Synchronization of phasor measurement units and its error propagation to state estimators

Abstract

The recent breakthrough on power grid technologies was promoted by the emergence of phasor measurement units (PMUs), as they provide direct and high-rate data for analyzing and controlling the network. Time becomes critical however, since offsets in the internal clocks of PMUs render their data unreliable. In this context, the present work describes grid-wide implementation of a Precision Time Protocol system to deliver an accurate time reference to PMUs at different power stations. Residual time offsets are modeled as PMU noise, propagating to linear state estimators, and their non-linear counterparts that result from combining PMU and power flow data.