Optimal Power Flow with energy storage systems: Single-period model vs. multi-period model

The inherently intermittent nature of wind power has posed challenges for the increasing integration of this generation source into power systems. A possibility for mitigating this difficulty is the use of large-scale energy storage systems (ESSs) such as battery energy storage (BES). ESSs could be used for providing an economic utilization of wind power by displacing the low cost wind energy during off-peak periods to more expensive energy during peak periods. ESSs can also be used for either reducing fluctuations from wind generation or alleviating transmission line congestions by charging the surplus wind power at high wind periods and then discharging to supply demand during low wind periods. In this paper, we formulate an AC Optimal Power Flow (OPF) problem with BES within single-period and multi-period models. Then, we discuss and compare the optimal combined operational schedules of BES and wind generation in both models, testing the procedure on IEEE 14-bus and IEEE 57-bus case studies.