Publication - Proceedings Article A Hierarchical Volt-var Optimization with Discrete Variables in Unbalanced Distribution Systems DOI https://doi.org/10.1109/pesgm40551.2019.8973834 Conference Proceedings 2019 IEEE Power & Energy Society General Meeting (PESGM), 2019 Authors Quan Nguyen, Keng-Weng Lao, Surya Santoso, Pisitpol Chirapongsananurak Language English