AbstractThe determination of the power components under non‐sinusoidal conditions has received great attention in the last years. Digital instrumentation, provided of signal processing capability, allows to accomplish this task by evaluating the voltage and current spectral characteristics, from which all the needed power components can be derived. The paper presents a parametric method, based on a proper model for the input signal, able to perform the evaluation of the spectral components on the basis of data collected during short observation interval. This characteristic enhances the tracking capability of the estimation method and is useful when time‐varying conditions must be detected.