Security-constrained economic dispatch(SCED)is the key issue for achieving secure

economic and efficient operation of AC/DC Interconnected system. To this end

a new iterative SCED mode is proposed to coordinate the problem both in time and space dimension. An SCED model for AC/DC Interconnected system is established taking AC power flow equations

DC transmission system static operation functions

and time interval coupled constrains into consideration. To solve the problem of large-scale non-linear programming model

an efficient iterative algorithm is proposed based on Benders decomposition method. Case study is conducted to validate the effectiveness of the proposed mode

model and method in three aspects containing optimal benefit

convergence progress and computational efficiency. This work is supported by National Key Technologies R&D Program(No. 2013BAA01B02)and State Grid Corporation of China(No. 5229NX15002B).