Series compensation using variable structure and Lyapunov function controls for stabilization multimachine power system

This paper invests in the potentiality of transmission capability flexibilization of power system to improve the margin of stability system. Series compensation is introduced to change the transmission line reactance by means of controlled switching strategy. This switching attends the concepts of variable structure control to carry the system on stabilization sliding mode where the oscillations are attenuate quickly. A switching strategy can be created to guarantee the existence of this sliding mode. Another strategy, based in Lyapunov direct method, will guarantee the asymptotic stability inside the region. A third strategy, combine both earlier, will permit to reach more quickly the sliding surface in stability region. In addition, it is applied the control Lyapunov functions to specific verification, using the concepts of negative derivative of this function for asymptotic stability of electric system. A power system consisting of two electric subsystems interconnected by a line reactance with series compensation is used as a case study. The integrated control strategy is applied in this power system and assures a fast converge towards a stable equilibrium state.