Renewable Energy-Based Smart Power Systems: Coordinated Control and Performance Assessment

The increasing integration of renewable energy sources into distribution networks requires coordinated control and energy management strategies to ensure reliable, efficient, and cost-effective operation. This study presents an integrated framework combining solar photovoltaic and wind generation, battery energy storage (BES), inverter-based reactive power support, and coordinated on-load tap-changer (OLTC) control. The IEEE 33-bus radial distribution network, with a total demand of 3.715 MW and 2.300 MVAr, is used to evaluate three operating scenarios: conventional grid-based operation, renewable energy integration without coordinated control, and coordinated operation using the proposed framework. A 24-hour simulation framework incorporates renewable generation and demand profiles, battery scheduling, backward/forward-sweep AC power flow, voltage assessment, operating cost evaluation, grid-related carbon emissions estimation, and dynamic frequency response analysis. The results demonstrate improvements in network performance under coordinated operation. Daily grid energy imports decrease from 70.206 to 50.843 MWh, a reduction of 27.58%, while peak grid import decreases from 3.926 to 2.895 MW. Daily feeder energy losses decline from 2.928 to 1.157 MWh, representing a 60.47% reduction. The minimum bus voltage increases from 0.9038 to 0.9626 p.u., eliminating hourly voltage violations below 0.95 p.u. Daily operating costs decrease by approximately 27.01%, while grid-related carbon emissions decline by 27.58%, based on the assumed emission factor. Furthermore, the frequency nadir improves from 49.732 to 49.910 Hz, and the peak rate of change of frequency decreases from 0.569 to 0.112 Hz/s. These findings highlight the potential of coordinated renewable generation, battery storage, inverter-based reactive power support, and OLTC control to enhance voltage regulation, reduce energy losses, and improve the technical, economic, and environmental performance of renewable-rich distribution networks.