A Study on State Estimation Using Hybrid Measurement Data

As the economy develops and power demand increases, the need for stable power system operation is also increasing. State estimation, one of the important functions of EMS(energy management system), estimates the state of the power system which is essential for reliable power system operation. State estimation has traditionally been performed using measurement data, obtained from SCADA(supervisory control acquisition system). PMU(phasor measurement unit), which appeared in the early 1990s, improved state estimation by providing more accurate synchronized data than SCADA measurement data. However, due to various problems, the PMU cannot be implemented at all buses in the power system, and for this problem, a study on a hybrid state estimation technique using both SCADA and PMU measurement data is required. This paper proposes a new technique for hybrid state estimation using SCADA and PMU measurement data. The proposed technique can improve the conventional state estimator and reduce the influence of bad data. Tests are done in the IEEE test system and the KEPCO power system.