Real-time power system monitoring at demand sides by Campus Wide Area Measurement System

Modern electric power transmission and distribution systems form a huge and complicated system. Fortunately, phasor measurement units (PMUs) have been developed, which can correct voltage phasors as sequential data with precise time synchronization based on time stamps by the Global Positioning System (GPS). The PMU has great possibilities for wide area measurement or protection in the power system. Recently, advanced information technologies make it available that any users, not only power system operators, perform the wide area measurement by the PMU. Authors and co-researchers have developed global monitoring systems of Japanese and Southeast Asian power systems by the PMUs, which are named as Campus Wide area measurement systems (campus WAMSs). This paper investigates the possibility of the Campus WAMS as a simple online monitoring system of power system dynamics. The monitoring system only plots the corrected data on a plane of frequency deviation versus phase difference, and evaluates an expanse of an aggregate of the data. Therefore, the monitoring system can be run even at the customer-side and reduce data processing and influences by loss of data or time synchronization. The availability of the monitoring system is confirmed by examples of the actual data.