Smith predictor based backstepping control for damping power system oscillations

When a power system is exposed to a major disturbance, the system exhibits a tendency towards poorly damped oscillations which may cause loss of synchronism; in consequence, control actions, which must deal with the presence of delays in monitoring and control signals, have to be performed to avoid an instability in the system. This paper presents the application of a nonlinear control strategy for the damping of oscillations in a delayed single-machine infinite-bus system. The damping of oscillations is achieved by acting over the mechanical power and tracking the electrical power reference at the infinite bus. Also, it is addressed the issue of time-delayed signals considering the electrical power at the infinite bus as a delayed remote signal. Results show that the proposed Smith predictor based backstepping control effectively resolves the time-delay problem, and its possible application to multi machine systems is promising.