In this article, the
primal-dual interior-point methods are used to minimize costs and losses in a
predispatch model for the generation and transmission of direct current (DC)
power flow in a hydroelectric system with pre-programmed manipulations; i.e., in cases of preventive
maintenance, within a period of twenty-four hours. From the computational
standpoint, the effort required to solve a problem with and without
manipulations is similar, and the reasons why will be also discussed in this
study. Computational results prove these findings.