Inspec keywords: power system state estimation; nonlinear equations; vectors; matrix decomposition; covariance matrices; Kalman filters

Other keywords: square-root-extended complex Kalman filter; nonlinear state equation; state variables; ECKF; three-phase voltages; observation equation; complex vector; abc phases; convergence rate; three-phase instantaneous voltages; covariance matrix decomposition; αβ transformation; negative symmetrical components; positive symmetrical component; traditional extended complex Kalman filter; filter stability; complex number; αβ axes

Subjects: Mathematical analysis; Filtering methods in signal processing; Other topics in statistics; Algebra; Power systems