基于振荡相位差的低频振荡扰动源定位方法

A Method for Locating Low-frequency Oscillation Disturbance Source Based on Oscillation Phase Difference

如何快速准确地定位扰动源是低频振荡监测与控制的重要问题。分析了扰动源影响网内机组的机理,提出了一种基于振荡相位差的低频振荡扰动源定位方法。首先利用经验模态分解提取主导振荡模式的电气量数据,再经希尔伯特变换计算出具有物理意义的振荡相位,最后通过计算振荡相位差描述两点整体的振荡相位关系。根据网络信息判据可以追溯扰动源的方位,根据电厂就地信息判据可以排查具体的扰动源机组。方法原理清晰,只需一种电气量参与计算。利用华中电网实际系统进行了仿真验证,表明方法具有较好的适用性。

Quick and accurate location of the disturbance source is an important subject in the field of low-frequency oscillation monitoring and control. This paper analyzes the mechanism of disturbance source influence upon gridunits and proposes a method for locating low-frequency oscillation disturbance source based on oscillation phase difference. First,electrical data of the dominant oscillation mode is extracted through empirical mode decomposition. Then,oscillation phase with physical meaning is calculated through Hilbert transform. Finally,oscillation phase difference is calculated to describe overall oscillation phase relationship between two points. The direction of the disturbance source can be traced according to the criterion of network information,and the specific disturbance source set can be determined according to the criterion of local information about the power plant. This approach has a clear cut principle and only one electrical quantity is needed in the calculation process. Simulation verification made on the Central China Power Grid shows that this approach has good applicability.