Preliminary Sensitivity Analysis of Combinatorial Optimization (CO) for NILM Applications: Effect of the Meter Accuracy

Non-Intrusive Load Monitoring (NILM) techniques are today of great interest for several applications contexts. Indeed, the possibility of exploiting these techniques for having energy consumption data in a unique aggregated metric is very attractive not only for the cost-saving (due to the installation of a reduced number of meters) but also for catching important information coming from the field and addressed to implement predictive maintenance paradigms on the devices of interest. As matter of fact, the continued analysis (by means of the NILM techniques) of each load behavior could enable in detecting of dangerous situations or also identify incoming slow faults occurring on the loads themselves. Although the NILM techniques have been deeply analyzed in the scientific literature, some lacks are related to the analysis of the impact of the measurement uncertainty on their performance as well as to the capability of correctly identifying the loads operating against the number of loads present. In this framework, this paper proposes a preliminary sensitivity analysis aimed at verifying the impact of the meters measurement uncertainty and the number of loads involved on the performance of a well-known NILM technique, i.e. the Combinatorial Optimization (CO). To this aim, several measurement accuracies, power metrics, and the number of loads have been taken into account. The achieved results prove how the considered quantities of influence generally affect the performance of CO and can also provide useful information to the designers of the measurement system as an example in defining the best feature to be used, the maximum measurement uncertainty for a given number of loads, able to warrant the target accuracy required by the specific application.