Estimation of uncertainty in measurement of power quality characteristics with a virtual measurement instrument

The paper deals with modeling and estimation of uncertainty in measurement of power quality (PQ) characteristics by using a virtual measurement instrument. The described virtual PQ analyzer is comprised of National Instruments (NI) analog input modules, NI data acquisition board, personal computer and software in LabVIEW™. The main sources of uncertainty are identified and evaluated. A Monte Carlo simulation is used for the model estimation and generation of the combined uncertainty of particular characteristics. Experimental measurement and statistical analysis of the results are made and compared with the simulation results. The experimental results have served for a verification of the model and the Monte Carlo simulation results.