SU437018A1 - Watt-hour meter - Google Patents

Description

one

The invention relates to electrical engineering.

From the main. av St. No. 286062 known watt-hour meter, made on the basis of the integral converter of electrical power in the number of pulses.

The purpose of the invention is to provide separate metering of energy consumption and energy recovery and increase the noise immunity of the output block of the meter.

To do this, it is equipped with a diode rectifying bridge, the input of which is connected to the output of a pulse-width modulator of the current conversion unit, and the output of the bridge is connected to the control input of a switch of a discrete-analog integrator, and a sign determining unit combined with an output unit .v keys, e.g., the base of each transistor, connected to the output of a pulse-width modulator through the resistor, and the emitters connected to the positive pole of the power source, the base-emitter transitions of each transistor to The switches are shunded by diodes in the opposite direction, a circuit consisting of a diode, a pulse counter winding and a storage capacitor connected to the negative zero of the power supply is connected to the collector circuit of each transistor. The circuit of the winding of the counter of pulses and the storage capacitor is shunted by a thyristor, the control electrode of which is connected via a diode-resistor chain to the output winding of a pulse transformer of a discrete-analog integrator, and the windings of pulse counters are shunted by diodes.

To extend the functionality for an amp-hour counter option, a voltage input of a discrete-analog integrator is connected to a stable voltage source.

The drawing shows the principal electrical circuit of the proposed meter.

The meter is supplemented with a separate metering device for consumption of electricity and recovery. The current input by shunt 1 to a given nominal load current contains a differential pulse-width modulator (PWM) 2 with a cycle of partial non-magnetization of the cores with a rectangular hysteresis loop. From collector windings (read windings) 3 through diodes 4 on resistors 5, positive readout pulses of rectangular shape are produced, the duration of which is proportional to (7op + / in / 2) and (I / on-

in / 2) on the left and right modulators, respectively (where J / on is the reference voltage level of the input bridge device; t / ux is the signal from the shield, proportional to the current of the shunt). The difference pulse, taken at points A and B, has a duration equal to the difference

the pulse durations of the left and right modulators, and the sign of the pulse is determined by the direction of the current through Schuit 1. The duration of the differential pulse is therefore proportional to the input signal, i.e. the shunt current

- hi

vy - counter aut. St. No. 286062 use only pulses of one polarity, since the key of the discrete-analog integrator used in the circuit of the counter is controlled by unipolar pulses.

In the present invention, the same integrator is used, and for its normal operation in the forward and reverse direction of the current in shunt 1, the output of the switch 6 key is connected to the output of the pulse-width modulator 2 via a rectifying bridge on the diodes 7. For separate metering of power consumption in the forward and reverse directions, a key circuit is used on transistors 8 and 9, each of which produces a key charge of its own storage capacitance. To simplify the base circuitry, both the key transistors are connected by emitters, and the n-p base-emitter junction of each transistor is diode-bridged in the opposite direction. Thus, with the forward direction of the current through the shunt 1, the polarity of the output PWM pulses 2 is indicated in the diagram and the transistor 8 is periodically turned on, while the transistor 9 is locked by a voltage drop on the shunt base-emitter junction diode. When this occurs, a stepwise exponential charge of the storage capacitance A of the left block of the thyristor reading device occurs. Zar d. Accumulative capacitance / 4 to the full voltage of the power source occurs before the output pulse arrives from the discrete-analog integrator 6. This pulse includes both the thyristor 10 and 11, but only the counter in the circuit of which there is a fully charged accumulator capacity. For the forward direction of the current in the charged left capacitance (according to the scheme), the meter 12 is taken into account for direct power consumption. When changing the direction of the current in the shunt, the polarity of the output pulses from the PWM output changes and now periodically for the pulse time

the right transistor switch 9 is turned on. This leads to a stepwise charge of the right storage capacitor B until the full voltage of the power source. At the moment of arrival of the pulse from the output of the integrator 6, the reverse flow pattern is triggered, and the pulse counter 13 — the indicator of reverse power consumption increases its readings by a unit of the received scale of the power integral.

Subject invention

Claims (2)

1. Watt-hour meter on auth. St. No. 286062, characterized in that in order to provide separate metering and energy recovery and increase the noise immunity of the output counter block, it is equipped with a rectifying diode bridge whose input is connected to the output of a pulse width modulator of the current conversion unit and the bridge output is connected to the control input key of discrete-analog integrator, and a sign determining unit combined with an output block containing two keys, for example, transistors, the bases of which are connected to the output of a pulse-width through a resistor snogo modulator, and emitters connected to the positive pole of the power source, the base-emitter junction of each transistor key shunted by diodes in the reverse direction in the collector circuit of each transistor included circuit consisting of a diode, the counter of the winding pulses and a storage capacitor connected to the negative pole of the power supply, the circuit of the pulse counter winding – accumulative capacitor is shunted by a thyristor, the control electrode of which is connected via a diode resistor to the output winding of a pulse transformer of a discrete analogue integrator, while the coils of pulse counters are shunted by diodes. 2. The counter according to claim 1, characterized in that, in order to extend the functionality for use as an ampere-hour counter, a voltage input of a discrete-analog integrator is connected to source of stable voltage. l z T