Integrating synchrophasors and oscillography for wide-area power system analysis

The Hawaii Electric Light Company has successfully implemented an automated system to collect synchrophasor and intelligent electronic device (IED) oscillographic reports. They are realizing the benefits of analyzing these two data types together. This paper shares power system disturbances from their system. It also discusses the advantages of integrating time-stamped synchrophasor and IED oscillographic reports together in one power system analysis application. Modern IEDs provide high-accuracy, time-stamped power system measurements primarily in two formats—streaming synchrophasors and high-sample-rate oscillographic reports. Although historically these measurement classes have been treated separately, modern technology is bringing them together and enabling new applications. Synchrophasor measurements are a growing part of real-time operations at utilities during power system disturbances. They provide operators and engineers with a window into the present operating condition of the power grid that is not visible with the typical supervisory control and data acquisition (SCADA) measurement rates. Traditional post-disturbance analysis involves analyzing high- sample-rate oscillographic reports in order to understand the specific details of a disturbance and the IED operation during the disturbance. The advent of synchrophasors has driven the deployment of global timing signals to IEDs. Because of this, oscillographic reports are now time-stamped with the same high- precision timing source as synchrophasors. Combining synchrophasor measurements and IED oscillographic reports during post-disturbance analysis provides a wide-area context for a better understanding of the conditions leading up to and following a disturbance. Furthermore, integrating the collection of time-aligned IED oscillographic report summaries results in a system that automatically collects and displays these reports along with the synchrophasor data. These oscillographic report summaries can help further characterize the detected disturbance by providing IED information, fault location, fault current, and faulted phases to power system operations personnel.