Power systems inertia evaluation associated with PV installation by frequency analysis of inter-area oscillation based on phasor measurements

摘要

Recently, RES (renewable energy sources) have been introduced to realize a low carbon society. Installation of PV (Photovoltaics) is especially noticeable recently. RES, however, do not have inertia. If such sources increase, their influence on power system oscillations is a concern. Then, PMU (Phasor Measurement Unit) has been remarked to grasp a variable power system condition. In this study, changing of equivalent inertia of the power system is evaluated by identifying center frequency of inter-area oscillation derived by phasor difference frequency analysis using synchronized phasor information obtained from PMU. The center frequency is estimated by frequency analysis using FFT (Fast Fourier Transform) and inverse FFT. The result is evaluated quantitatively with reference to information of supply power and cumulative installation of PV. Additionally, the relationships between the center frequency and supply power or amount of global solar radiation are shown statistically.