The Dynamic Utilization of Substation Measurements to Maintain Power System Observability

In a power system state estimator (SE), a network topology processor (NTP) determines the circuit breaker (CB) status in real-time to obtain electrical network topology. In a conventional NTP, many substation measurements are simply discarded because their positions in the simplified bus-branch network model are lost. These measurements cannot be used in the network observability analysis and when some of the used measurements are lost, an estimate of system states may not be obtained. This paper proposes an innovative method to utilize these redundant measurements. The new method uses a numerical matrix to represent the physical connectivity of substation devices, and then dynamically searches for solutions to calculate branch and bus injection power flow measurement data using the linear combination of the available substation measurement data. Test cases on IEEE-30 bus system verify that the proposed method is very effective in making the network observable, without the need to install new measurement devices