Measurement Placement Method for Improving Phase Estimation Accuracy in Distribution Network

This paper proposes a method for the joint-optimized placement of Feeder Terminal Units (FTUs) and Phasor Measurement Units (PMUs) in the distribution network. Firstly, the theory of observation zone division is introduced, and the impact of the number of unmeasured nodes within the observation zone on the accuracy of state estimation is analyzed. To address this issue, a measurement optimization placement model based on virtual flow is proposed, which is initially applied to FTU placement. The obtained placement locations are then used as reference positions for PMU optimization placement. Subsequently, improving the phase estimation accuracy of nodes on both sides of the tie switches is established as the principle for PMU placement. The objective is to minimize the distance between the interconnection nodes and the nearest PMU. An optimization problem is solved again to obtain the PMU placement scheme. Finally, taking the IEEE-33 node system as an example, the maximum number of unmeasured nodes within the observation zone and the relationship between the distance from the interconnection nodes to the nearest PMU and the number of measurement devices deployed are analyzed. This analysis helps determine the final measurement placement scheme for the system.