There is an increasing awareness of resilience for active distribution networks (ADNs) as extreme fault conditions pose threats to the reliable operation of power supply. Islanding operation of ADNs with distributed generators (DGs) and energy storage system (ESS) can significantly serve the critical electricity demands and improve the power supply reliability. Considering the characteristics of DG, ESS and load, a time-series islanding partition model of ADNs is established based on soft open point (SOP). The proposed model exploits the benefits of operational flexibility provided by SOP to improve the level of load recovery. It further takes into account the coordination of the control strategies among regulation devices as well as the failure duration in island partition, while satisfying a variety of operational constraints. Specifically, a mixed-integer nonlinear programming (MINLP) is employed to solve the proposed model effectively. Finally, case studies on IEEE 33-node and IEEE 123-node test feeders verify the effectiveness of the proposed method. (C) 2018 Elsevier Ltd. All rights reserved.