Sine-Cosine Algorithm for Day-Ahead Active-Reactive Dispatch of Degradation-Aware BESS in ADNs

Abstract

The increasing penetration of renewable energy sources and the deployment of battery energy storage systems (BESSs) in active distribution networks (ADNs) introduce significant operational challenges, including high-dimensional non-convex optimization, battery degradation costs, and uncertainty in demand and generation. This paper presents a comprehensive optimization framework for the day-ahead scheduling of BESSs in ADNs, addressing the coordinated active and reactive power dispatch while explicitly accounting for battery cycling and calendar aging through a detailed rainflow-counting degradation model. The proposed methodology employs the Sine-Cosine Algorithm (SCA) enhanced with problem-specific features: an inverse incomplete gamma-based radius update mechanism for balanced exploration-exploitation, an elite population diversification strategy to prevent premature convergence, and a deterministic feasibility repair procedure to enforce state-of-charge constraints. The framework is validated on modified 33-bus and 69-bus radial distribution networks under both deterministic and uncertainty conditions, the latter represented by 100 demand and photovoltaic generation scenarios. Numerical results demonstrate that the SCA consistently outperforms three benchmark algorithms—AJAYA, Parallel Genetic Algorithm (PGA), and Multiverse Optimizer (MVO)—across all performance indicators. Under deterministic operation of the 33-bus system, the SCA achieves the lowest daily operating cost of 6,848.85 USD/day, representing savings of 4.65 USD/day over AJAYA and 15.65 USD/day over PGA. Under uncertainty scenarios, the SCA delivers the highest average cost reductions, reaching 154.34 USD/day (2.29%) for the 33-bus network and 121.79 USD/day (2.97%) for the 69-bus network, while exhibiting the lowest standard deviations (as low as 0.0492% on the 69-bus system). The results position the SCA as a robust, efficient, and economically attractive tool for practical day-ahead BESS scheduling in active distribution networks.