PMU simulation and application for power system stability monitoring

Wide area monitoring system consists of measuring the angle shift between the sub-networks using phasor measurement units (PMU). These new schemes are promising since a direct measurement of this quantity makes no assumption of the impedance of the tie-lines between the monitored sub-networks. Even if this technology is still at an early stage, a few pilot projects have been already initiated by major utilities over the world. Synchrophasor measurements are becoming one of the new features available in some multifunctional protection devices. There is an ongoing discussion in the industry regarding the integration into the line protection. At this time, since the actual requirements for such measurements is fairly limited and they are used predominantly by non-protection applications, many protection professionals express preference to keep such functions in stand alone or disturbance recording devices. On the other hand, there are new requirements for development of system integrity protection schemes (SIPS) that may need the integration of phasor measurements in the relays. It is anticipated that over the next five to ten years over 500 to 1,000 PMUs will be deployed world-wide. Each PMU typically monitors 6-8 phasor quantities, such as voltages, currents, and frequency, all of which are time-stamp synchronized using a Global Positioning System (GPS) satellite.