Multi-stage Robust Reactive Power Optimization in Active Distribution Networks with Discrete Intertemporal Constraints

• Published in: IEEE transactions on power systems Vol. 40; no. 5; pp. 1 - 14
• Main Authors: Guo, Zhongjie, Wei, Wei, Cao, Xiaoyu, Hu, Weihao
• Format: Journal Article
• Language: English
• Published: IEEE 01.09.2025
• Subjects: Couplings; Decision making; distribution network; Distribution networks; Load flow; Mathematical models; multi-stage robust optimization; non-anticipativity; Optimization; Reactive power; Reactive power regulation; Regulation; Renewable energy sources; Uncertainty
• ISSN: 0885-8950; 1558-0679
• DOI: 10.1109/TPWRS.2025.3543358

Reactive power regulation is crucial for active distribution networks (ADNs). This paper studies the multistage reactive power optimization in ADNs with renewables considering intertemporal constraints imposed on total action times of discrete regulation facilities. First, we regard reactive power regulation as a sequential decision-making process and formulate it as a multi-stage robust optimization problem with hybrid continuous and discrete recourses. Then, we propose a customized implicit policy method to solve this problem, devising bounding variables and non-anticipative constraints of shunt capacitor bank (SCB) and on-load tap changer (OLTC). Next, the bounding variables are optimized prior to dispatch subject to non-anticipative constraints; with their help, intertemporal couplings are broken and the multi-stage robust optimization problem shrinks to a two-stage robust one, which can be solved by decomposition algorithms. Finally, we use the bounding variables to build a non-anticipative and robustly feasible policy based on time-decoupled optimal power flow (OPF) where intertemporal constraints are relaxed but satisfied at the optimums. Case studies on the modified IEEE 33-bus, 69-bus, and 123-bus systems verify the advantages of the proposed method.