Linear Distribution System State Estimation by Hybrid Synchronized/Unsynchronized Measurements

This paper proposes a linear state estimation method for unbalanced distribution systems using available synchronized/unsynchronized measurements. The paper demonstrates that circuit properties can readily be taken advantage of to linearly express power measurements in terms of bus voltages and line currents. This results in a linear distribution system state estimation (LDSSE) process, which involves two stages. In stage one, the three-phase voltage phase angles are estimated using available measurements and network parameters. By formulating voltage/current phasors based on these phase angles, linear equations are developed that enable the estimation of voltage phasors. The linear nature of the proposed method significantly reduces the computation time while maintaining the solution's accuracy. The superiority of the proposed LDSSE method over existing methods is verified using extensive simulation studies conducted on different test feeders.