仿真和比较,说明了状态指标具有良好的线性度和计算快速性。最后仿真分析了负荷特性、OLTC和发电机无功输出限制对电压稳定指标的影响,证明了指标对系统电压稳定程度具有很好的描述特性。更多还原

【Abstract】 In recent years, our country’s power system has been developing into a large power grid, high voltage and remote transmission, which is not only extremely important to make use of energy more properly but also enhance the economy. But simultaneously, it also brings huge challenge to the power system’s security and stability operation. Among them, voltage stability problem is becoming more and more serious during the development of power system. Based on GPS Technology, Wide Area Measurement System (WAMS) is able to measure the power system’s Real-time states and parameters which are distributed in the wide area. Therefore, it establishes a solid basis owing to that they promote the power system’s stability control with the local information to the entire grid’s harmony control.After reviewing and summarizing the present theory of voltage stability analysis, this article has introduced WAMS into the area of online voltage stability analysis and proposed a method based on WAMS.Firstly, I have introduced the existing static voltage stable index theory, then carried out the simulation and analysis to several voltage stability indices and pointed out their disadvantages.Afterward, based on WAMS’real-time state information, I’ve proposed a new method to the power system’s dynamic equivalence and identify ZIP load model’s proportion parameter using Least Square Method, through which we have prepared for the voltage Stability index’s inferential reasoning.On the basis of the power system’s dynamic equivalence and load parameters identification, the article utilizes the power equation’s characteristic(Δ=0) , which takes voltage amplitude as variable, when load power reached the limits of power, to promote the voltage stability state index Lws and the approximate margin index Lwy based on WAMS. Through simulation and analysis of the two indices, I selected Lws to the simulated object. Then Lws and the voltage stability margin index were simulated in a single load, region load and the entire grid growth models. Through the simulation and comparison, showed Lws has the good linearity and the computation rapidity.Finally, the article has analyzed load characteristic, OLTC and generator reactive power limited to the voltage Stability state index’s influence, which proved that index had a good description characteristic to the system voltage stability degree.更多还原