Real-Time Synchrophasor Estimation in PV-Rich Grids Via Distributed D-PMU Design

This paper presents a wide-bandwidth distributed phasor measurement unit (D-PMU) system tailored for photovoltaic-rich distribution networks. The proposed system integrates a heterogeneous FPGA-ARM hardware platform and a GPS-disciplined adaptive recursive DFT (A-RDFT) algorithm for real-time and high-precision synchrophasor estimation. Phasor data are streamed at 100 frames per second via the IEEE C37.118.2 protocol, achieving microsecond-level synchronization and millisecond-level latency. Field deployment at a PV station demonstrates the system’s capability to accurately track frequency, voltage magnitude, and phase angle variations. A 10-min test shows the frequency error remains within 0.2 mHz and the total vector error (TVE) within 0.05, both well below IEEE Std C37.118.1 limits. The D-PMU also successfully captures dynamic events such as inverter switching and cloud-induced power fluctuations. These results confirm the system’s suitability for deployment in converter-dominated grids and its effectiveness in supporting advanced applications such as oscillation early warning, inverter disturbance localization, and grid stability enhancement. The proposed solution provides a practical and scalable pathway for enhancing situational awareness in next-generation smart distribution networks.