SU1129526A1 - Electric power meter - Google Patents

Abstract

ELECTRIC ENERGY COUNTER containing a multiplier, the first input of which is connected to the first input bus, the second input - to the second input bus through a signal polarity switch, the control input of which is connected to the generator output and the control input of the reverse counter, the counting input of which is connected via a resistor to the output the multiplier, the first plate of the first capacitor, the output of the reference current source and the input of an inverting DC amplifier, the output of which through a pulse shaper is stable volt-second square is connected to the counting input of a reversible counter, characterized in that, in order to improve measurement accuracy, a second capacitor and an additional switch are inputted to it, the input of which is connected to the output of an inverter DC amplifier, the control input - to the generator output, the first output is with the second cover of the first capacitor, and the second output through the second capacitor 1C output of the multiplier.

Description

The invention relates to electrical measuring equipment and can be used to measure ac and dc electrical energy. Known electricity meter containing the multiplier with a pulse. the main output, the code of which is connected to the first input of the logic unit, the second input of which is connected to the output of the generator, and the output to the inputs of the reversible counter, the output of which is connected to the digital indicator fj. The known device is characterized by insufficient measurement accuracy due to additive errors of the multiplier. The closest to the invention to the technical essence is an electricity meter containing a multiplier, the first input of which is connected to the first input bus, the second input to the second input bus through a signal polarity switch, the KOTOpci o input connected to the generator output and the control input by reversing the reversing counter, the counting input of which is connected through a resistor to the multiplier output, the first capacitor plate, the output of the reference current source and the input of an inverting dc amplifier, the stroke of which is connected to the second capacitor plate and through the pulse shaper of a stable volt-second area with a counting input of the reversing counter 2j. However, the measurement accuracy of this device is also not high enough due to the fact that the residual charge of the capacitor accumulated in the flow. The previous half cycle of the device operation is taken into account in the next half cycle with the opposite required sign. The purpose of the invention is to improve the measurement accuracy. The goal is achieved by the fact that the electricity meter containing the multiplier, the first input of which is connected to the first input bus, the second input to the second input bus c, doesn’t switch the signal from the control input of which is connected to the output of the generator and input. control house for reversing reverse counter, the counting input of which is connected through a resistor to the multiplier output, the first field of the first capacitor, the output of the reference current source and the input of the inverter DC amplifier, the output of which is connected to a stable volt-second area through the pulse shaper of the stable volt-second area connected to the counting input reversible counter, a second capacitor and an additional switch are introduced, the input of which is connected to the output of an inverting DC amplifier, the control input - to the output of g generator, the first output - with the second plate of the first capacitor, and the second output through the second capacitor with the output multiply: tel. The drawing shows a functional diagram of the proposed electricity meter. The counter contains a switch 1 polarity of the signal, a multiplier 2, the first input of which is connected to the first input bus, the second input to the output of the switch 1 polarity of the signal, and the output - to the input of an inverting amplifier 3 DC, the output of the source 4 reference current of the first plate of the first capacitor 5, the first plate of the second capacitor 6 and the output of the pulse shaper 7 of a stable volt-second area through a resistor 8. The output of the amplifier 3 is connected to the input of the shaper 7 and the input of the additional switch 9, the first The output of which is connected to the second plate-capacitor 5, the second output to the second plate of the capacitor 6, and the control input to the control input of the switch 1, the output of the generator 10 and the control input of the reversible counter reversal 11. Additional switch 9 can be in one of the two states depending on the value of the signal at its control input. In the first state, its input and the first output are closed, the second input and the second output are closed. The output of the driver 7 is connected to the counting input of the reversible counter 11. The device operates in a very efficient manner. In the first half-period of operation of the generator 10, the input current indicator through the switch 1 of the polarity of the signal with a plus sign is supplied to the conveyor 2, to which it also supplies a voltage signal from the input signal. An additional switch 9 in this half-period connects the output of the amplifier 3 to the second plate of the capacitor 5, on which a voltage is formed (Je proportional to the integral of the sum of the currents coming from source 4 and multiplier 2) In the second half-period of the clock generator, the switch 1 of the signal changes This does not change the sign of the output signal of the multiplier 2. A voltage Ug proportional to the integral of the difference of the currents coming from source 4 and from the multiplier 2 code in this field The operation is formed on the capacitor 6, which is connected to the output of the amplifier 3 by the switch 9, ... When the voltage reaches One threshold value in the first half-period or the voltage U, the second driver triggers the voltage generator 7 and the voltage Ug or U decreases by the value determined feedback pulse parameters. The pulses from the output of the imaging unit 7 are fed to the counting: input of the reversible counter 11, the control input of which is reversed is connected to the output of the generator 10, and during the first half period of operation snip 11 operates at layer set, during a second - for subtraction. Next, the device repeats operation. The number of pulses at the output driver 7 in the first half period of operation is equal to t-fK, llVWHUH) 3t (g-H6. ". During the second period, this number is i |, + 2T K, j (Vk nUH ai Hfe -Ve current and voltage in the circuit to be measured-, Ki, K - coefficients proportional .f N - the number of pulses at the output of the driver 7; Q - the charge transmitted by each of these pulses QcjOr - the initial charge on the capacitors 5 and 6 ; ah, 5 is the residual charge on the capacitors 5 and 6j About the time of the beginning of the first period of operation of the generator 10; T is the duration of the half period of operation The generator 10. The measurement result is recorded as a change in the state of the reversible counter 11. Back the time of the full period of operation of the generator 10, the state of the reversible counter 11 is changed by the value (H5-15 U6-Ch6: Thus, for the full period of work, the result is measured proportional to the energy consumed in the measured target, and since the residual charges a and o are formed and stored on different capacitors 5 and 6, an increase in the measurement accuracy will occur over several periods of operation. Switching the signal ambiguity in conjunction with a change in the counting direction in a reversible counter eliminates the influence of additive errors of the meter nodes. Switching capacitors, synchronous with switching the polarity of the signal, results in a charge on the capacitor uncompensated by feedback pulses in the first half period .; the operation of the device is taken into account in the subsequent operation, and the accuracy of the measurement does not depend on the number of output pulses of the driver that fall into the half-cycle of switching the polarity of the signal.

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Claims (1)

The ELECTRIC POWER METER containing a multiplier, the first input of which is connected to the first input bus, the second input to the second input bus through the signal polarity switch, the control input of which is connected to the generator output and the reverse control input of the reversible counter, the counting input of which is connected through the resistor to the output of the multiplier, the first lining of the first capacitor, the output of the reference current source and the input of the inverting DC amplifier, the output of which is stable through the pulse former the second-second area is connected to the counting input of the reversible counter, characterized in that, in order to increase the measurement accuracy, a second capacitor and an additional switch are inserted into it, the input of which is connected to the output of the inverted DC amplifier, the control input is to the output of the generator , the first output - with the second cover of the first capacitor, and the second output through the second capacitor 1 with the output of the multiplier. SU ,,,, 1129526> 1 1129526 I