Empirical determination of voltage phasor angle deviation threshold for synchrophasor-based substation topology estimation

Current methods of topology estimation rely on breaker statuses to obtain accurate results. However, due to the lack of availability of time stamped breaker status data in many electric systems, as well as the errors associated with this data, these methods are very limited in their current scope. Additionally, synchrophasor measurements can be used to supplement information on the connectivity between two nodes. The state of a breaker is correlated to the vector difference between the voltage phasors on either side of the breaker. The methodology presented in this paper calculates a voltage angle deviation threshold to determine topology inside a substation. The algorithm calculates the voltage phasor deviations for each possible set of breaker configurations. The threshold is then determined, such that the threshold is correct for a statistically significant portion of cases, while remaining a realistic value considering the Total Vector Error among the voltage phasor measurements.