Identification of bad data and dynamic changes in network structure

In many cases network structure changes are the precursors of blackout, so it is very important to identify network structure changes on time for security analysis and to prevent blackout, especially where the structure change is accompanied by wrong status information and bad data. This paper presents a method of innovation graph to identify topology changes which occur at the same place of bad data. The method first identifies bad data correlated with network changes by the concept of bad loop. After bad data's effect is eliminated, structure changes can be identified correctly. Therefore it can provide useful information for security supervision and blackout prevention.