Optimal Computation of the Transmission System Expansion Planning using the Branch and Bound Method

A new method for transmission line expansion planning using the branch and bound method is presented in this paper. Some candidate alternatives should be chosen in the beginning of planning procedures. To obtain the economical optimal scheme, all of these candidate alternatives should be considered, so this paper gave a concept of the planning set for describing all elements such as the transmission lines expanded or modified in the alternatives. The optimum planning was computed by the branch and bound methods which is very effective in solving the mixed optimization problem, and the relaxations of sub-problems were solved by interior point method which is a mature method solving continuous optimization problem. The planning algorithm presented in this paper was applied to IEEE39 bus testing system. The simulation results testify the validity of the proposed method.