Network observability: The critical measurement identification using the symbolic Jacobian matrix

This paper presents a new method for critical measurement identification. A measurement is said to be critical, in observability sense, if its removal from the measurement set leads the system to lose observability. The proposed method is based on the analysis of the measurement jacobian matrix structure as presented by Slutsker & Scudder [10] (for network observability purpose). It does allow to identify the critical measurements without any calculation or even solving algebraic equations. It does not have combinatory nature, being simple and fast. In order to clarify the methodology and show its simplicity, two numerical examples are provided. One to illustrates how the observability analysis works and the other to show how the proposed methodology identifies critical measurements. The proposed methodology is successfully tested in the system of 6-bus (Fig. 1), in the IEEE-14 bus system and in a 121-bus system from ELETROSUL [5].