Monitoring power system dynamics based on phasor measurements from demand side outlets developed in Japan Western 60 Hz System

Japan Western 60 Hz System consists of six major electric power companies. Due to its longitudinal structure there are some significant oscillation modes represented by long term oscillation among whole system. So far, some oscillative characteristics have been measured in own area or in the interconnected tie lines. However, there was little observation as a whole power system. In this paper the authors present a global monitoring system of power system dynamics by using the synchronized phasor measurement of demand side outlets, which are located in some universities in the 60 Hz power system. Phasor measurements are synchronized based on the global positioning system (GPS) and measured data are transmitted via Internet. Some oscillative features and variation of phasor in a day, a week or a year are analyzed using the acquired data.