This paper presents a fast method for multiple measurement placement for sy
stems that are found to be unobservable. Upon placement of multiple measure
ments, all observable islands will be merged together and the entire system
will be rendered fully observable. The method uses a test matrix whose lea
ding dimension is determined by the rank deficiency of the gain matrix. The
refore, even for very large systems, as long as the number of measurements
to be placed Is relatively low, proposed method will maintain its computati
onal advantage. Compared to the existing iterative approaches, this method
directly provides the entire set of additional measurements for placement.
The method is developed based on authors' previous work [4] where a direct
method for observability analysis was presented.