In this paper, a computational low-demanding Model Predictive Control (MPC) strategy is proposed to deal with the transient stability control problem in Smart Grid systems. The proposed MPC controller is based on a dual model set-theoretic paradigm capable of robustly coping with model uncertainties and sensor measurement noise. Most of the required computations are moved into an offline phase leaving into the online phase a simple and computationally affordable convex optimization problem. A notable property of the proposed scheme is the capability of ensuring that transient stability is robustly achieved in a finite, and a priori known, time interval, regardless of any disturbance realization. The conducted simulation example shows the effectiveness of the proposed solution.