A practical modeling of circuit breakers with unknown statuses in generalized state estimators

This paper proposes a new practical approach for including circuit breakers with unknown statuses in the formulation of the generalized state estimation problem. Unlike other proposals, only one single operating constraint is proposed for representing two possible and mutually exclusive breaker statuses: closed or open. This is achieved by using the concept of complementarity conditions based on the apparent power flow and complex voltages across the breaker terminals. This complementarity constraint is then transformed into an equality constraint by using the Fischer-Burmeister merit function, and it is directly included into the state estimation problem to simultaneously co-estimate the operating state of the entire network together with the breaker’s unknown operating statuses. The proposal’s effectiveness is demonstrated in the IEEE 24-bus benchmark system with different substation configurations and circuit breakers with unknown statuses.