Empirical Evaluation of GPS Clock Accuracy for Isochronous Droop-based Inverters

Conference · Tue Nov 16 04:00:00 EST 2021

DOI:https://doi.org/10.1109/ECCE47101.2021.9595448· OSTI ID:1844359

Meyers, Toby; Mather, Barry

Grid-forming inverters rely upon an internal reference to regulate the grid 's voltage and frequency. Without a reliable reference, issues such as loss of synchronism, frequency instability, and unequal power sharing can occur. One proposed internal phase reference for grid-forming inverters is generated by the controller's clock, but this is affected by nonidealities in the crystal oscillator leading to time drift in the phase reference. To improve the controller's clock accuracy, the Global Positioning System (GPS) can be used to calibrate the internal clock. Previously, GPS-based clock calibration was explored theoretically and various methods were developed for mitigating frequency/phase drift at the power system level. This paper experimentally validates the direct performance of GPS time-calibration at the controller level and justifies its use in maintaining an accurate phase reference for droop-based grid-forming inverters.

• Research Organization: National Renewable Energy Laboratory (NREL), Golden, CO (United States)
• Sponsoring Organization: USDOE National Renewable Energy Laboratory (NREL), Laboratory Directed Research and Development (LDRD) Program
• DOE Contract Number: AC36-08GO28308
• OSTI ID: 1844359
• Report Number(s): NREL/CP-5D00-82055; MainId:82828; UUID:7cb56f76-d990-444d-bcf1-0da5be63ceea; MainAdminID:63820
• Country of Publication: United States
• Language: English

Related Subjects

GPS
POWER TRANSMISSION AND DISTRIBUTION
clock drift
decentralize
droop
grid forming inverter
power sharing
stability
synchronization