In the original formulation of the AEP estimator, only measurements of complex power flows in transmission lines and transformers were processed and a reference voltage measurement was used deterministically (1). This meas- urement set permitted the formulation of a relatively simple and computationally fast algorithm. This paper discusses the formulation for including voltage and injection measurements in the present algorithm. One important aspect of the paper is the expansion of the measurement set while preserving the basic char- acteristics of the original algorithm. The paper also discusses the detection and identification of erroneous measurements as well as the calculation of confidence limits from the expanded measurement set.