To improve the operational economy of distribution networks with high penetration of renewable energy

this paper studies the AC–DC interconnected distribution networks with multiterminal soft open points (SOPs) and its optimal operation strategy. Firstly

the structure of the multiterminal AC–DC interconnected system and the operational characteristics of each component are analysed

which forms the constraints of the optimization model. Secondly

a multi-objective optimization model is established to achieve the optimal system operational economy

minimum network loss and maximum load balance rate of each distribution transformers at each port. Finally

aiming at the nonlinear operational characteristics such as the power flow constraints of the networks

a solution algorithm based on second-order cone convex optimization is designed. A case study based on the 5-terminal interconnected system demonstrates that on the premise of ensuring load power supply and system power flow constraints

the proposed method reduces the daily operation cost by 8.18% and cuts the total network loss by 3.52%.