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Static energy meters have shown errors beyond the standards due to conducted electromagnetic interference of pulsed currents. This was observed in several case studies and confirmed by laboratory experiments, which showed errors up to 2675%. The extent of this interference case is unknown, because there is limited information about the waveforms occurring in the real on-site scenarios. This article aims to detect critical waveforms in on-site surveyed data that have similar characteristics as the pulses that resulted in metering errors. The time-domain parameters of the laboratory experiments that show static energy meter interference are compared to the on-site waveform data using an interpolation based on an inverse weighting distance function. Using this approach, the waveform characteristics are compared, and an error is estimated. This approach was satisfactorily validated using data from validation experiments that shows a correct estimation of the actual error according to the permissible limits for energy metering for all validation indices. The performed on-site surveys show the existence of nonlinear waveforms. During the survey of three sites for ten days, 19 531 waveforms were captured, of which 14 487 indicate large nonlinearities and 379 are estimated to produce metering errors up to 925%. [ABSTRACT FROM AUTHOR]

Measurement bandwidth of energy measurements are increasing to incorporate all the harmonics created by nonlinear loads and distributed generators making the measurement electronics complex and sensitive to electromagnetic interference. This article proposes to change the accuracy paradigm by focusing on fundamental active power and lower harmonics for energy metering, simplifying the electronics and making them robust against electromagnetic interference. Using the orthogonality of power flow via Parseval's theorem, a theoretical analysis, simulations, and measurements on power calculations using the fundamental active power are presented. It is shown that a perfect power measurement is achieved with a pure 50 Hz supply voltage, regardless of the nonlinear current. Even with the highest allowed harmonic distortion of the voltage and the current as listed in the international standards EN 50160 and IEC 61000-3-2, more than 97.5% of the active power is contained in the fundamental active power. Negligible active power is contained in the higher frequency components. This error margin falls within limits for electricity meters. Filtering the current with a basic low-pass filter can prevent the erroneous measurements that have appeared with static energy meters. In other words, it has been proven that negligible energy flows in the higher frequency components. [ABSTRACT FROM AUTHOR]