METHOD FOR IDENTIFYING NEGATIVE DAMPING LOW-FREQUENCY OSCILLATION BASED ON MOMENT DECOMPOSITION METHOD

摘要

The present invention relates to the field of power systems, and in particular to an implementation method for identifying the negative damping low-frequency oscillation problem caused by a generator excitation control system based on a moment decomposition method. The implementation method includes: calculating a generator secondary transient potential E' q and determining a generator speed deviation ∆omega, wherein the generator speed deviation ∆omega is acquired through the frequency calculation of the intra-generator potential EQ, and judging that the damping provided by the excitation system in the generator set to a certain oscillation mode in an interconnected grid is positive or negative by comparing the phase relationship between the generator secondary transient potential ∆E' q and the generator speed deviation ∆omega. The method is convenient for measurement and accurate and can identify a generator excitation control system which provides a negative damping to a certain negative damping oscillation mode simply and briefly, so as to rapidly suppress the low-frequency oscillation, which has been pioneered in China.