【作者】 徐兴伟；

【导师】 穆钢；

【作者基本信息】 华北电力大学（河北） ， 电力系统及其自动化， 2010， 博士

【摘要】 复杂电力系统普遍采用低频减载措施作为保证电网安全的最后一道防线,而掌握频率动态过程特性则是制订合理低频减载方案的基础。虽然大多数复杂电力系统采用单机带集中负荷模型设计、多机系统校核的方法开展低频减载方案整定工作,但这种方法有其适用的局限性,也难以从低频减载方案中得到维持频率稳定能力的信息,在复杂电力系统频率动态过程参数准确性没有得到认证的情况下进行低频减载方案校核,校核结果的准确性也难以保障。本文采用理论分析和时域仿真相结合的方法,研究了单机单负荷系统频率调节效应问题,分析了复杂电力系统频率动态过程研究实用化问题,以此为基础研究了复杂电力系统低频减载方案维持频率稳定的能力。在研究单机单负荷系统频率调节效应问题时,本文从单机单负荷系统模型出发,研究了单机单负荷系统频率动态过程解析方法,纠正了以往采用的单机单负荷系统频率动态过程解析解存在的错误,首次提出了基于轨迹的频率调节效应系数计算方法,研究了不同条件下的频率调节效应,完善了单机带集中负荷模型设计的低频减载整定方法。为了实现复杂电力系统频率动态过程研究的实用化,本文研究了复杂电力系统频率动态过程实用模型参数获取方法、误差评价指标、运行方式关键因素、参数调整原则等问题。根据大量复杂电力系统功率脱落事件的实测轨迹,求得到了反映实际复杂电力系统频率动态过程主要特征的实用化参数,为校核复杂电力系统低频减载方案奠定了理论和方法的基础。为检验低频减载方案维持频率稳定的能力,本文首次提出了采用集中功率脱落方式校核复杂电力系统低频减载方案防御能力的方法,并对实际复杂电力系统的维持频率稳定能力进行了检验。由此全面验证了本文提出的基于轨迹的复杂电力系统频率动态过程整体研究方法的有效性。更多还原

【Abstract】 Under-frequency load shedding (UFLS) is widely used in complex power system, which serves as the last defense line of power system security. The basic work for proper UFLS strategy is to get hold of the dynamic characteristics of frequency. Although, design of single machine with centralized load model and multiple machines checking method have been carried out for the setting work of UFLS in most complex power system, this method has its application limit. And it is also hard to achieve any information of the capability to keep frequency stability from the UFLS scheme. Under the situation that the parameters’accuracy is not certified in the dynamic process of frequency, the checking results’acuracy of UFLS scheme can not be guaranteed.In this paper, theoretical analysis and time domain simulation methods were combined to research the frequency regulation effect problem of single-load and single-machine system. The practical use of dynamic frequency process research on complex power system was analyzed, on the basis of which, the keep capability of frequency stability by UFLS scheme for complex power system was researched.In the research on the frequency regulation effect problem of single-load and single-machine system, analytical method was researched on the dynamic frequency process of single-load and single-machine system from its mathematical model aspects. The analytic solution errors of the former research were corrected on the dynamic frequency process problem of single-load and single-machine system. The coefficients calculation method of frequency regulation effect based on the frequency trajectory was put forward for the first time. The frequency regulation effect under different situations was also researched, which improved the setting work of UFLS scheme in single machine system with centralized load model.In order to make it practical for the dynamic frequency process research for complex power system, research was carried out on the problems of the acquisition of practical models and parameters, error evaluation index, the key factors of operation, the adjustment principle of parameters and so on. The practical parameters have been achieved according to a large number of actual trajectories of frequency fluctuation events of complex power system, which reflected the principal character of the dynamic frequency process in real complex power system. And this work has laid the technical and method foundation for UFLS scheme checking of complex power system.To check the capability of keeping frequency stability by UFLS scheme, a checking method was proposed for the first time, which used the centralized power shedding mode to check the defense ability of UFLS scheme for complex power system. And the test work was also carried out on the capability problem of keeping frequency stability in a real complex power system. All of above fully verified the effectiveness of the whole research method based on frequency trajectory on the dynamic frequency process problem for complex power system.更多还原