The topology error identification is a puzzle in state estimation, new state variables representing breaker status are introduced in topology estimation, which is rigorous for demanding higher precision of measurements and makes it difficult for bad data identification. Practically, these methods are not suitable for being applied in EMS. A new fast topology estimation method without introducing any new state variables is proposed in state estimation. In this method, all branches (line or transformer winding) with uncertain status are equaled to energy consumers and are identified by verifying the measurement consistency of power flow and associated breaker status. The status of suspected branches could be ascertained from the power flow results of equivalent energy consumers. The criteria of ascertaining branch status are offered. Once the status of a branch is detected, its power flow can be calculated using bus voltages of both sides. After power injections of all buses are modified, the whole states of power system can be achieved without carrying out state estimation again. This method is also effective to light load branches topology errors. The performance of the proposed method is assessed through its application to one of province EMS, considering different types of topology errors and distinct network configurations.