Smart grid data integrity attacks: Observable islands

Unobservable data integrity attacks are coordinated cyber attacks on power meter readings that are undetectable by any bad data detection algorithm. Counter measures against data integrity attacks have been extensively studied in the context of observable islands; however, the concept of observable islands has only been introduced for a specific type of attack known as the power injection attack which compromises only power injection meters and power flow meters. This manuscript introduces the concept of observable islands to a recently identified type of data integrity attack that may also compromise breaker status meters. We call this type of attack a General Data Integrity attack (GDI attack). The results presented here allow for observable island based PMU placement countermeasures, initially developed for power injection attacks, to be applied to GDI attacks. An example shows that these observable islands are prominent when using both linear state estimators and non-linear state estimators.