Abstract
High penetration of PV systems has a challenge for power system stability due to the PV short-cycle fluctuations and the PV output forecast error. The countermeasure against the PV output forecast error is unit commitment considering the reserved capacity such as LFC capacity. Generally, the constant LFC capacity is known regardless of the PV fluctuations. LFC capacity is required in accordance with the PV output forecast error for more PV installation capacity. Then, this paper proposes a dynamic determination method of LFC capacity at each time in a unit commitment by estimating the range of PV output forecast error. Firstly, a PV output forecast error statistical data was made for estimating the range. Secondly, an equation of the LFC capacity for the PV output forecast error was formulated. Finally, the unit commitment was planned by estimating PV output forecast error and dynamically determining the LFC capacity. The result of the proposed method showed that the maximum PV installation capacity could be increased from 56.5% to 71.6% compared to the static setting of LFC capacity. Furthermore, LFC capacity was reduced from 391 MWh to 295 MWh.
