环境激励下基于频域特征的扰动源定位方法

环境激励下小幅周期性扰动容易被淹没在类噪声信号中,从时域角度很难实现小幅周期性扰动的检测及扰动源定位。在分析环境激励下电力系统类噪声信号频域特征的基础上,提出了基于频域特征的小幅周期性扰动的检测与扰动源定位方法。环境激励下周期性扰动的频域表征为振荡恒定、阻尼比近似为0的振荡模式,且在该模式中扰动源所在机组的模态相位超前于其他机组。利用随机子空间辨识算法对环境激励下的类噪声响应信号进行分析,提取振荡模态及参数,根据模态个数及特征参数实现小幅周期性扰动的检测,检测到周期扰动后,根据阻尼比近似为0的周期性振荡模式的模态相位关系即可定位扰动源所在机组。IEEE 4机2区域系统和IEEE 16机68节点系统的算例结果验证了所提方法的有效性和可行性。

Disturbance source location method based on frequency-domain characterization with environmental excitation

Small periodic disturbance under environmental excitation is easy to be drowned in noise-like signals and it is hard to detect the small periodic disturbance and locate the disturbance source from the view of time-domain. Based on the analysis of frequency-domain characteristics of noise-like signals in the power system with environmental excitation, a detection and location method of small periodic disturbance based on frequency-domain characteristics is proposed. The periodic disturbance under environmental excitation is represented as an oscillation mode with constant oscillation and damping ratio approximating to zero, and the mode phase of the generator where the disturbance source belongs to in the mode is ahead of other generators. The noise-like signals under environmental excitation are analyzed by stochastic subspace identification algorithm, the oscillation modes and parameters are extracted, and then the small periodic disturbance is detected according to the quantity of modes and characteristic parameters. Based on this, the generator where the disturbance source belongs to can be located according to the modal phase relationship of periodic oscillation mode whose damping ratio is approximately zero. Simulative results of IEEE 4-generator 2-area system and IEEE 16-generator 68-bus system verify the effectiveness and feasibility of the proposed method.