Mixed Measurements State Estimation Based on Wide-Area Measurement System and Analysis

This paper presents a new state estimation method in rectangular coordinates to solve the problem of lacking data redundancy of Wide-Area Measurement/Monitoring System (WAMS). This method utilizes all the measurements of WAMS and partial equivalent current phasor measurements transformed by flow measurements from SCADA system. The iterative formula is proposed and analyzed based on these mixed measurements. The theoretical analysis and tests show this method has constant Jacobian and gain matrices, and the gain matrix is decoupled as to deal with the real vector and imaginary vector of node voltage phasors. This method has fast convergence and is robust with different R/X ratios. Furthermore, the convergence character of this method is analyzed and tested in the case study. The treatment of power injections at buses is also discussed in this paper.