Cramér-Rao Lower Bound for Forced Oscillations under Independent Multi-channel PMU measurements in Power Systems

Abstract

Forced oscillations threaten the reliability of wide-area power systems, and different approaches to estimate forced oscillation have been explored over the past several years. Though these efforts provide powerful tools to estimate a forced oscillation's amplitude, frequency, and phase, a benchmark for estimation accuracy has not been available. This paper provides initial results in such a benchmark called the Cramér-Rao Lower Bound which is a lower bound on the variance in those estimates. A direct approach to derive Cramér-Rao Lower Bound of forced oscillation in power systems is given. In the end, the MinniWECC model is applied to assess the impact of different factors on the bound.