SU1318949A1 - Method of calibration checking of voltage dividers - Google Patents

Abstract

This invention relates to electrical measuring technology. The purpose of the invention is to expand the functionality of the method. The output voltage of the alternating voltage source 1 is set to the nominal value. The phase and amplitude of the output voltage of the alternating voltage source 2 is changed to MOMeHta to achieve the equal potential of the outputs of the dividers 3 and 4 of the voltage. In this case, the zero-body will fix the equality of zero voltage between points B and C. In this case, the amplitudes and phases of the voltages on the high-voltage arms of dividers 3 and 4 are equal. 3 il. (L CAD 00so with Figure 1

Description

t

The invention relates to electrical measuring technology and can be used in the calibration of voltage dividers.

The purpose of the invention is to extend the functionality by determining the amplitude and angle errors of a rotatable divider when powered by alternating current.

Fig, 1 presents a diagram of the device that implements the proposed method; FIGS. 2 and 3 are vector diagrams of the voltages of this device and the errors of the verified divider, respectively;

: The device contains the main and auxiliary sources 1 and 2 of alternating voltage | the amplitude and phase adjustable, respectively, j exemplary and rotatable voltage dividers 3 and 4, a zero indicator 5 and a comparison unit 6. Moreover, the first terminals of the primary and auxiliary sources 1 and 2 of the alternating voltage are connected and connected to the first output of the voltage divider 4, the second view of which is connected to the first output of the exemplary voltage divider 3 and the second output of the main alternating voltage source, the second output alternating voltage source 2 — with a second output of an exemplary voltage divider 3; a null indicator 5 is connected to the middle points of the reference and tunable voltage amplifiers 3 and 4, and block 6 is tim - to first terminals of the main and auxiliary sources 1 and 2, an alternating voltage.

The output voltage V of the main source 1 of the alternating voltage is set to nominal. The output voltage V of the auxiliary source 2 of the alternating voltage varies in amplitude and phase until the potential of the outputs of the reference and calibrated dividers 3 and 4 of the voltage is reached. until the indicator indicator 5 indicates that the voltage between points B and C is equal to zero, and the amplitudes and phases of the voltages on the high-voltage arms of both dividers are equal to each other (V Vg),

Thus, the vector stress diagram takes the form shown in Fig. 2, where C is the angle

189492

between the voltage vector of the supply of the controlled divider 3 voltage Udd and the output voltage V of the auxiliary source 2 of the alternating voltage. The relative complex error of the voltage switch 4 to be tested is determined from the expression for the conversion coefficient of the turntable voltage divider 4, eg, 0 zhen:

to „to„ (1st) (О

where, К „- conversion factors

Vani respectively of the model and verified dividers of 3 and 4 voltages.

From where

20

Y 1, -% 2.

° K,

(2)

From the definition of the conversion factor, it follows:

K ,, v, / vj ,,; v ,, / v,

or

VBC VCA - K; (3)

Va6 V, - K „, (4)

where Vjjj,, Vgg - weekend voltages

model and verified dividers of 3 and 4 voltages;

V, Udd - input voltages

model and verified dividers of 3 and 4 voltages.

And 9 vector stress diagram

(FIG. 2) it follows that

VDA - V ,,;

VOB VOP.

(5) (6)

Substituting (5) in (3), (3) and (4) in (6), we get:

V –x K fV - V 1 X K + V

od - n oa ov-oo

Where, taking into account (1):

to:.

to

.V,

Oa

The expression for the relative complex error of the conversion coefficient of the calibrated divider at op313

is determined by the conversion factor of the model divider Cd and the ratio of the output voltages of the auxiliary 2 (Udr) and the main I (VQ) of the amplitude and phase of the voltage sources:

Have

-H.G-1

oa

Since tf, is the angle between the vectors Vo0 and WAD, the last extrusion can be represented as follows:

. to"

Yiu

Vo

X (cosif + ysinif),

Taking into account (2), the vector error diagram takes the form shown in Fig. 3, where y is the relative amplitude error of the conversion coefficient of the calibrated divider 4, Ji is the angular error of the conversion coefficient of the rotational divider 4, expressed in radians and the corresponding angular error 8 expressed in degrees.

Based on the vector error diagram and formula (7), the expressions for determining the relative amplitude

The error of the conversion factor of the calibrated voltage divider 4 and its angular error are:

X)

cos If; (eight)

. , krlVoB,

 arcsxn (- x x

Claims (1)

Invention Formula A voltage divider calibration method in which the potentials of the outputs of the model and calibrated dividers are equalized so that, in order to expand the functionality by determining the amplitude and angular error of the calibrated divider when supplied with AC voltage, the voltage is changed supply one of the dividers in amplitude and phase with equal potentials of their inputs, determine the difference of their supply voltages, compare with the input or output voltage of one of the dividers and the result judged on amplitude and angular error x .dover emogo divider. CP " 6 / FIG. g Editor B, Danko Compiled by 0, Safohin Tehred M. Khodanych Order 2506/39 Circulation 730 Subscription VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab ,, d, 4/5 Printing and production enterprise, Uzhgorod, Projecto st., 4 Fig.Z Proofreader L. Pilipenko