频率的时空分布对低频减载的影响研究

Research of the UFLS under the frequency characteristics of temporal and spatial distribution

基于电网网架结构、发电机组分布、机组参数及负荷类型等因素的影响,系统频率特性呈现为时空分布。由于系统频率是制定低频减载方案的依据,致使低频减载装置不能按照设计的理想状态动作。针对某地区电网解网事故,详细分析了功率缺额下系统频率的动态特性及低频减载装置的动作情况。基于频率的时空分布特性考虑低频减载装置动作后频率恢复效果、切负荷大小及切负荷类型等影响因子,分析了负荷特性对频率的影响,提出了分散切负荷和集中切大用户工业负荷的两种研究方案。研究结果阐明集中切大用户工业负荷可快速恢复系统的频率,并对居民负荷影响较小。因此,对实际电网运行、低频减载方案的制定具有重要的参考价值。

With the impact of grid structure, generators distribution, generator units parameters, and load type, the system＇s frequency characteristics presents temporal and spatial distribution. However, system frequency is the reference for formulating the UFLS scheme, which makes the action of UFLS device unsatisfactory. Based on the grid splitting in some region, this paper analyzes the dynamic characteristics of system frequency and the action of UFLS device in detail under the power shortage. Considering the impact factors such as frequency recovery effect, load shedding values and its types, etc., it studies the influence of load characteristics on frequency and proposes two research programs including decentralized load shedding and centralized cutting industrial load of large consumer. The research results show that cutting industrial load of large user can quickly restore the system frequency and have smaller influence on the residents＇ load, therefore it has significant reference value on control strategy of frequency recovery in the grid operation and making the program of the UFLS.