电力系统强迫振荡源定位的时-频域耗散能量流方法

Time-Frequency Domain Dissipation Energy Flow Method for Forced Oscillation Source Location in Power System

准确定位强迫振荡源对电力系统的安全稳定运行意义重大。然而,由于强迫振荡模式的可观性和振荡时变特征,传统方法难以从多通道量测信息中有效提取振荡分量,从而降低了基于耗散能量流的强迫振荡源定位方法的定位精度。为此,提出了一种基于耗散能量流的电力系统强迫振荡源时-频域定位方法。首先,根据节点各量测通道间信息相关性,利用同步压缩短时傅里叶变换处理节点多通道量测信息,构建节点统一时-频系数矩阵;然后,根据强迫振荡分量的能量特性,利用时-频域能量筛选并同步提取时-频系数矩阵中的时-频域强迫振荡分量;进一步,根据测量信息的时-频域特性,在传统时域强迫振荡耗散能量流计算模型的基础上推导出基于同步压缩短时傅里叶变换的时-频域耗散能量流计算模型,并根据系统强迫振荡期间的时-频域耗散能量流能量特性定位强迫振荡源;最后,将所提方法应用于WECC 179节点测试系统、WECC 240节点测试系统的仿真振荡场景以及美国New England的实际振荡事件,所得结果表明所提时-频域定位方法可快速、精准定位强迫振荡源。

The accurate location of the forced oscillation(FO)source plays a significant role in secure and stable operation of power systems.However,due to the observability and time-varying characteristics of FO modes,the traditional methods are difficult to effectively extract the FO components from multi-channel measurement information,reducing the accuracy of the FO source location methods based on the dissipation energy flow.To address this issue,a time-frequency domain location method based on the dissipation energy flow for power systems is proposed.Firstly,the short-time Fourier synchrosqueezing transform(FSST)is applied to process the multi-channel measurement information from buses,constructing a unified time-frequency coefficient matrix of buses based on the information correlation among the measurement channels of buses.Secondly,according to the energy characteristics of the FO components,the time-frequency domain energy is used to screen and synchronously extract the timefrequency domain FO components from the time-frequency coefficient matrix.Furthermore,based on the time-frequency domain characteristics of the measurement information,an FSST-based time-frequency domain dissipation energy flow calculation model is derived based on the traditional time-domain FO dissipation energy flow calculation model,and the energy characteristics of the dissipation energy flow in the time-frequency domain are used to locate the FO source during the FO period.Finally,the proposed FO source location method is applied to the WECC 179-bus test system and WECC 240-bus test system as well as the actual oscillation event in New England,USA.The obtained results show that the proposed time-frequency domain location method can quickly and precisely locate the FO sources.