【作者】 邵锐；

【导师】 刘宪林；

【作者基本信息】 郑州大学 ， 电力系统及其自动化， 2005， 硕士

【摘要】 现代电力系统的发展,对小扰动稳定研究提出了更高的要求。本文围绕基于解耦模型的多机电力系统小扰动稳定降阶分析和控制问题开展了以下工作:提出了多机电力系统的解耦降阶法,并基于此方法实现了多机系统小扰动稳定分析的频域降阶分析;基于解耦降阶法进行多机系统的PSS设计,并与传统设计方法进行比较;分别用特征值分析法和解耦降阶法对某区域电网的小扰动稳定性进行了分析,并提出改善稳定性的措施;编制了MATLAB多机电力系统小扰动稳定分析程序以及基于解耦降阶法的PSS设计程序。 本文提出了多机电力系统小扰动稳定分析的一种频域解耦降阶法。基于该方法从两个方面实现了多机系统小扰动稳定的频域降阶分析:通过偶极子对消的方法可以直观得到各机组的闭环主导极点:籍助各解耦单机系统的开环频率特性曲线和开环频域性能指标直观地分析多机系统的绝对稳定性和相对稳定性。该方法不仅实现了多机系统线性化模型的降阶,而且不会出现丢失系统主导极点的现象,同时解耦机组的稳定裕量或主导极点阻尼比还可直接为改善系统稳定性提供明确的信息。 本文对基于振荡模式分析的PSS设计方法进行改进,并提出了一种基于频域解耦降阶模型的PSS设计方法。改进的振荡模式设计法,不再需要对安装PSS的机组作单机无穷大系统等值,而是以多机系统线性化系数矩阵K₁～K₆的对角线元素代替单机无穷大系统线性化模型的线性化系数K₁～K₆进行计算,这一方法避免了对安装PSS的机组进行单机无穷大系统等值的困难。基于解耦降阶模型的PSS设计方法,完整地计及了其它机组对PSS安装机组的影响,并通过这种方法证实了改进的振荡模式设计法的合理性。 本文在K₁-K₆模型和C₁-C₁₅模型下,分别应用中国电科院PSASP程序和自编MATLAB程序对某区域62机428节点电力系统的小扰动稳定性进行分析,提出了PSS装设方案。结果表明,解耦降阶法与特征值法的计算结果相一致,所设计的PSS效果良好。更多还原

【Abstract】 With the development of power system, the research standard on the small signal stability needs to improve. In this thesis, the researches about small signal stability reducing-order analysis and control method for multi-machine power system based on decoupling and reducing-order model are as follows. A decoupling and reducing-order method is brought forward to analyze the small signal stability of multi-machine power system. Then the reducing-order analysis based on the method in frequency domain is realized. Scheme of PSS of multi-machine power system is devised using the decoupling and reducing-order method and compared with the result of the traditional method. The small signal stability of a region power system is analyzed by the eigenvalue method and decoupling and reducing-order method. And the scheme of improving the stability is introduced. The program of small signal stability analysis of multi-machine power system and devising PSS based on the decoupling and reducing-order method is compiled using MATLAB.In this thesis, a decoupling and reducing-order method is brought forward to analyze the small signal stability of multi-machine power system. Based on the method, the reducing-order analysis in frequency domain is achieved from two ways. The closed-loop main poles of each single-machine are attained intuitively by the pole-zero cancellations. The absolute and relative stability of multi-machine is analyzed intuitivelly using the open-loop frequency characteristic charts and the performance index of open-loop frequency domain of each decoupling single-machine. The method could not only realize reducing-order of the linearization model of multi-machine power system, but also avoid losing the main poles of the system. At the same time, stability margins and damping coefficient of main poles of the decoupling machines could provide definite information for improvement of the system stability.In this thesis, the oscillation model method is improved, and a method of design of PSS of multi-machine power system is put forward based on the decoupling and reducing-order model. The improved oscillation model method is not at single-machine infinite-bus equivalence system, but diagonal elements of the linear coefficient matrix K1 ~ K6 of multi-machine system replace the linear coefficient matrix K1 ~ K6 of single-machine infinite-bus equivalence system. The method avoids the difficult ofsingle-machine infinite-bus system equivalence. The method of design of PSS of multi-machine power system based on the decoupling and reducing-order model takes the influence into account in full that the machines with PSS are subject to from others. The rationality of the improved oscillation model method is verified by the method.The small signal stability of a region power system with 62 machines and 428 buses is analyzed using the program "PSASP" of Electric Power Research Institute China and MATLAB program by myself under K1-K6 model and C1-C15 model. Then the scheme of PSS is brought forward according to the result of analysis. The result implies that the calculation result of the decoupling and reducing-order method is coincident with the result of the eigenvalue method, and the effect of the PSS is favorable.更多还原