The Effects of the Smoothing of the Results on the Measurement Accuracy of RMS and Powers in Systems Under Nonsinusoidal Conditions

The effects of the smoothing of the results on the measurement accuracy of powers and RMS values in systems under nonsinusoidal conditions are considered. The presence of time measurement intervals of given rated duration is assumed. Suitable formulas to evaluate the errors introduced by the desynchronization of measurement interval for active power, and voltage and current rms values are developed. Then, the errors are evaluated in presence of smoothing of the results over a variable number of consecutive measurements by means of proper formulas, showing the improvements of accuracy that can be obtained. A numerical experiment based on experimental data concludes the analysis.