Power systems can experience poorly damped oscillations tendency which may cause loss of synchronism and security constraints infringement. This may be caused by disturbances in power consumption, failures, and recently by the presence of delays in monitoring process. In consequence, control systems, which must deal with delayed signals in monitoring and control, need to be designed to avoid instability in the system. This paper presents the application of a proposed Sliding Prediction Block which feeds a Model Predictive Control (MPC) aiming to increase the damping of oscillations in a nonlinear model of the delayed single-machine infinite-bus system (SMIB), and in the two area test case of Kundur. The proposed scheme controls the mechanical power to track the power reference at the infinite bus, and in Kundur system the method acts over the excitation system in one of its machines. Also, the analyzed cases consider delayed signals feeding the control strategy. Results show that combining the Sliding Prediction Block with Model Predictive Control (MPC) face effectively the time-delay problem.