AC-constrained economic dispatch in radial power networks considering both continuous and discrete controllable devices

Economic dispatch (ED) is widely studied in power system optimization and is a typical application of optimal power flow (OFF). As more distributed generation resources integrated, e.g. micro-turbines and renewable generators, the AC-constrained ED (ACED) of distribution power networks (a typical radial power networks) is more controllable and the operation optimization of which is essentially a complicated Mixed Integer Nonconvex Nonlinear Programming (MLNNLP) problem with discrete controllable devices, e.g. transformers and compensating capacitors. In this paper, we studied ACED problem of radial power networks based on Branch Flow model. To make this problem tractable, the piecewise linear (PWE) and latest second-order cone (SOC) relaxation techniques are employed to relaxe ACED to a Mixed Integer Second-order Cone Programming (MISOCP) problem which can be efficiently solved by commercial solvers. Besides, we also discussed the exactness of SOC relaxation for ACED problem of radial power networks based on recent research achievements in this area. The modified IEEE 33 bus system is studied which validated the effectiveness and high computation efficiency of the proposed method.