  Power electronic devices such as HVDC and FACTS can be used to improve the
damping of poorly damped inter-area modes in large power systems. This involves
the use of wide-area feedback signals, which are transmitted via communication
networks. The performance of the closed-loop system is strongly influenced by
the delay associated with wide-area signals. The random nature of this delay
introduces a switched linear system model. The stability assessment of such a
system requires linear matrix inequality based approaches. This makes the
stability analysis more complicated as the system size increases. To address
this challenge, this paper proposes a delay-processing strategy that simplifies
the modelling and analysis in discrete-domain. In contrast to the existing
stability assessment techniques, the proposed approach is advantageous because
the stability, as well as damping performance, can be accurately predicted by a
simplified analysis. The proposed methodology is verified with a case study on
the 2-area 4-machine power system with a series compensated tie-line. The
results are found to be in accordance with the predictions of the proposed
simplified analysis.
