Soft open points（SOPs） have the ability to regulate the power flow among their terminals in a continuous manner

which can solve the problems brought by the synergy of distribution networks and DGs

and improve the system reliability and power supply capability. To address the current lack of quantitative measurement on the effects of SOPs

the power supply capability evaluation method for active distribution networks with four-terminal SOPs considering reliability is proposed. Firstly

the topology and configuration modes of four-terminal SOPs are investigated

and the control modes of them are investigated in normal operation and supply recovery conditions. Then

by using the feeder partition method

the effects of four-terminal SOPs on the power outage time of different load areas after a fault are studied

the FMEA model and the post-fault load shedding and transfer model of the active distribution networks with four-terminal SOPs are established

and the reliability evaluation process is developed. Thirdly

with reliability as the main constraint

the power supply capability evaluation model for active distribution networks with four-terminal SOPs is established

and the solution algorithm is proposed. Finally

the effectiveness and applicability of the method proposed are verified through case study.