SU813279A1 - Device for mains voltage fluctuation monitoring - Google Patents

Description

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The invention relates to electrical measuring equipment and can be used to control the quality of a mains voltage.

A device containing threshold elements, counters, logic elements, differentiator and driver 1 is known.

It is also known a device containing a reference value sensor, the output of which is connected to the first input of the logometer, the output of which is connected, is connected to the input of the indicator G2.

However, these devices are characterized by low accuracy.

The purpose of the invention is to improve accuracy.

The goal is achieved by the fact that a control unit, driver, multiplier, key, angular digital converter, two reversible counters, two code transfer blocks , minimum block, maximum block, the driver input is connected to the input signal bus and with: the first input of the analog-digital converter, the second input of which is connected to the output of the key, the input of which is multiplied The driver is connected to the output of the generator and to the input of the control unit, the first output of which is connected to the control input of the key, the second and third outputs of the control unit are connected respectively to the control output 1 of the first and

0 of the second code transfer unit, the outputs of which are connected to the corresponding inputs of the first reversible counter, the output of which is connected to the second input of the logometer, the third input

5 of which is connected to the output of the second reversible counter, the first input of which is connected to the output of the reference value sensor, and the second input to the output of the analog-to-digital converter and through the maximum unit to the input of the first code transfer unit, the input of the second code transfer unit is connected through the minimum unit with an analog-to-digital converter.

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The drawing shows a block diagram of a device for monitoring voltage deviations of a network.

The network voltage deviation monitoring device contains a reference value sensor 1 0, a logometer 2, an instructor 3, a control unit 4, a driver 5, a multiplier 6, a key 7, analog to Digital converter 8, reversible counters 9 and 10, code transfer units 11 and 12 , block 13 of the minimum, block 14 of the maximum. Moreover, the output of the sensor 1 is connected to the first input of the logometer 2, the output of which is connected to the input of the indicator 3, the input of the driver 5 is connected to the input signal bus 15 and the first input of the analog-digital converter 8 whose second input is connected to the output of the key 7, which input through the multiplier 6 connected to the output of the imaging unit 5 and to the input of the control unit 4, the first output of which is connected to the control input of the key 7, the second and third outputs of the control unit 4 are connected respectively to the control outputs of the first and second blocks 11 and 1 2 code transfers, the outputs of which are connected to the corresponding inputs of the reversible counter 10, the output of which is connected to the second input of the logometer 2, the third input of which is connected to the output of the reversing counter 9, the first input of which is connected to the output of the sensor 1, and the second input - to the output of the converter the caller 8 and through block 14 of the maximum with the input of block 12 of code transfer, the input of block 11 of code transfer through block 13 of the minimum is connected to the output of analog-digital converter 8. the device operates in three modes: device self-control, measurement from loneny voltage measurement -eg voltage fluctuations. The mode of self-control arrangement. The test voltage V Mc pushes to the inputs of the imaging unit 5 and the transducer 8. The imaging unit 1 generates pulses when the signal under study passes through zero values, which are fed to the multiplier 6 and the control unit 4. The control unit opens the key 7 for the time of one period Td of the signal under study. During this time, from the output of the multiplier 6 to the input of the converter 8, the switch 7 passes n pulses (rd n is the multiplier of the multiplier). These pulses trigger converter 8 at times -i. Instantaneous voltage codes of the nominal signal from the converter output go to a reversible counter 9, where the code from the converter 8 specified by sensor 1 is received. Well, the left code value of the signal under study goes to the input of the logometer 2, where the nominal signal is divided by the code and the zero value of the investigated voltage is fixed in the display device 3. Analogously calculating the voltage deviation, voltage fluctuation is determined with the only difference that the signals under study pass through blocks 11-14. The mode of measurement of the deviations of the investigated voltage. The investigated voltage V is fed to the bus 15. From the output of the driver 5, the pulses are fed to the multiplier b and block 4, which opens the key 7 to the time T. During this time, from the output of the multiplier to the input of the converter 8 passes n pulses that start the converter at times cc; . The codes of the instantaneous voltage values of the signal under study from the output of the converter 8 are transferred to counter 9, where the subtraction from the code proportional to the MC, given by the sensor 7 of the code proportional to V takes place, in accordance with the expression VH - v, - .4z.yH, -ISN, At the same time code NH; With the setpoint device 1 enters the logometer 2. After the subtraction operation in the counter 9, the code corresponding to the expression (1) also enters the logometer 2, where the codes are divided, according to the expression, and the indicator detects the deviation of the tested value from the nominal voltage. The mode of measurement of the fluctuations of the voltage under study. In this mode, the conversion of the voltage under investigation into digital codes and the setting of the measurement period occurs in the same way as the modes described above. After converting the instantaneous values of the voltage under investigation into digital codes N by the converter 8, they are fed to the inputs of blocks 13 and 14, which separate the maximum and minimum codes. During the measurement of TQ in blocks 13, 14, the minimum M, and maximum N are selected; . codes. These codes after the end and the time measured are recorded in blocks 11, 12 of the code transfer. On commands from control unit 4, the codes. And in turn are fed to the reversible counter 10 to the subtraction in accordance with the expression f, / in, ", .- n Wax vnin from the output of the counter 10, the agreement code (3) enters the cell 2 the logometer is dividing the investigated codes in accordance with the expression

and V х.) and .100% VH

This code enters the display device 14 and is recorded in it as the magnitude of the fluctuations of the voltage under study.

Thus, this device is characterized by high accuracy and speed and can be used to automatically control the quality of electricity in AC circuits.

Claims (2)

1. USSR author's certificate No. 591781, cl. G 01 R 19/04, 03/05/76 2. Energy and energy industry. 1965, №1, p. 22-23 (prototype).