2019 Volume 55 Issue 9 Pages 573-581
Renewable energy sources (RES) have been introduced in power systems since the feed-in tariff (FIT) was adopted. Especially, photovoltaic (PV) power has been widely installed in western Japan, causing a surplus of power that increases the frequency of the power system. Power outputs from PVs are unstable and the estimation of the outputs is difficult. Moreover, a ramp variation of PV outputs has also been observed. The frequency fluctuation caused by the variation is severe for a stable operation of the power system. A standard power system model for automatic generation operation and control was published by the Institute of Electrical Engineers of Japan (IEEJ). The standard model was named IEEJ AGC 30 model. The power system model is utilized to evaluate the results of a frequency control objectively. This study develops an expanded IEEJ AGC 30 model which can simulate for 24 hours. Also, the study simulates a load frequency control with a ramp down phenomenon of PVs on a large demand day and a small demand day. Moreover, the study suggests some approaches to suppress the frequency fluctuation caused by a ramp down phenomenon.
