Abstract
Phasor measurement units (PMUs) have revolutionized power systems monitoring and control. By providing higher resolution measurements which provides better situational awareness, those time-synchronized measurements have enabled the development of better controls and operations for power systems. This paper discusses the basics of PMUs and their applications, mainly state estimation. The paper also presents a Kalman filter approach for state estimation. The NE 39 bus system is used under different circumstances to show the accuracy and robustness of the Kalman filter approach.