考虑发电机控制装置的低频振荡定位及识别方法

负阻尼振荡和强迫功率振荡是两种典型的低频振荡,发电机的控制装置包括励磁系统和调速系统是振荡的两大能量注入源,其引发振荡的机理有本质的区别。因此,准确定位和识别振荡源对采取合理的抑制措施,提高系统稳定性有较大的参考价值。提出了一种根据发电机控制装置对系统阻尼的贡献以及强迫扰动源的相移特性进行振荡源定位及识别的方法。首先,深入到发电机励磁系统和调速系统,提炼出两种振荡下其内部电气量响应的一般规律;其次,在此基础上提出低频振荡源定位和识别判据;然后,进一步根据定位和识别判据原理,采用经验模态方法分解得出了判据指标的计算方法;最后,给出了发电机控制装置振荡源定位及识别方法流程。实际算例验证了所述方法的可行性和有效性。

Location and Identification Method for Low Frequency Oscillation Source Considering Control Devices of Generator

Negative damping oscillation and forced power oscillation are two typical kinds of low frequency oscillation(LFO). The control devices of the generator including the governor and the exciter are the main source of oscillation, which have essential differences to cause LFO. Thus locating and identifying the source of LFO correctly is of great importance to the adoption of reasonable suppression methods and improvement of system stability. This paper presents a method to locate and identify the LFO sources based on the contribution of the generator control devices to the system damping and the phase shift characteristics of the forced disturbance source. Firstly, based on the study of the generator control devices, the general rules of the electric parameters response of two kinds of oscillation are extracted. Then the criteria of LFO source location and identification is presented. And according to the principle of the location and identification criteria, the calculation method of the criterion index based on empirical mode decomposition(EMD)algorithm is proposed. Finally, the oscillation source location and identification method flow is made to realize the location and analysis of the oscillation sources. The feasibility and effectiveness of the proposed method are verified by practical examples.