归一化能量函数在电力系统稳定性分析中的应用-电力系统及其自动化专业论文.docxVIP

摘要随着电力系统市场化的推广和实施，现代电力系统经常要运行在接近暂态稳定安全 摘要 随着电力系统市场化的推广和实施，现代电力系统经常要运行在接近暂态稳定安全 约束边缘的状态，因而稳定约束下的系统安全极限分析受到了广泛的重视。开发适于在 线应用的暂态稳定性评估工具已成为十分紧迫的研究课题。本文主要研究了归一化暂态 能量函数(NTEF)在电力系统暂态稳定性裕度分析中的应用，为开发在线评估工具奠 定了良好的基础。 为了摆脱暂态能量函数分析中临界发电机群的束缚，本文提出了归一化暂态能量函 数的新概念。重点研究了故障后系统最小归一化动能随故障切除时间变化的关系特性， 并在此基础上提出了用于暂态稳定性裕度评估的能量平移法。基于能量平移及故障后系 统NTEF的守恒性，提出了计算稳定性故障后轨迹能量裕度的改进模板技术。该方法不 必进行假想持续故障轨迹积分，这就使稳定裕度计算和商业仿真软件结合使用变得十分 容易。 本文将NTEF稳定裕度分析的新算法应用于暂态稳定性分析策略。该分析策略能够 与商业仿真软件相结合，快速滤除无危害故障，对有危害和有潜在危害的故障计算其归 一化能量裕度(NTEM)。为了比较有危害或有潜在危害故障的稳定程度，NTEM被进 一步转化为暂态稳定时间裕度。时间裕度的概念容易被系统运行人员所接受，它还可以 用来对故障的严重程度进行排队。 在河南电网和新英格兰系统上的稳定性分析结果说明了NTEF稳定裕度分析新算法 的有效性和正确性。 关键字：归一化暂态能量函数，能量平移，改进的模板技术，稳定裕度 ABSTRACTThe ABSTRACT The worldwide trends in deregulation and open access of power system may make modem interconnected power systems more often operated close to its transient stability limits than before．Nowadays，optimal operation of modem power system under dynamic security constraints has received growing attention．There is pressing need for development of tools of transient stability security assessment(TSA)for on·line application． This thesis mainly studied the application of the normalized transient energy function邮F) to transient stability margin assessment．This is significant for developing on—line TSA tools in real industry applications． The new concept of normalized transient energy function，which is not restricted by critical generators，is presented in this paper_The variation characteristic of the minimum of normalized transient kinetic energy in the post—fault duration for a contingency versus fault clearing times has been studied．Based upou the above ckaracteristic，a hover agproach named energy translation for assessment of transient stability energy margin is proposed． Using the approach of energy translation and the property conservation of NTEF,a technique called the corrected sample—ruler technique is developed to evaluate the energy margin of stable trajectories．This method avoids the reinsert pseudo f