Grid state identification of distribution grids

The behavior and utilization of the electric power system is strongly influenced by the divergent interests of different market participants, particularly in the distribution level. To find a convenient grid operation strategy, decentralized energy management systems are applied. Knowledge of the grid state is essential for these management systems to work. For historical reasons measurement facilities are sparsely spread in distribution grids. Thus, grid states are not uniquely determinable solely by measured values but have to be estimated using on the one hand supplementary predicted values and on the other hand intelligent methods to infer on probable grid states. In this work different methods of state identification of underdetermined distribution grids are developed. They vary in the use of available information, the objective and the way, the grid state is determined.