Filter-based algorithm for metering apps

High accuracy metering is an essential feature of an electronic power meter application. Metering accuracy is a most important attribute because inaccurate metering can result in substantial amounts of lost revenue. Moreover, inaccurate metering can also undesirably result in overcharging to customers. The common sources of metering inaccuracies, or error sources in a meter, include the sensor devices, the sensor conditioning circuitry, the Analogue Front-End (AFE), and the metering algorithm executed either in a digital processing engine or a microcontroller. The critical task for a digital processing engine or a microcontroller in a metering application is accurate computation of active energy, reactive energy, active power, reactive power, apparent power, RMS voltage, and RMS current. The active and reactive energies are sometimes referred to as billing quantities. Their computations must be compliant with the EN50470-1 and EN50470-3 European standards for electronic meters of active energy class B and C, and IEC 62053-21 and IEC 62052-11 international standards for electronic meters of active energy classes 2 and 1, and the IEC 62053-23 international standard for static meters of reactive energy classes 2 and 3. The remaining quantities are calculated for informative purposes and they are referred as non-billing.

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Originally published by Freescale Semiconductor at www.freescale.com as "Filter-Based Algorithm for Metering Applications".