In this paper the results of a study on automatic detection, identification and location of systemic disturbances are described. The signal used for detection is the frequency obtained by phasor measurement units installed at Universities (SPMS MedFasee BT). Problems associated with frequency behavior are discussed, and three filtering methods are used in order to generate signals suitable for signaling detection of disturbances. The disturbances are classified in transient, loss of generation and load interruption. The estimation of the events location is performed by triangulation using Newton's method. Actual events that occurred in the Brazilian Interconnected Power System are analyzed. The results show that SPMS allow the use of the described applications in real time operation.