Optimal power flow of two-terminal HVDC systems using backtracking search algorithm

•OPF of two-terminal HVDC systems is solved by using backtracking search algorithm (BSA).•BSA is a population based evolutionary algorithm (EA).•The proposed method is tested on three different IEEE test systems.•The results by BSA are compared with those by ABC algorithm, GA, and the numerical method.•The production costs and CPU times by BSA are less than those by the other methods.