【作者】 常勇；

【导师】 徐政；

【作者基本信息】 浙江大学 ， 电力系统及其自动化， 2007， 博士

【摘要】 随着“全国联网、西电东送”战略的进一步实施，不远的将来我国将形成全国性的交直流混合电网。随着跨区输送功率的不断增大，一些重大技术问题开始暴露出来，其中低频振荡成为限制交换功率的瓶颈之一。科学技术的发展将广域测量系统(Wide Area Measurement System,WAMS)等新技术、新装备引入到电力生产过程中，给电力系统安全稳定控制的发展带来了新的契机。在这样的工程背景下本文从电力系统低频振荡的广域控制和广域监视两个方面入手进行研究。首先，提出了扩展留数比的概念，选择广域信号或者是广域信号间的最佳组合作为低频振荡阻尼控制器的输入。从系统的可控性和可观性分析出发推导了扩展留数比的定义；提出了基于测试信号法的广域信号扩展留数的计算方法；在计算了不同工况下的扩展留数后选取一个基准状态并相对它求出其余工况下的扩展留数比，据此进行反馈信号比较选择。其次，探讨了基于SVC和广域反馈信号阻尼区域间低频振荡的控制器设计方法。分析了SVC提供系统阻尼的原理；基于扩展留数比选择最佳广域反馈信号；采用极点配置的方法选择广域阻尼控制器的时间常数及放大倍数；基于四机两区域系统和新英格兰10机39节点系统验证了SVC广域阻尼控制器的有效性。第三，讨论了利用柔性直流输电系统(VSC—HVDC)附加功率控制设计广域阻尼控制器的可行性。在研究了交直流电力系统机电暂态仿真中的柔性直流输电系统模型的适用性后，基于扩展留数比选择最佳广域反馈信号。研究发现互相振荡的两区域中，机组间的转速差是理想的反馈信号。采用极点配置的方法选择广域阻尼控制器的时间常数及放大倍数，借助四机两区域系统验证了广域阻尼控制器的有效性。第四，尝试利用高压直流输电系统结合滑模控制和模糊控制理论设计了广域阻尼控制器。广域测量系统提供的数据实时计算确定滑模控制的切换面；在此基础上形成一个基于模糊规则的广域阻尼控制器；通过在四机两区域系统上的数值仿真验证了该控制器的有效性。第五，引用时滞稳定性定理设计了电力系统广域时滞稳定控制器。将待研系统线性化获得描述系统动态的状态方程。为了方便设计，对该高阶系统进行降阶处理，然后通过LMI设计方法获得反馈控制器参数，时域仿真和小扰动分析均证明了该控制器可以在干扰和时滞并存的情况下阻尼区域间低频振荡。最后，从工程应用的全局出发探讨了以广域测量为基础的低频振荡监测和控制中心架构，提出了综合利用ESPIT方法和Prony方法实现在线辨识低频振荡的系统算法。提出一种自适应定阶方法以期获得辨识精度和辨识速度的最优解决方案，利用测试系统故障后扰动曲线的辨识验证了算法的有效性。更多还原

【Abstract】 In order to realize ideally resource dispatch, China is carrying through the construction of the grid. With the application of nation-wide power grid interconnection and China’s power transmission from the West to the East, a national hybrid AC/DC power grid will be formed in the future. On one hand, this will bring some technical problems, such as low frequency oscillation which has been the bottleneck of improving the power transmission. On the other hand, with the progress of the wide area measurement system(WAMS) technology, we get new chance to improve the control of modern power system. This work of thesis is going on under such background, and the main works are organized as follows.Firstly, the idea of extended residue ratio(ERR) is brought out to choose the best global signal or its combination as the input of the damping control. The paper deduce the principle of the ERR based on the controllability and observability. The test signal method is adopted here to calculate the ERR when dealing with a big system.Secondly, the SVC is introduced here to be utilized to damp the oscillation with the global signal as its control input. The principle of the SVC supplement damping control is discussed. The ERR is adopted to choose the best control input. According to the pole placement method, the time constant and the gain of the controller are determined. Time domain simulation and small signal analysis on several examples testify the effectiveness of the supplementary controller.Thirdly, the VSC-HVDC supplementary controller with the global feedback signal is designed. After study of the VSCDCT model of the PSS/E, the validity is proved. Then the global damping controller is designed based on the ERR. According to the pole placement method, the time constant and the gain of the controller is determined. The act of the controller is tested based on an example.Fourthly, a supplementary damping controller of HVDC is suggested based on sliding mode control and fuzzy control theory. The switch surface of the sliding mode is determined online by the WAMS. According this a fuzzy logic rule set is formed. The controller acts well according to the rules.Fifthly, the time delay system stability theory is introduced in the controller design process to accommodate the time delay during the transmission of the global signal. The low order system is deduced, and the controller parameters are calculated by the LMI method.Lastly, the main frame of the modern low frequency oscillation monitor and control center is built up according to the real engineer need. The low frequency oscillation is monitored online according to the ESPRIT and Prony analysis method. An adaptive arithmetic is suggested which can determine the model order during the identification process. In this way both the identification accuracy and the speed can be compromised. The arithmetic is tested on some cases.更多还原