Hierarchical and Droop Method for DC Micro-grid Bus Voltage under Isolated operationXiangyang Yan, Ningkang Zheng, Yilong Kang, Huanruo Qi, Kai Li, Haowei Pei and Kai NiuE3S Web Conf., 185 (2020) 01062DOI: https://doi.org/10.1051/e3sconf/202018501062