Estimation of the Effect of Non-Synchronization of Voltage and Current Samples on the Active Power Measurement Error

Abstract

To measure power parameters, two measurement channels are applied: voltage and current. For accurate measurement of active power parameters, the voltage and current samples must be synchronized in time. Each of the measurement channels contains ADCs, due to the imperfection of which there is a delay of the samples of one signal relative to another. This causes the active power error. Two components of this deviation can be distinguished: constant (aperture time) and variable (aperture jitter) in time. The paper considers the measurement error of active power parameters due to non-synchronization of current and voltage samples. Analytical error expressions are obtained from the aperture jitter and aperture time error components. The influence of signal parameters (amplitude values, initial phases, sampling frequency, measurement time, sample number, phase shift) on the active power error is considered. The case of aperture bounce representation by means of a random function with normal and uniform distribution density is considered. It is shown that for the case of a uniform distribution density, the active power error is higher.