SU748634A1 - Voltage relay - Google Patents

Description

The invention relates to relay technology and is designed to protect consumers of alternating current from exceeding a predetermined level of effective voltage. Voltage relays are known, applied are protection of consumers of alternating current from overvoltage b-1, which contain a rectifier unit, a comparison unit, a zero-organ. connected to the comparison unit and the executive body. Of the known devices, the most comprehensive are the technical essence and the achieved result to the proposed 5shpas voltage relay | containing a two half-period rectifier connected to the protected network, an integrated circuit consisting of a series-connected capacitor and a resistor, a voltage comparison unit, a zero organ, and an actuator connected to it. The disadvantage of the known relay is that it possesses noise immunity in case of short-term emissions, the network caps, the length of which is much smaller than the amplitude of the voltage variation, however, it works with sufficient precision only in the case of С1scheusoidal voltage, and with a non-uniform voltage, the error is triggered. uvpicheaii.1. degree of n & sine wave. The circuit of the invention is to increase the accuracy of the operation of a rave. It is achieved by the fact that in a turnip a voltage containing a full-wave rectifier connected to an eashac & network, integrating uenoitka, cocTosirayso from a successively connected capacitor and resistor, compare unit, zero-o | and an actuator connected to it, the voltage comparison unit is designed as a non-linear bridge, the two arms of which are a potentiometer connected in parallel to an integrating circuit capacitor connected to two other Displayed dvuk popuperiodnogo rectifier. The other two / shoulders of the non-linear bridge are pv3 V

748634

Eystore and Stabilization Reinht Chr LgSHYy 1st 1st P1Ns and RVDi point of potential gauge TGbSHena (To the Hynfr-Brgaya code, the ratio of Nsminat Analogue resistor of the integrating circuit and the total ohmic, Gyroma, Gyroma, IQT, IQA, IQA, I, I, I, I and I, I, I, I, I, I, I will deal with the main the capacitor of the integrating chain is 1; 2.10

Such an implementation of the scheme allowed, with a ratio of resistance, resistor of the integrating chain and resistance of the nonlinear bridge equal to 1.: 2, to obtain the capacitor charge current-voltage characteristic in the integrating chain in a form close to a parabola, the maximum values of the voltage on the capacitor being proportional the total value of the charge transferred to the capacitor 20 by the end of the charge, and since the current value of the charge transferred to the capacitor depends on the magnitude of the charge current at this moment, and the charge The drive current varies approximately in a parabolic junction 25, b TO; The maximum value of the voltage across the capacitor will be proportional to the rms voltage, i.e., its effective value. In addition, in the scheme, the comparison of voltages at the level of nssc commensurate with the level of the monitored voltage, and ia the result of this POVEMgene accuracy of the control voltage, is given.

FIG. 1 shows an electric 35

 Cjcetvta is a voltage relay containing a full-wave rectifier 1, a resistor 2 and an integrator circuit capacitor 3 connected to the output diagonal of a two-period rectifier, a 40- volt meter 4, connected in parallel to the capacitor 3 and constituting the two arms of the non-linear bridge of the comparator unit, resistor 5 and op-amps and optic capacitor 3 the zener diode 6, the components of the two other arms of the non-linear bridge 45, the zero-body 7 and the executive body 8.

The scheme works as follows. The voltage of the monitored network is fed to the input diagonal of the two-half-so-one rectifier 1, and from the output diagonally ET01CHE bctrEy; Sha &Sha; Distributed voltage on the voltage measuring unit. .

From the beginning of the first half-period, through resistor 2, the capacitor 3 starts to charge es and continues to charge until the voltage on the falling branch of the half-wire equals the voltage of capacitor 3, after which the voltage applied to the measuring unit continues to drop to zero , and the capacitor 3 is mounted on a non-linear bridge, consisting of a potentiometer 4, a resistor 5 and a tablitron 6, with a speed determined by the parameter and circuit elements.

The dependence of the instantaneous value of the capacitor charge current on the absolute value of the alternating voltage U ;, at the input of the measuring unit will be:

.. U l-Uco

- R,

where J vieLnpsriKeviKe on cumulative

With.

the condenser by the time of the beginning of the charge during the subsequent period -,

The nominal value of the resistance of the resistor in the capacitor charge circuit.

Depending; you can, with a certain approximation, be replaced by a parabola, for which:

K a

The plot of this relationship is shown in FIG. 2

Due to the fact that after the end of each half-period the capacitor is discharged by a certain resistance of the non-linear bridge, by the beginning of the next half-period the capacitor 3 is not completely discharged, and therefore the charge in the next half-period does not start immediately, but after the voltage of the leading half-period reaches the value of the voltage on the con-g Densator 3.

In this case, in proportion to the voltage across the capacitor, the DC will also change the voltage ip, at the midpoint of the meter 4, which is compared to the reference voltage i, at the zener diode. If the voltage and "at the midpoint of the potentiometer exceeds the level of the reference voltage, the signal

(input voltage of zero-organ)

input-n-o to the input of the zero-body, which produces a command to the executive body.

The selection of the parameters of the elements of the measuring unit is made on the basis of the conditions for obtaining the volt-ampere characteristic of the capacitor charge, which is approximating in a parabola, and on the condition of comparing higher voltages. The process of separation on the load, in a unit of comparison, of voltages, the maximum values of which are proportional to the effective value of the resulting controlled voltage curve, is shown in the graphs of FIG. 3 (a, b, c). Thus, introducing a nonlinear bridge unit into the device, comparing 51, included as a load of the storage capacitor of the integrating chain, allowed to create a voltage relay reacting to the effective voltage of the monitored network, thereby improving the accuracy of the voltage relay operation. containing a full-wave rectifier connected to the protected network, integrating a chain consisting of a series-connected capacitor and a resistor, the unit is compared nor, the zero-organ and the executive organ connected to it, which is characterized by the fact that, with a circuit for improving the accuracy of the relay, the voltage comparison unit is made in the form of a non-linear bridge, the two arms of which are a potentiometer connected in parallel to an integrating circuit capacitor connected two different terminals of a full-wave rectifier, the other two arms of a non-linear bridge are a resistor and a zener diode, the junction point of which and the middle point of the potentiometer are connected to the inputs of the null organ, while the ratio of the nominal resistance value of the resistor and the integrating circuit in common ohmic input of the nonlinear bridge diagonal, is included as a load in parallel with capacitor integrating circuit ravnb 1: 2. Sources of information taken into account in the examination 1, USSR Author's Certificate No. 530369, cn. H 01 H 83 / 1O, 1976. 2. French Patent No. 2243542, cl. H 02 H 3/20, 1974. 3, USSR Copyright Certificate No. 233055, cl. H 01 H 47/32, 1967 (prototype).

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Claims (1)

The claims A voltage relay containing a two-20 half-period rectifier connected to the protected network, an integrating chain consisting of a capacitor and a resistor connected in series, a comparison unit, a zero-organ and an executive organ connected to it ^{25, which is} connected with the goal of the load, parallel to the capacitor of the integrating circuit, is 1: 2.