Wide Area Situational Awareness Assessment Using Phasor Measurement Unit

Abstract

ABSTRACT newlineAs proclaimed by the American Academy of Engineering, the modern power industry turned out to be milestone-engineering achievement of the twentieth century, being the largest, most integrated machine built so far with a staggering number of interconnections. Furthermore, factors such as the diverse and distributed nature of power consumption and increased use of renewable sources of energy have exacerbated the complexity of the power grid. A failure in one part of this complex network, unless promptly detected, can translate into a major power outage. For real-time monitoring and control of the power system, the problem demands the application of a wide area measurement system (WAMS). Traditional supervisory control and data acquisition (SCADA) systems can measure the parameters at a maximum rate of one per second, mostly updated in every three to four seconds. The incorporation of renewable energy with the main grid is altering the basic operation of main grid by inducing fast dynamics that go unobserved using SCADA system. Synchrophasors are time-synchronized measurements that constantly stream out from devices known as phasor measurement units (PMUs) at a rate of 30 to 60 frames per second. These high-speed measurements provide actual and post-event visibility of the system dynamics. These time-synchronized measurements were feasible with accessibility of the global positioning system (GPS) and high-speed information processing methods. PMU technology offers a highly automated measurement system such that one can monitor the state of the system precisely to perform proper control actions and thereby minimize system damage. newlinePMUs are the edifice of a WAMS. They offer measurements of positive sequence voltages and currents, synchronized in one microsecond. At any specified instant, positive sequence measurements can access the state of the power system directly. Apart from positive sequence voltages and currents, PMUs also calculate local frequency and rate of change of frequency. Further, they can be ta