Damping controller input-signal loss effects on the wide-area stability of an interconnected power system

Most countries in different parts of the world are getting closer to electricity industry deregulation. Deregulation has induced increase in network power transfers thus resulting in more constraint on power system oscillations. Now in big interconnected networks, the scope is becoming larger and larger. For instance, to cope with inter-area oscillations, power controllers need a more global vision (when a remote input signal is used in a power system stabiliser to damp inter-area oscillations). But in the perspective of deregulation, the knowledge of distant signals will not be guaranteed any more. This paper explores the problem of remote input signal loss for a remote feedback controller (RFC) used to damp inter-area oscillations in power systems. The similarity of the machine responses in the two areas oscillating against each other is used. The RFC is designed to be robust and effective when presented with the loss of one or many input signals. This performance is accomplished through the inclusion of synchronised measurements (GPS) from several points in the power system. The proposed signal-loss solutions are verified via small-signal analysis and dynamic simulations on both a 4- and 29-machines test power system.