An Overview of State Estimation Based on Wide-area Measurement System

The gradual development of the wide-area measurement system (WAMS) in China presents an opportunity to improve the on-line analysis methods of power system. Given such advantages of the WAMS as higher metering quality, possessing synchronized phasor measurements and fast data communications, the status quo on power system state estimation based on WAMS is reviewed and analyzed from three aspects, including the models of using nodal voltage phasor measurements with high accuracy, models of using branch current phasor measurements with high accuracy and models of using all phasor measurements. This paper studies all these models in detail, comments on their advantages and disadvantages, gives some suggestion, and discusses the feasibility and application range from the point of view of the engineering application. Furthermore, other problems relating to the estimators based on WAMS are also discussed, such as the bad data detection and identification, the phasor measurement unit (PMU) optimal placement and dynamic state estimation and harmonic state estimation based on PMUs.