Multi-criterion integrated method for low-frequency oscillation-type identification

摘要

Low-frequency oscillation is one of the major threats to power system security. Online analysis and control decision system for low-frequency oscillation is in urgent need. Natural oscillation and forced oscillation are two types of low-frequency oscillation. Different oscillation types need different treatment measures. Thus oscillation-type identification is an important part of the defense system. A new multi-criteria integrated method for identifying low-frequency oscillation type is proposed. It has multiple criteria and overcomes the shortcomings of the previous single-criterion method which has low accuracy. It chooses harmonic content, characteristic index of starting oscillation waveform, and the startup-stage intrinsic damping ratio together with noise response damping ratio as criteria. The flowchart of the method is provided. The effectiveness of the multi-criteria integrated method is verified by real-power grid simulation cases. The results show that the method can reliably distinguish the low-frequency oscillation type and is practical in the real-power system.