State Estimation for the Localization of Harmonic Sources in Electric Distribution Systems

Throughout the last years, with the liberalization of the energy market, the localization of the sources of power quality disturbances has become a nodal point for operators and customers. In the liberalized market, knowledge of the system status, along with the uncertainty affecting the estimated data, is required to operate management and control issues such as Energy dispatching and protection coordination. In distribution systems, too many measurement instruments would be needed to obtain a complete observation of the electric quantities. Thus, model-based state-estimation techniques can be implemented to exploit the few real-time measurements from the field and all the other available information to estimate the desired quantities. In this paper, a novel approach to the estimation of the harmonic sources by means of a Bayesian approach is proposed. The procedure also allows the “quality” of the obtained estimates to be assessed. The theoretical fundamentals of the method are discussed, and results relevant to a simple distribution network are presented.