Researchers from Federal University of Pará suggested the development of a three-phase state estimation algorithm
Power system operators conventionally use state estimator programs to remotely monitor electrical transmission systems in real time. Time is spent carefully monitoring the system conditions in order to anticipate and mitigate potentially dangerous and costly system problems. These programs aid in verifying the compliance of network voltages with national regulatory agency requirements. These transmission systems can estimate process such as redundant sets of measurements, meshed-grid topology, balanced operations, and fully-automated grids. These programs are included in the Supervisory Control and Data Acquisition (SCADA) software that offers calculation data and topological information that aids in efficient performance of state estimator.
However, grids of electrical distribution systems present unbalanced operation, a very limited number of measurements, poorly-automated electrical grids, and radial topology. This in turn can decrease calculation redundancy, thereby offering high errors of estimation. Now, a team of researchers from Federal University of Pará suggested a method to estimate the state variables of electric distribution systems. The new approach is based on three-phase version of the weighted least squares (WLS) conventional state estimation method. According to the researchers, the new method can assess the electric distribution system operation state.
The new approach creates pseudo-measurements along the whole distribution feeder to increase the measurement redundancy of distribution networks. Obtaining a reasonable trade-off between the number of measurements required by the state estimator and the size of the observable area within the distribution grid is a challenging task as such grid needs a substantial amount of measurements for the estimator to work properly. The new approach generates pseudo-measurements throughout the distribution grid to address this issue, thereby offering a full-observable network. The team found that the proposed approach can effectively estimate the distribution grid operation state. Moreover, the approach performs well to obtain estimates of the operation state that are accurate for practical applications. The method also offers the estimates of commercial losses and billed energy for any operating points. The research was published in the journal MDPI Energies on April 06, 2019.