J. Pereira, O. Postolache, P. Girão, H. Ramos
MINIMISING ERRORS DUE TO NON-SIMULTANEOUS SAMPLING OF VOLTAGE AND CURRENT IN DIGITAL POWER MEASUREMENT SYSTEMS
A common solution to measure electrical power is through the use of systems that digitise voltage and current signals. However, several errors can affect the accuracy of such systems, namely transducer errors, sampling errors [1] and analogue-to-digital conversion errors. Sampling errors can be very important especially when low-cost solutions for digitalisation are considered. In this case, besides truncation errors caused by spectral leakage, non-simultaneous sampling of voltage and current signals, due to the absence of sample-and-hold-circuits, can also introduce large amplitude errors. In the present paper, an easy solution to minimise the last type of errors is proposed and some simulation and experiment results are presented to validate that solution.