SU1420541A2 - Device for measuring voltages in three-phase current - Google Patents

Abstract

The invention relates to a pulse technique and can be used to measure the amplitudes of a voltage and a three-phase circuit. The purpose of the invention — extending functionality — is achieved by providing static voltage control. The device contains a synchronization unit, an element OR 2, a counter 3, a decoder 4, a voltage converter 5 - a code, an analog switch 6, a driver 7, a clock frequency generator, a block 9 control 1, a reversible counter 10, a register 11, input 12 Start and an input 13 Installation zero. The number recorded in the meter will be proportional to the time during which the voltage at least in one phase does not meet the requirements of GOST. The proposed technical solution allows statistical control of the power supply. 3 Il.

Description

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The invention relates to a pulse technique and is intended to measure voltage amplitudes in a three-phase circuit.

The purpose of the invention is to enhance the functionality by allowing statistical stress control. ; Figures 1-3 show a block diagram of a device for measuring voltage in a three-phase circuit.

A device for measuring voltage in a three-phase circuit contains a synchronization unit 1, an OR 2 element, a counter 3, a decoder 4, a voltage converter 5. A code (ADC), an analog switch 6, a driver 7, a clock frequency generator 8, a control block 9, reversible counter 10, P gistr-11,. Input 12 Start and input 13 set zero, the input 12 start is connected to the first input of unit 1 synchronized, the second phase of the three-phase circuit is connected to the second input, the second output of the decoder 4 is connected to the second input , and to the output - the second input of the element OR 2, the output of which It is connected to the counting input of the counter 3, the output of which is connected to the input of the decoder 4, the first output of which is connected to the second input of the control unit 9, and the second to the control input of the analog switch 6, to the information inputs of which the phase voltages U are connected, U, Uj and to the output - the information input of the A / D converter 5 and the input of the imaging unit 7, the control output of the A / D converter 5 being connected to the first input of the OR element 2, the output of the imaging unit 7 is connected to the third input of the control unit 9, the fourth input of which is connected to the generator output 8 clock Frequency, and the input to the input - input 13 of the first zero output, control unit 9 is connected to the installation inputs of synchronization unit 1, counter 3, reversible counter 10 and register 11, the second output is connected to the control input of register 11, the third and fourth - outputs with inputs of summation and subtraction of the reversible counter 10, the Loan output of which is connected to the control input of the A / D converter 5, the first input of the control unit 9 and the zero input of the reversible counter 10, and the information output of the reversible counter 10 is connected to infor

Q

0 5 Q 0 5

five

0

the register input 11 and the output of register 11 with the information input of the reversible counter 10, the first group of inputs of the comparison unit 14 being connected to the information outputs of the A / D converter 5, and the second group of inputs to the output: m of the voltage level setting unit 15, the switch 16 is connected to the second output of the decoder 4, and the second input is connected to the output of the measurement of the ADC 5, and the third, fourth and fifth inputs are connected to the first, second and third outputs of the reference unit 14, the outputs are connected to the inputs of the time meter block 17 and display locale 18, the outputs of which are connected to the inputs of the additional element OR 19, the output of which is connected to the first input of the AND element, the second input connected to the first input of the synchronization unit 1, and the output connected to the input of the counter 21,

Comparison unit 14 contains elements 22 and 23 of comparing binary numbers, inputs connected to the inputs of comparison unit 14, and outputs - to the inputs of element And 24,

The switch 16 consists of a delay element 25 and switching blocks 26-28, including each three AND 29-31 elements.

The time meter unit 17 comprises time meters 32, including a serially connected counter 33, a decoder 34, and an indicator 35,

The display unit 18 forms the display elements 36-38, each of which includes three elements 39-41, an element 42 and indicator lamps 43-45. Positions 46 through 56 are indicated for the alignment of the bonds in Figures 1-3,.

The device works as follows.

Start-up pulses are received at Start 12 input (for example, at one minute intervals),

After measuring the voltage in the first phase, the binary code from the information outputs of the voltage converter 5 is compared in the comparison block 14 with the positional binary codes of the upper (a) and lower (b) voltage tolerances supplied from the block 15, setting the voltage levels wives If the measured voltage is higher than top 1

then there is a single

its level, the output level of the comparison element 22, i.e. on the first output of the comparison unit 14. If the measured voltage is below the lower acceptable level, then a single level appears at the output of the comparison element 23, i.e. at the third output of the comparison unit 14. If the voltage is normal, then at the outputs of the comparison elements 22, 23 there are zero levels and output element And 24 with inverse inputs, i.e. at the second output of the comparator unit 14, a single level appears. The position code from the second output of the decoder 4 is fed to the first input of the switch 16. As a result, a single level is fed to the second inputs of the AND 29-31 elements of the switching unit 26.

The impulse coming from the A / D converter 5 to the second input of the switch 16 is delayed by the response time of the comparison unit 14 on the delay element 25 and then simultaneously applied to all inputs of the AND elements of the switching blocks 26-28. The third inputs of the elements AND of these units are supplied with signals from the comparison unit 14. As a result, a pulse is generated at the output of one of the elements, for example, if the voltage was measured in the first phase and it turned out to be normal, then a pulse is formed at the output of the element 30. And the pulse from the output of the switch 16 goes to the input of the corresponding counter block 17 time measurements. The meter reading is highlighted on the corresponding indicator 35. When the device is started at one minute intervals, the meters show that the voltage is normal, above and below the norm for each phase in, minutes

After the measurements are completed, the measurement time period T set by the indicators of the time meter block 17 determines the probability Pj, with which the voltage disconnect value for the 1st phase is within acceptable limits using the formula:

R;

1 to p; + K t;

Where

K - the price of the output pulse

block counters 17 time meters, min / pulse

0

five

0

five

0

five

0

five

0

five

P; - the contents of the counter of the i-th phase of the voltage is below normal;

m j - the contents of the counter of the i-th phase of the voltage above the norm,

and further checks are made according to its standards GOST 13109-67.

In addition, the pulse from the output of the switch 16 goes to one of the inputs of the display unit 18 and then one of the D-inputs of the triggers and through the element 42 to the synchronous input of the flip-flops 39-41. As a result, one of the triggers turns out to be in state 1. and the other two - in O. The indicator light connected to the trigger located in the indicator is lit. single state. As a result, an indication of the quality of the voltage at a given point in time — above the norm, norm, below the norm.

When a signal appears above or below the norm on at least one ID, the element 19 is triggered and the signal from its output opens the key on the AND 20 element. As a result, the 51M pulse from input 12. The launch goes to the summing input of counter 21 released to the consumer during the measurement of T.

Therefore, the number recorded in the meter will be proportional to the time during which the voltage at least in one phase does not meet the requirements of GOST.

Thus, the proposed technical solution allows static control of voltage deviations in each phase.

Claims (1)

Invention Formula A device for measuring voltages in a three-phase circuit according to the author. No. 1287024, characterized in that, in order to expand the functionality by providing static voltage monitoring, a voltage level setting unit, a switch, a time meter unit, an indication unit, an additional OR element, an AND element, a counter and a comparison unit are introduced into it , the first group of inputs of which is connected to the information inputs of the voltage converter is a code, and the second group of inputs is connected to the outputs of the block for setting voltage levels, the first input of the switch is connected to the second Odom decoder ,. the second input is connected to the output. The end of the voltage metering code, and the third, fourth and five inputs are connected respectively to the first, second and third outputs of the comparison unit, the outputs are connected respectively to the inputs of the time meter unit and the display unit, whose outputs are connected to the inputs of an additional OR element connected to the first input of the AND element, the second input connected to the first input of the synchronization unit, and you With a meter connected to the input of the meter.  45 52 53 Ze W