Uncertainty management in the measurements for the electric power quality analysis

The paper deals with the uncertainty estimation in the measurements performed to assess the electric power quality. In a first steps, all the error sources, which give a significant contribution to the combined uncertainty associated to the measurement results, are identified. Successively, in order to analyze how the errors combine and propagate through the measurement chain, four approaches are proposed and validated. These approaches entail a greater and greater uncertainty overestimation, but, at the same time, require less and less time and resources. Therefore, the four methodologies are perfectly adequate for the implementation of the PUMA (Procedure for Uncertainty Management) method that is an iterative technique, originally conceived for geometrical and mechanical measurements. This practice allows to optimize the cost of the measurements versus the uncertainty target, avoiding the use of inadequate or, on the contrary, too expensive measurement instruments.