POWER SYSTEM STATE ESTIMATION - IIT Mandi

(Cont.,)• When using the WLS estimation method, detection andidentification of bad data are done only after the estimationprocess by processing the measurement residuals.J x ( z h( x) )' W z h(x)• The condition of optimality is that the gradient of J(x) vanishesat the optimal solution x, i.e., 1GX H WZ 0 1 1X G H WZ• An estimate z of the measurement vector z is given byZHX• The vector of residuals is defined as e = z - Hx; an estimate ofe is given byez h(x)