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

Modern mode meters can estimate modal properties from ambient data to monitor small signal stability of power systems; however, forced oscillations appearing in ambient data could affect the estimation process placing the resilience of wide-area power systems at risk. To eliminate mode meters bias caused by forced oscillations, accurate estimation of parameters of forced oscillations is one of the crucial steps. Cramér-Rao Lower Bound (CRLB) is not connected to a particular estimation method of forced oscillations, but CRLB provides insight into how well forced oscillation parameters can be estimated. This paper extends previous works to study how CRLBs alter under statistically independent two-channel PMU measurements. Although the case of independent multi-channel PMU measurements is rare in practice, it can provide a valuable reference in reviewing the case of correlated multi-channel PMU measurements.