A Review on Active Distribution System State Estimation

State estimation is crucial in the development of adequate network models for power system monitoring and analysis. It is the computing of the nearest estimation of the nodal voltage magnitude and phasor angle using measurements populated from the power system. Since its inception in the 1970s Power System State Estimation (PSSE) has been extensively researched and applied in power transmission systems. However, monitoring of the voltage magnitudes and line power flow beyond the distribution substations is only a recent phenomenon, hence distribution state estimation is still uncommon. The need for Distribution System State Estimation (DSSE) is important since modern power systems comprise of distributed generation (DG) in consumer networks, that is; active distribution networks. This paper reviews early work in PSSE and DSSE. Bad data detection and identification, network observability analysis, meter placement and future research work directions are discussed.