Sensitivity-based Sparse BESS Optimization for Voltage Violations Mitigation in Distribution Systems with High PV Penetration

Abstract

Battery Energy Storage Systems (BESS) are increasingly deployed in distribution systems (DSs) to enhance stability and improve the utilization of energy from renewable energy sources (RESs). However, their optimal sizing, siting, and operation remain open challenges. This paper proposes a novel optimization strategy for joint BESS sizing and daily charging/discharging scheduling in unbalanced distribution systems with a specified level of RES penetration, while fulfilling given voltage and state-of-charge (SOC) limits. Voltage variability is estimated using affine arithmetic (AA) based on historical data and applied to a sensitivity-based linearized DSs model. The resulting formulation relies on a relaxed continuous approach (i.e., avoiding binary variables for BESS siting) and a differentiable cost function, ensuring a good trade-off between scalability and computational efficiency. Simulations based on modified versions of the IEEE 34-bus and IEEE 123-bus DSs with different PV penetration levels demonstrate that the overall costs for Distribution System Operators (DSOs) can be minimized with just sporadic voltage limit violations and with 90% of the total BESS capacity concentrated in a few locations.