动作延时对低频减载装置减载效果的影响  

Impact of the Time Delay on the Effect of Underfrequency Load Shedding

作　　者：李晔[1] 张保会[1] 

机构地区：[1]西安交通大学电气工程学院,陕西省西安市710049

出　　处：《智能电网》2015年第5期405-409,共5页Smart Grid

摘　　要：近年来国际上发生的几起重大的频率失稳事故说明,目前的低频减载装置由于动作门槛值、延时和切负荷量固定,容易造成负荷的过切或者欠切,进而造成频率失稳。在对频率动态特性进行分析的基础上,详细仿真研究延时对低频减载动作效果的影响。仿真结果说明:延时对低频减载装置的减载效果是否会产生影响,主要取决于系统有功缺额大小;而延时对低频减载装置减载效果的具体影响,主要由扰动发生地点所决定。由于延时的改变可能对低频减载装置的减载效果产生较大影响,因此,根据系统的运行状况实时地对低频减载装置的延时进行调整,将有利于加强系统的频率稳定性。Recently, the worldwide accidents of frequency instability have showed the disadvantages of underfrequency load shedding(UFLS) devices such as settled threshold, constant time delay and fixed load curtailments which may result in frequency instability by executing insufficient or excessive load curtailments. Based on the analysis of frequency dynamics, the influence of the time delay on the effect of UFLS is analyzed. Simulation results show that whether the time delay has influence on the effect of UFLS mainly depends on the magnitude of the active mismatch power, while the detailed influence of the time delay on the effect of UFLS mainly depends on the disturbance location. The change of time delay may have obvious influence on the effect of UFLS; therefore, to strengthen the frequency stability of the power system, the time delay of UFLS devices could be adjusted in real time according to the practical operating condition of the power system.

关 键 词：低频减载 延时 有功缺额 扰动地点 

分 类 号：TM712[电气工程—电力系统及自动化]