Optimized grid reduction for state estimation algorithms in under-determined distribution grids

Abstract:
This paper describes a grid reduction algorithm that is able to reduce a grid model in order to run a state estimation for an under-determined distribution grid. For this purpose, an optimization was developed, which enables an optimized grid reduction based on different operating points. This optimization aims to reduce the grid ideally by selecting a suitable replacement node without influencing the state of the remaining grid. The replacement node is supposed to represent the aggregated nodes. The difference between the power flows into the unobservable grid area for the reduced and unreduced grid has to be minimized. Early results show that the placement of the replacement node is performing as desired. The grid reduction algorithm is embedded in a comprehensive tool for a complete analysis and preparation of grid areas for topology-based algorithms. Based on this grid reduction algorithm, an adaptive approach is planned, which selects the most optimal one depending on the operating point.