KEYNOTE SPEAKER

Phasor Measurements as Smart Device for Observing Power System Dynamics

Prof. Yasunori Mitani
Kyushu Institute of Technology, Japan

Abstract

Phasor Measurement Unit (PMU) is an apparatus which detects the absolute value of phase angle in sinusoidal signal. Here, suppose that more than two measurement units for instantaneous voltage with short sampling time are located distantly apart from each other. Then, we can get multiple measured voltage data but they cannot be compared exactly along with time since we do not know the reference of time. However, once they are used with GPS signal which tells us the information on exact time, it becomes ready to get phase differences among them. Thus, PMU with GPS receiver is applied to the monitoring of AC power system dynamics and usually installed at substations of transmission lines.
On the other hand, our group is developing the system with PMUs installed at user power outlet; 100V in Japan and 240 V in Thailand. In Japan we are developing a power system monitoring system with PMUs installed at University’s campuses, which is called Campus WAMS (wide area measurement system). As a result, we can monitor the wide area power system stability and dynamics viewed from user side. In addition, we have developed a signal processing method with an FFT filtering or a wavelet transformation to eliminate the noises of voltage around user power outlets and a method to identify an equivalent vibration model for the evaluation of power system stability with the processed signals. The PMU system provides us useful information on phasor voltage distributions on the power system map. From these data we can get the dynamic behaviors of power flows. In this context the PMU system is expected as a new device to support the smart grid.
This keynote speech presents some results on the power system observation in Japan and in South-East Asia (Singapore-Malaysia and Thailand).

Biography of the Keynote Speaker

Yasunori Mitani received the B.S., M.S., and D.Eng. Degrees in electrical engineering from Osaka University, Osaka, Japan, in 1981, 1983, and 1986, respectively. Currently he is a Professor in the Department of Electrical Engineering, Kyushu Institute of Technology, Fukuoka, Japan. He was a Visiting Research Associate at the University of California, Berkeley from 1994 to 1995. His research interests are in the areas of analysis and control of power systems.