Adaptive sampling scheme for monitoring oscillations using Prony analysis

Monitoring generator oscillations using Prony analysis is an application that is being increasingly implemented using phasor measurement units (PMUs) data. Most of the existing literature for power system oscillations using Prony method report implementing fixed sampling window that is obtained following a systematic iterative approach taking into account potential disturbances. The fixed sampling technique, although simple to implement, does not optimise the data acquisition time. Moreover, sampling using inadequate intervals can potentially lead to errors during Prony analysis. In this study mathematical formulations are derived to show the effect of small and large sampling intervals. Further, a technique using condition number is proposed as a quality index for signalling the errors arising because of the choice of sampling interval. To facilitate an efficient monitoring rate, while still maintaining sufficient accuracy, an adaptive sampling scheme is proposed. This study demonstrates that the proposed scheme can potentially exhibit faster monitoring rate with acceptable accuracy during practical implementation.