DIGITAL POWER METER Russian patent published in 2014 - IPC G01R21/06 

FIELD: electricity.

SUBSTANCE: invention is related to electric engineering and may be used in different devices of electric power systems. The digital power meter includes an electric receiver and a binary counter, which counting input is coupled to conjunctor output coupled to by its first input to the generator output controlled by voltage and the reset input is coupled to output of the synchronisation pulse generator coupled by its inputs to the input terminals of the mains. In order to reach technical result the current-to-voltage converter is introduced and coupled by input terminals between the second terminal of the mains and the second clamp of the electric receiver, the first comparator is coupled by its subtracting input to sawtooth voltage output of the generator and by its summing input to the output of the current-to-voltage converter and by output to the second input of the conjunctor, and the second and third comparators are coupled by its summing inputs respectively to the output of the current-to-voltage converter and to the first terminal of the mains and by its subtracting inputs to the second terminal of the mains and by its outputs to inputs of the logic equivalency circuit, which output is coupled to the third input of the conjunctor, as well there is an additional binary counter, the logic equivalency circuit and an additional conjunctor, which output is connected to the counting input of the additional binary counter, the first input is coupled to output of the first comparator, the second input is coupled to output of the generator controlled by voltage and the third input is coupled to the logic equivalency circuit, at that the reset input of the additional binary counter is coupled to output of the synchronising pulse generator.

EFFECT: reduction of measurement error in circuits with reactive power.

2 cl, 3 dwg