GPS signal loss in the wide area monitoring system: Prevalence, impact, and solution

- Investigation of the prevalence of GPS signal loss in the wide area monitoring system using a large amount of historical PMU data.
- Impact study of GPS signal loss on phasor measurement accuracy via experiments.
- Potential solutions to mitigate the impact of GPS signal loss on phasor measurement units.

The phasor measurement unit (PMUs), equipped with Global Positioning System (GPS) receivers for precise time synchronization, provides measurements of voltage and current phasors at different nodes of the wide area monitoring system. However, GPS receivers are likely to lose satellite signals due to various unpredictable factors. The prevalence of GPS signal loss (GSL) on PMUs is first investigated using real PMU data. The historical GSL events are extracted from a phasor data concentrator (PDC) and FNET/GridEye server. The correlation between GSL and time, spatial location, solar activity are explored via comprehensive statistical analysis. Furthermore, the impact of GSL on phasor measurement accuracy has been studied via experiments. Finally, several potential solutions to mitigate the impact of GSL on PMUs are discussed and compared.