Despite the overall consideration by the conventional optimal power flow (OPF) of the economy

safety and quality of power system

the OPF model is based only on the electric model to the neglect of the branch thermal model

which is a great deviation from the dispatch of an actual power system. On the basis of the theory of electric coordination and the relationship between resistance and temperature of the branch

a temperature-dependent OPF model with electro-thermal coupling is proposed. To further improve the efficiency of the algorithm

the electric model and thermal model are decoupled and then solved by the interior-point method. Finally

it is shown by the simulation results of IEEE 5-bus

Case 30-

2736-

and 3012-bus of MATPOWER and actual 1856-bus test systems that the proposed model and method are successful and correct. This work is supported by National Natural Science Foundation of China (No. 51107032

No. 51277052

No. 61104045).