Improving network parameter error detection via multiple measurement scans

It was previously shown that normalized Lagrange multipliers in state estimation could be effectively used for network parameter error detection and identification. However, it was also observed that there could exist a number of 'insensitive' normalized Lagrange multipliers corresponding to certain parameters which might lead to detection failure. This paper derives the relationship between Lagrange multipliers and parameter errors and explains the reasons behind detection failures. Furthermore, it facilitates the identification of insensitive normalized Lagrange multipliers. These results are then used to clarify the significance of incorporating multiple measurement scans as a way of avoiding detection failure and to derive a new approach for estimating the necessary number of scans to guarantee parameter error detection. Simulation results using the IEEE 14-bus system are presented to verify the proposed solution.