A novel SSO parameters identification technique for power grid with high proportion renewable energy using synchrophasor data

Abstract In recent years, the surge in renewable energy generation makes the operation status of power systems more complex and the possibility for the occurrence of subsynchronous oscillations (SSOs) increases. These may pose a major risk to equipment safety and system stability, leading to a potential generator tripping. Accurate and rapid identification of SSO parameters is the key to establishing mitigation measures. To utilize synchronized measurement data, improve the calculation accuracy and reduce the influence of spectrum leakage and fence effect. This paper proposes a novel technique to directly and fully determine the SSO parameters (frequency, damping factor, magnitude and phase), using the feature of linear superposition of synchrophasors in frequency domain. First, the spectrum of windowed synchrophasor data under the SSO is analyzed. The characteristics and representation of the SSO signal, as well as the fundamental frequency component in the synchrophasor are obtained. Then, the Hann-windowed three-point interpolated method is introduced to effectively suppress spectrum leakage and fence effect to accurately estimate SSO parameters. The performance of the proposed method is verified by testing synthesized and simulated signal. Results show that the proposed method can maintain high accuracy under off-nominal, dynamic, and noisy conditions. Compared with the existing latest method, the advantages and innovations of the proposed method in parameter identification are demonstrated.