Frequency and voltage stabilization in RES and EVs integrated distribution networks using a BESS deadband-based droop control strategy

The increasing integration of Electric Vehicles (EVs) and Photovoltaic (PV) systems into distribution networks (DN) enhances sustainability but introduces challenges related to voltage and frequency stability. This paper presents a regulation framework using Battery Energy Storage Systems (BESS) governed by a deadband-based droop control strategy by Indian grid code standards. EV and PV allocations are mapped based on socio-economic and geographic parameters over two test systems: IEEE-33, mapped over the semi-urban region (30.33° N, 77.95° E), and 118-bus system, mapped over the urban area of Dehradun, India (30.29° N, 78.06° E). A Multi-Objective Differential Evolution (MODE) framework is employed for optimal BESS siting and sizing under EV penetration levels of 100%, 90%, and 80%, considering time-series system operation. In the IEEE-33 system, maximum RoCoF reduces from 0.193 to 0.113, frequency deviation decreases from 0.139 to 0.077 Hz, and IAFD reduces from 8.104 to 6.350, indicating improved damping and frequency stability. Similarly, for the IEEE-118 system, Rate of Change of Frequency (RoCoF) reduces from 0.190 to 0.111, frequency deviation from 0.136 to 0.067 Hz, and Integrated Absolute Frequency Deviation (IAFD) from 7.527 to 6.385 under 80% EV penetration. Across all scenarios, the Frequency Deviation Index (FDI) and Voltage Deviation Index (VDI) show consistent reduction, with VDI decreasing by up to 45% in the IEEE-33 system and over 50% in the IEEE-118 system, while the weakest bus voltage improves from 0.8706 to 0.9608p.u.These results validate the proposed BESS-based control framework in mitigating frequency and voltage instabilities under high EV and PV penetration in geographically diverse DNs.