Distribution system state estimation using unsynchronized phasor measurements

Abstract

Accurate monitoring of the distribution system is performed using state estimation methods. The purpose of these methods is to estimate the most likely state of the grid given various types of redundant measurements. In this paper, we propose a three phase state estimation method that can handle accurately unsynchronized three phase phasor measurements. Unsynchronized phasor measurements, as opposed to synchrophasor measurements, consist in phasor measurements that do not have accurate time stamps. The use of such measurements could be very valuable in unbalanced distribution networks. To handle these measurements, we add unknown synchronizing operators to the state variables. The identification of these additional state variables allows considering any configuration of unsynchronized phasor measurement in a simple and intuitive way. The proposed method is illustrated on a simulated distribution network.