Analysis of time delay effects for wide-area damping control design using dominant path signals

The purpose of this article is to investigate the effects of time delays for wide-area damping control design when signals from dominant inter-area oscillation paths are used as feedback inputs for damping controllers. The analysis is carried out using a two-area study system. Frequency and time-domain responses of a generator's terminal voltage when the PSS uses PMU signals subject to time delays will be compared and assessed. The analysis reveals that while modal observability of the dominant path signals corresponds to the gain of the open-loop system at the inter-area frequency, these properties are inversely proportional to their corresponding delay margins.