Unit commitment risk evaluation of power systems with PV and energy storage

Abstract

As Photovoltaic (PV) penetration level rapidly increases in the modern power systems, the adoption of energy storage systems (ESS) is a preferred option to control the rapid and unpredictable PV power fluctuations. It is desired to develop new reliability evaluation methods that can model and evaluate the reliability impact of these new entries. This paper has proposed an area risk based method that can take into account the PV intermittence and ESS operations when evaluating the unit commitment risk (UCR). The rapid changes of PV power is accounted for every 5-minute interval during the lead time. A control algorithm for the ESS is also developed and integrated into the evaluation of UCR. The method is applied to quantify the effects of different ESS capacities on the system's load carrying capability. System planners can utilize this method to determine the proper ESS installation for a system with given PV penetration level. This method is also useful for system operators to decide on the required committed units as well as the charging and discharging power of ESS given PV fluctuation.