Oscillation monitoring system based on wide area synchrophasors in power systems

Abstract

With the growing implementation of synchrophasors or PMU's across the power grid, it is now possible to observe and analyze system wide dynamic phenomena in real-time. This paper presents the framework of an automatic real-time oscillation monitoring expert system for extracting the modal information and mode shape of electromagnetic oscillations while they are still emerging in the real power system. The algorithms use three signal processing engines, namely, Prony's method, matrix pencil method and Hankel total least squares (HTLS) method. Results from these engines are processed using a custom developed set of rules for handling the complexities of modal analysis from real-time PMU measurements. The results are illustrated on several actual PMU recordings from power systems in North America. A simple powerful control design is also explored to initiate a supplementary HVDC modulation scheme to damp out inter-area oscillations when the oscillation monitoring system detects poorly damped oscillations.