Development of Wide Area On-line Stability Monitoring System

由于电力系统的规模和复杂性日益增大，以及电力需求的高速增长，电力系统的稳定裕度往往较低，因此，实时稳定监测对于电力系统的可靠运行变得越来越重要。在本项目中，提出了一种基于FFT的实时稳定监测方法，用于电力系统振动的频域模态分析。所提出的实时监测系统是利用个人计算机和DSP板搭建的，DSP板具有AD转换接口，用于测量实际功率流以识别振荡模式。实功率信号通过AD转换接口记录到DSP板的存储器中，并利用存储的实功率信号序列在DSP板上实时进行FFT分析。将FFT分析结果传递到Matlab/Simulink环境下的工作空间，利用颜色映射对振荡模式进行可视化，实时显示振荡模式的变化。此外，还对实测的实际潮流进行了基于模糊推理的振动模态分解，以提取实际潮流中包含的振动模态。为了更好地理解所研究系统的电力系统振荡，我们进行了相干分析。所有程序都是在Matlab/Simulink环境下开发的，用于实时模态分析的整个过程。该系统已在九州电力系统500kV变电站的500kV干线上进行了潮流信号测试。

Due to the increasing size and complexity of electric power systems, and also owing to the high rate of growth of electric power demand, electric power systems are often operated in a lower stability margin, therefore, real time stability monitoring is becoming more important for the reliable power system operation. In this project, a FFT based real time stability monitoring has been proposed for the modal analysis of power system oscillations in the frequency domain. The proposed real time monitoring system is set up by using a personal computer with a DSP board, which has an AD conversion interface for the measurements of real power flows to identify oscillation modes. The real power signal is recorded in the memory on the DSP board through the AD conversion interface and a sequence of stored real power signal is utilized for the FFT analysis in real time on the DSP board.. The result of FFT analysis is passed to the workspace in the Matlab/Simulink environment for the visualization of the oscillation modes using color mapping to show the variation in real time. In addition, a fuzzy reasoning based decomposition of individual oscillation modes has been performed to extract individual modes included in the measured real power flows. To have better understanding of power system oscillations in the study system covering a wide area, a coherency analysis has been performed. All the programs have been developed in the Matlab/Simulink environment for the entire process of the real time modal analysis. The proposed system has been tested by using power flow signals on 500kV trunk lines measured at 500kV substations in the Kyushu Electric Power System.