【作者】 易海琼；

【导师】 熊小伏；

【作者基本信息】 重庆大学 ， 电气工程， 2003， 硕士

【摘要】 临界切除时间是电力系统稳定问题分析中最重要的稳定指标之一。但现有计算方法中存在着计算速度慢，计算结果可信度值得斟酌等问题，不能满足电力系统运行、动态安全控制和维持系统暂态稳定的需要。因此，寻找更为有效的临界切除时间计算方法和发电机出力预防控制方法是必须的，对提高电力系统稳定性有极大的作用，也为日后在线控制的实现提供了可能性。本文正是着眼于上述问题，进行了大量的研究工作，提出了一种快速的能满足精度要求的临界切除时间的计算方法，并将该方法应用于发电机出力的预防控制之中。论文的主要内容如下：(1) 详细分析了现有灵敏度分析方法的不足之处，得出轨迹灵敏度分析方法适合于电力系统暂态稳定分析和动态安全控制。轨迹灵敏度分析能弥补现有灵敏度分析方法的不足之处，可以方便地考虑系统轨迹出现离散点的情形，具有较高的精度，因而十分适于电力系统暂态稳定问题的研究。(2) 在分析了电力系统暂态稳定分析方法的时域法仿真法和直接法的优缺点之后，指出暂稳分析方法的发展在于二者的结合，提出了基于轨迹灵敏度的时域法和直接法相结合的暂稳分析方法，并将该法应用于临界切除时间的计算。本文提出的基于轨迹灵敏度的CCT计算方法速度快，精度高，有在线应用的前景。(3) 针对目前事故筛选是通常将事故简单地分为稳定或不稳定，只有不稳定的事故才需要进一步详细地分析并采取相应的预防控制措施。考虑到这种分类方式的局限性，且为了便于进行暂态稳定控制，本文在事故筛选时将事故分为三类：安全、不安全、介乎二者之间，并将临界切除时间作为稳定指标来进行分类。(4) 提出了一种利用临界切除时间来实施发电机出力预防控制的方法。与以往的计算方法相比，该法简单实用，计算速度快，能满足在线预防控制的需要。(5) 为了完成以上工作，编制了暂态稳定时域仿真法程序更多还原

【Abstract】 Critical clearing time (CCT) is one of the most important stable indices in power system transient stability analysis. The existing calculation methods have some disadvantages, which can’t satisfy the need of the dynamical secure control and system transient stability analysis. So, it’s necessary to develop more effective CCT-calculating method, which will play an important role in improving power system stability, and provide possibility in realization of online control. Thorough study has been done to solve the problems. A fast CCT calculative method was suggested which could satisfy the precision need, the method was applied in the preventive control of the generator outputs. The main contents are given as following:Firstly, the existing sensitive analysis is analyzed in detail, and the thought of applying the trajectory sensitivity in transient stability analysis and dynamical security control is proposed. The trajectory sensitivity can overcome the shortages of the traditional sensitive methods, easily consider the discrete point appearing condition in the system trajectory, and hold high precision, which is fitful for the research of the transient stable analysis.Secondly, after analyzing the advantages & faults of time-domain simulation and the direct methods, this paper points out the key of developing the transient stable methods is the integration of both. The CCT-calculating method is presented which is based on the trajectory sensitivity and the hybrid method. And the time-domain simulation program has been programmed. The way proposed in the thesis has many advantages such as fast calculation speed, high calculation precision and promising online application. Thirdly, The contingency screening is classified as security and insecurity; only the insecure contingency needs detailed analysis and corresponding preventive control measures. After considering the localization of the traditional classified method, the paper proposes a screening method that the contingencies are sorted into three types: security, insecurity and the status between the two conditions, which is fit for preventive control. So the preventive control can be realized easily.Finally, A method that can accomplish the generation rescheduling preventive control is presented. Compared with other traditional calculative methods, the method in this thesis is simple, has fast calculation speed and can satisfy the need of on-line preventive control更多还原