State estimation for distribution systems using micro-synchrophasors

Phasor Measurement Unit (PMU) has contributed greatly to power system state estimation because of its ability to directly measure voltage and current phase angle. PMUs have been used almost exclusively in transmission systems monitoring. Recent years, increasing penetration of renewable energy sources brings new characteristics into distribution system such as bi-directional power flows and voltage profile issues, which has necessitated continuous monitoring of distribution systems. Therefore, fast and accurate measurement device is needed for application in distribution networks. μPMU is such a device that can provide phasor measurements with high precision and low cost. This paper uses a linear three phase state estimator for applications in distribution systems. The proposed estimator can make use of synchrophasor measurements which can be realized by μPMU. This is tested on IEEE 13 bus feeder which has unbalanced three phase transmission lines and loads.