RU94040064A - Method for measuring electric power in two-wire supply lines which protects against tamper and device for implementation of said method - Google Patents

Abstract

FIELD: electric instruments which account use of alternating current. SUBSTANCE: method involves generation of signals of instantaneous values of power of current in phase and zero lines, calculation of average value, calculation of absolute value of difference between their average values, conversion of load power signal to frequency of pulse signal, and counting number of pulses. Novel feature of method is calculation of absolute value of sum of average of instantaneous values of power of current in phase and zero lines, adding it to absolute value of difference between them in order to calculate load level. Another claim of invention describes method which adds preliminary detection of difference and sum of currents in phase and zero lines. Said values are used for detection of differential and total instantaneous power values. Absolute values of their average values are used as constituents of load level signal. Yet another claim differs from previous one and describes method which is used for calculation of load power as average of sum of differential and total instantaneous power values which are sign-inverted. Sign inversion of each signal is used depending on polarity of their average value. EFFECT: correct measuring of load when electric power is tampered. 7 cl, 5 dwg, 1 tbl

Claims (1)

The invention relates to electrical engineering and can be used to measure electrical energy in AC circuits for commercial metering. The proposed method and device (their variants) make it possible to correctly measure the energy consumed by using various theft methods. The method involves the formation of signals of instantaneous power currents of the phase and zero wires, their subsequent averaging, determining the modulus of the difference between their average values, converting the load power signal to the frequency of the pulse signal and counting the number of pulses. New in the first variant of the method is the formation of the module of the sum of the averaged values of the instantaneous power currents of the phase and zero wires, its summation with the module of the difference of the averaged values of the instantaneous power currents of the phase and zero wires to obtain a load power signal. The difference between the second variant of the method is the preliminary determination of the difference and the sum of the currents of the phase and zero wires, which are used to determine the difference and total instantaneous powers. Modules of their average values are used as components of the load power signal. In the third variant of the method, in contrast to the second, the load power signal is generated as the average value of the sum of the difference and total instantaneous powers, which are previously subjected to sign inversion. Sign inversion of each signal is carried out depending on the polarity of their average value. 6 s.p. and 1 z.p. f-ly, 5 ill.