Using current-magnitude measurements in decoupled state estimation

In this paper, a new fast-decoupled algorithm is presented to handle the current magnitude (CM) measurements. This method is based on the equivalent-current-measurements (ECM) in rectangular coordinates. Both the power and CM measurement are converted into the ECM form. The method produces a constant symmetric gain matrix, which can be decoupled into two identical sub-gain matrices. It is very efficient because one sub-gain matrix is used and needs to be factorized only once. The weighted least square (WLS) approach is employed to solve this problem. Tests have shown that the proposed method could outperform other formulations and have a great potential for online operations.