New improvements in accurate measurement of synchronously sampled AC signals

approach to the design of digital algorithm based on use of dual-slope ADC is described in this paper. Based on this approach, a new technique for algorithm design is developed. The main advantage of this approach Is the determination of all electric values in electric utilities by the same algorithm. The algorithm has a high accuracy and regular structure. Measurements of voltage and current are made in successive periods by a stroboscopic technique (synchronous undersampling). The assumed stationary of the electric utilities is validated by measurements with an experimental setup, consisting of a fast high precision sigma-delta ADC [1]. The necessary synchronization is reached by software measurements of the frequeney of the measured signal. Assuming stationarity of the observed system (electric utilities) in the stated one-second interval, it is proved that precise digital processing can be achieved without using a sample-and-hold circuit. The suggested measuring system was simulated, practically realized and tested, and obtained results confirmed completely the starting postulates. Processing precision of 0.01% was achieved.