提出一种基于WAMS/PMU技术的电力系统稳定器(PSS)在线评估方法,给出了判断PSS控制效果的评估指标,该指标综合了PSS增益和相移对控制效果的作用。PMU连续采集待评估机组的输出及其PSS/励磁的控制输出;低频振荡时,WAMS通过高速通信网络采集机组和电网的PMU录波信号,并采用Prony算法对其进行分析,得到各主导振荡模式及其对应PSS输出信号和开环系统的幅频、相频特性,计算各模式的评估指标。对两机等值系统进行了仿真实验,实验结果验证了所提方法的有效性。
A method of online PSS(Power System Stabilizer) evaluation based on WAMS / PMU technology is proposed and an index integrating the PSS gain and phase precession is given to evaluate the control effect of PSS.The outputs of the evaluated unit and the control outputs of its PSS / excitation are collected by PMU continuously and sent to WAMS via high-speed communication net when low-frequency oscillation occurs.The recorded data are then analyzed by Prony algorithm to obtain the dominant oscillation mode and the outputs of corresponding PSS,as well as the amplitude-frequency and phase-frequency characteristics of corresponding open-loop system,and the evaluation index of each mode is calculated.Simulative experiments are carried out on a two-machine equivalent system and the results verify the effectiveness of the proposed method.