Abstract
•Proposes a novel optimization framework for Volt/VAr control of smart inverters in PV–BESS integrated distribution networks.•Maximizes PV hosting capacity (PVHC) while minimizing voltage deviations through coordinated reactive power control.•Formulates a multi-objective mixed-integer nonlinear optimization problem including sizing, placement, and dispatch of PV and BESS.•Employs the Water Cycle Algorithm (WCA), demonstrating superior performance over conventional metaheuristic methods.•Validated on the IEEE 69-bus system, showing significant improvements in PV integration and overall network performance.
The increasing penetration of photovoltaic (PV) systems in distribution networks has intensified voltage regulation challenges and constrained photovoltaic hosting capacity (PVHC), necessitating advanced coordination of distributed energy resources. This study presents an integrated optimization framework for adaptive smart inverter Volt/VAr control in photovoltaic-battery energy storage system (PV-BESS) distribution networks to enhance renewable energy integration while maintaining acceptable voltage profiles. The proposed framework simultaneously optimizes smart inverter Volt/VAr control settings, PV-BESS sizing, placement, inverter oversizing, and operational dispatch within a unified optimization model to maximize PVHC and minimize voltage deviation (VD) while satisfying network operational constraints. The Water Cycle Algorithm (WCA) is employed as the optimization engine to efficiently solve the resulting multi-objective optimization problem. The framework is evaluated on the IEEE 69-bus distribution network using realistic load profiles and solar irradiance data obtained from the National Renewable Energy Laboratory (NREL). Six operating scenarios, ranging from a conventional network without PV-BESS integration to coordinated PV-BESS optimization with adaptive Volt/VAr control, are investigated to assess the effectiveness of the proposed methodology. Simulation results demonstrate that the integrated optimization framework increases the PVHC from 10.208 MW to 12.508 MW, representing a 22.53% improvement over the conventional Volt/VAr control strategy, while reducing the voltage deviation from 0.102 pu to 0.025 pu, corresponding to a 75.49% reduction. Furthermore, the optimized control strategy maintains all bus voltages within the ANSI recommended limits (0.95–1.05 pu), with voltage magnitudes ranging from 0.980 pu to 1.010 pu under the optimized operating scenario. Comparative evaluations against Particle Swarm Optimization (PSO), Genetic Algorithm (GA), Ant Colony Optimization (ACO), and Differential Evolution (DE) demonstrate that the WCA-based optimization consistently achieves superior PVHC enhancement, improved voltage regulation, and faster convergence under identical simulation conditions. These findings demonstrate that coordinated optimization of adaptive Volt/VAr control and PV-BESS operation provides an effective solution for enhancing renewable energy hosting capacity and voltage stability in distribution networks.