考虑暂态频率特性的孤立电网低频减载方法  

An under-frequency load shedding method adapted to isolated power grids considering transient frequency characteristics

作　　者：靳希[1] 沙旦华[1] 曹炜[1] 张菲菲[1] 祁晓卿[1] 

机构地区：[1]上海电力学院电力与自动化工程学院,上海200090

出　　处：《电力科学与技术学报》2011年第4期69-73,共5页Journal of Electric Power Science And Technology

基　　金：国家自然科学基金(50907039);西藏电力有限公司科技项目(SJB-2010-001);河北电力公司科技帮扶项目(KJ-2010-112);上海市科委国内科技合作项目(11195802200)

摘　　要：针对孤立电网运行频率波动范围较大且负荷有限的特点,提出一种考虑系统暂态频率特性的孤立电网低频减载方法.该方法采用较低的频率启动值及较少的启动轮次;根据实际系统暂态频率特性,对于频率启动值较大的轮次,采用较长的动作时限;并采用最低频率轮先动作其他轮间并行或的动作逻辑;且在特殊情况下,采用低频减载与快速连切负荷相结合的措施确保系统频率稳定.应用实例分析表明该方法能在很大程度上提高低频减载的有效性,避免低频减载装置无谓动作,有利于孤立电网运行的安全稳定.According to large frequency fluctuation range and limited load in the operation of isola- ted power grids, an under-frequency load shedding method adapted to the isolated grid is presen- ted in this paper with transient frequency characteristics considering. The method adopts lower frequency starting value and less starting rounds. Based on the transient frequency characteristics, longer tripping time is used at higher frequency starting value. The lowest frequency round operates first, and others operate in parallel. In particular conditions, an under-frequency load shedding （UFLS） with accelerated load shedding method is used to ensure the stability of frequency. The application example analysis results shows that the method can improve the efficiency of under frequency load shedding, avoid unnecessary operation of the UFLS device, which has great significance for the stable operation of isolated grids.

关 键 词：孤立电网 低频减载 频率波动 暂态频率特性 

分 类 号：TM74[电气工程—电力系统及自动化]