On the accuracy of state estimation

This paper illustrates a weakness of state estimation in regard of modeling errors. The Q-V model is in general much more complex than the P-delta model, and Q-V solutions can be badly affected by relatively small modeling errors even when its P-delta part is accurate. The paper analyses the impact of model inaccuracies and measurement bias on the solutions. Solution algorithms examined are least-squares, a modification of it called DWLS, and Huber