Design and Validation of a Very Low-Power Phasor Measurement Unit for the Distribution System

Phasor measurement units (PMUs) provide a high-resolution view of the power system at the locations where they are placed. As such, it is desirable to place them in bulk in low-voltage distribution circuits. However, the power consumption of a PMU/micro-PMU is on the order of Watts (W), requiring an external power supply, which both increases the overall cost as well as limits the locations where they can be placed. This work details the hardware design of a PMU capable of measuring and reporting voltage and current phasors for a single-phase system at an average power consumption of only 30.8 mW—one to two orders of magnitude lower than existing academic and commercial PMUs. This enables the proposed PMU to run for two weeks using an 11-Wh battery or indefinitely if paired with an inexpensive solar panel. A test bench developed in accordance with the 2018 IEC/IEEE 60255-118-1 PMU Standard confirms the accuracy of this PMU, and a Fluke 6135A PMU calibration system evaluates its performance under realistic conditions. Given its low power consumption, the proposed design is expected to accelerate adoption of PMUs in modern distribution grids.