大规模互联电网频率动态分析

发布时间：2018-06-15 00:39

本文选题：电力系统 + 频率响应　；参考：《西南交通大学》2017年硕士论文

【摘要】：频率是电力系统运行的关键参数之一。目前,我国已形成了全国性的区域互联大电网。区域电网互联在提高系统频率稳定性的同时,也增加了恶性连锁事故的危害性。当系统发生频率失稳后,其影响可通过联络线扩大,严重时将造成大面积停电事故。电力系统频率动态特性分析是进行频率稳定分析与控制的基础。本文主要从电力系统频率分析方法和区域频率动态特性等方面进行分析与研究。论文归纳建立了一种适用于两区域电网的区域频率计算模型。该模型结合了单机等值模型法和线性化方法的特点,通过等值和网络收缩将原复杂电力系统简化为含扰动节点的两区域三节点系统,在复频域建立了等值简化系统的频率代数方程,给出了区域频率的复频域表达式,其原理明确,计算量小。论文还提出了一种基于直流潮流模型的电力系统动态频率解析解计算方法。该方法基于有功主导频率动态的特点,采用直流潮流法近似描述系统网络,考虑了原动机-调速器动态和负荷频率特性等对系统频率动态变化的影响,且保留了一定的解析特性,不需要逐步积分。其解析解分离了动态频率的振荡部分和稳态部分,振荡部分给出了各振荡分量的频率、幅值、相角、衰减因子等参数,稳态部分能直接确定扰动后系统的稳态频率。通过与PSS/E仿真结果比较,该方法能够准确描述系统频率的动态特性。论文最后研究了互联电网区域频率的动态特性。基于IEEE 118母线改进系统,分析了区域频率的时空分布特性以及功率频率特性的影响因素,并研究了不同区域之间存在的区域频率相互影响的现象。
[Abstract]:Frequency is one of the key parameters of power system operation. At present, China has formed a nationwide regional interconnected power grid. Regional power grid interconnection not only improves the system frequency stability, but also increases the harm of malignant chain accidents. When the frequency of the system is unstable, the influence can be extended through the tie line, and a large area of power outages will be caused when it is serious. Frequency dynamic characteristic analysis of power system is the basis of frequency stability analysis and control. In this paper, the frequency analysis method and regional frequency dynamic characteristics of power system are analyzed and studied. In this paper, a regional frequency calculation model for two regional power grids is established. The model combines the characteristics of the single machine equivalent model method and the linearization method, and simplifies the original complex power system into a two-region three-node system with disturbance nodes through equivalence and network contraction. In the complex frequency domain, the frequency algebraic equation of the equivalent simplified system is established, and the expression of the region frequency in the complex frequency domain is given. The principle is clear and the calculation is small. This paper also presents an analytical solution method for power system dynamic frequency based on DC power flow model. Based on the dynamic characteristics of active power dominant frequency, the DC power flow method is used to approximate describe the system network, and the influence of the prime mover governor dynamics and load frequency characteristics on the system frequency dynamic change is considered. Moreover, some analytical properties are retained, and no step integral is required. The analytical solution separates the oscillation part of the dynamic frequency from the steady part. The oscillation part gives the frequency, amplitude, phase angle, attenuation factor and other parameters of each oscillation component. The steady-state part can directly determine the steady-state frequency of the system after disturbance. Compared with PSS / E simulation results, this method can accurately describe the dynamic characteristics of the system frequency. Finally, the dynamic characteristics of the regional frequency of interconnected power system are studied. Based on the IEEE 118 bus improvement system, the spatial and temporal distribution characteristics of regional frequencies and the influence factors of power frequency characteristics are analyzed, and the phenomenon of regional frequency interaction between different regions is studied.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM712

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