OICC Press Majlesi Journal of Electrical Engineering 2345-3796 12 4 2024 02 15 Evaluation of Active Power Cost in Combined AC-DC Systems EN Vahid Talavat Department of Electrical and Computer Engineering of Urmia University, Urmia, Iran Sadjad Galvani Department of Power Engineering, Faculty of Electrical and Computer Engineering, Urmia University, Iran. Mahdi Hajibeigy Department of Electrical and Computer Engineering of Urmia University, Urmia, Iran Journal Article 2024 02 15 In this paper, the economic dispatch problem in combined AC-DC systems is studied based on the equivalent losses matrix of power flow. The proposed method is started by the calculation of the power flow for combined AC-DC system, then the calculation of the losses matrix. Afterwards, the economic dispatch problem is calculated by interior point method. The active powers which are founded by the economic dispatch problem, are used to recalculate the new power flow. The procedure will be iterated until the results convergence. Finally, several simulations are carried out on 14-bus system including five generation units, with and without DC links.