The power Angle and Phase Measurement Units based Wide Area Measurement System and its application

A new method for the measurement of the rotor angles and the phasors of power systems is proposed in this paper. Based on this method, the angle and phase measurement unit (APMU) has been developed. The rotor angles can be measured directly with speed signals of generators instead of being calculated with the power equations of the generator. Hence, the measurement precision of the rotor angle is improved. Based on the APMU and the Global Position System (GPS), a wide area measurement system (WAMS) has been constructed in the HeNan power grid (HNPG), China. The control center for the WAMS was also developed. The server in the control center collects the real-time data from all the APMUs, analyzes the operation state of the power network, records the dynamic responses of the power system under disturbances, and displays the information with the graphical user interface (GUI). The measurements were also applied in the detection of low frequency oscillation, on-line state estimation and parameter estimation of synchronous generators.