考虑负荷频率调节系数的低频减载方案研究

Study of Low Frequency Load Shedding Project Considering Load Frequency Regulation Coefficient

电力系统的严重事故会使电压和频率恶性下降,并可能导致系统崩溃.低频减载是电力系统防止频率过度下降、维持系统频率稳定的有效方法.针对现有UFLS(低频减载)装置在动作的过程中没有充分考虑KL(负荷频率调节系数)值的不同,提出了一种新的考虑KL的低频减载方案.该方案利用频率下降时,负荷自身吸收的功率也下降的特点,在基本级优先切除KL小的线路,以利于系统频率的快速恢复和系统稳定;在特殊级优先切除KL大的线路,可尽量减少负荷的损失.同时对方案的实现进行了详细的介绍及数字仿真,仿真结果验证了该方案的合理性.

Serious outages in power system may cause drop in voltage and frequency, even collapse of system, low frequency load shedding is effective for preventing excessively drop in frequency and this can keep system frequency stably. Based on existed UFLS devices without considering the difference of KL values during movement, this paper purposed a new low frequency load shedding project. The power absorbed by the load drops when frequency declines. Using this characteristics, lines with little KL is preferentially cleared up in basic level, which is helpful for system frequency fast restoration and system stability; in order to decrease load loss, lines with big KL are preferentially cleared up in special level. At the same time, realization of project is introduced in detail and simulated. The result of simulation validates the rationality of the project.