Phasor Measurement Units for the Distribution Grid: Necessity and Benefits

High penetration levels of distributed energy resources (DER) and active loads in the distribution grid can change the traditional grid from a slower-changing radial network to a multi-source network with faster dynamics. Although overall system reliability and quality of supply can in principle be improved under this paradigm, new control and protection challenges could arise that may not be adequately addressed using the traditional approaches. The conventional control and management of the distribution grid where only voltage magnitudes are measured and utilized at the control center could undermine these new dynamics and may potentially lead to severe complications in grid operation. A system-wide dynamic analysis and control of the distribution grid therefore seems crucial for optimal system operation. This would require new phasor data, coming from Phasor Measurement Units (PMU), to be incorporated into the functions of Distribution Management System (DMS). This paper discusses the potential applications within the DMS that can benefit from PMU data.