The identification of power system low-frequency oscillation modes based on measured signals is beneficial to effective control of system damping to improve the stability of the power grid. The principle of identification of the low-frequency oscillation modal parameters using Prony algorithm is described. For the appearance of the pseudo mode due to the Prony algorithm being sensitive to the noise of analyzed data and the difficulty in identifying the order of the model

a low frequency oscillation identifying method is proposed by combining difference orthogonal matching pursuit (DOMP) with Prony algorithm. The proposed method is applied in simulation of a case study on an EPRI-36 system and phasor measuring unit (PMU) data from an actual system. The results show that the low-frequency oscillation modal parameters can be accurately recognized. Comparison of the proposed method with the Prony algorithm shows that the proposed method is able to provide relatively precise analysis results up to requirement of identification of power system low-frequency oscillation modal parameters. This work is supported by National Natural Science Foundation of China (No. 50907034).