Studies on Relations between Frequency and Phase Difference in Power System based on Phasor Measurements

M. Hojo and T. Ohnishi (Japan)


Global positioning system, time synchronization, phase measurement, power generation control, interconnected power systems


In power system analysis, most of researchers used to face a difficulty of measurement to study a large scale power system. Fortunately, precise time synchronization among different remote locations can be realized by time stamps of the Global Positioning System (GPS) in recent years. By the time synchronization and information technology, it becomes available to execute practical analysis based on synchronized measurements of large power system. Authors have constructed an online global monitoring system of the Western Japan 60Hz power system. In our previous studies, frequency variation characteristics of the power system can be observed by the monitoring system. This paper mainly discusses system characteristics by investigating the measured data on a plane of frequency deviation versus phase difference. The plots on the plane show the stiffness and controlled behaviours of the power system. From these analyses, it is confirmed that the multiple synchronized phasor measurement system has a great possibility to investigate the global power system in an easy way.

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