Load modeling for distribution circuit state estimation

Due to the limited availability of telemetered data on distribution circuits, an integral part of any practical distribution circuit state estimator is a load modeling procedure that provides estimates of load demands at all circuit nodes. Traditional load modeling techniques used for distribution power flows are designed for power system peak studies, and are not suitable for providing real-time statistical load estimates. This paper presents a real-time load modeling technique which incorporates the use of customer class curves and provides a measure of the uncertainty (statistics) in the estimates. It also incorporates the possibility of multiple line flow measurements and makes use of customer billing information. The load modeling technique is combined with a probabilistic distribution circuit state estimation algorithm. Results of the combined load modeling and state estimation algorithm are provided on an actual 934-bus distribution circuit illustrating its feasibility.