Low frequency oscillation online identification based on synchronous phasor of distribution network

With the advancement of the interconnection process of power grid, the low-frequency oscillation (LFO) problems in the interconnected power grid greatly affect the economic and stable operation of the system. In recent years, the research of synchronous measurement system of distribution network has made great progress, which makes it possible to construct a new generation of low-cost, flexible and reliable online monitoring system of low-frequency oscillation based on the synchronous phasor of distribution network (LFO-DPMU). Based on this, the physical structure and processing flow of LFO-DPMU are constructed in this paper. The LFO-DPMU can extracts dominant mode of oscillation from the distribution network information in real time. For the identification algorithm, this paper selects Prony and HHT algorithm, which two kinds of commonly used oscillation identification algorithms in high-voltage power grid, and compare the characteristics of algorithm in anti-noise, stability and analysis efficiency. Then, combined with the characteristics of distribution network signal, this paper analyses the applicability of the two algorithms. Finally, two algorithms are used to extract the oscillation mode of the measured synchronous phasor signal of distribution network. The analysis result shows the feasibility and accuracy of the whole identification system.