On the Variability of Random Errors Distribution in PMUs: An Experimental Characterization

Recent developments in the field of synchronized measurements based on Phasor Measurement Units (PMUs) have paved the way for innovative applications in monitoring and control of modern power systems, often grounded in the digital twin paradigm. For such systems to function optimally, it is essential to understand the uncertainty models of the devices deployed in the field. This knowledge helps determine the final accuracy of the estimates produced by state-of-the-art monitoring applications. In this context, the objective of this study is to establish a robust foundation for describing the distribution of PMU random errors, by experimentally analyzing three commercial devices from the same manufacturer fed with signals produced in a controlled laboratory setting. The results show that the Gaussian model can always be obtained for magnitude errors. Although the assumption of normality for phase-angle errors does not always perfectly match the data, the modest disparities suggest that standard deviation still reflects error variability.