SU1511718A1 - Device for monitoring current protection apparatus - Google Patents

Abstract

The invention relates to electrical engineering, in particular, to devices for testing AC current protection devices. The purpose of the invention is to increase the reliability of control results while reducing the labor intensity of the control. The device containing the current regulator 1, the switch 2, the load transformer 3, the time setting unit 6 and the rectifier unit 13 are inserted into the device, the current-limiting block 7, the second current indicator 8, the time indicator 9, the memory block 10, And 11, the block 12 forming the pulses and the second switch 14. The newly introduced elements and connections allowed us to apply a two-step switching on of the test current, the current of the first stage being used to determine the moment of switching on the main test current of the second stage in the phase that prevents the appearance of Shih harmonic components that reduce the accuracy of the monitoring results at all values of resistance and reactance checked proxy apparatus. The setting of the rated current of the tested apparatus is made based on the measurement of the currents of the first and second stages. 2 Il.

Description

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The invention relates to electrical engineering, in particular, to devices for testing AC current protection devices.

The purpose of the invention is to increase the reliability of control results while reducing the labor intensity of the control. through the use of a two-stage test current.

FIG. 1 shows the scheme of the device: Fig. 2 shows time diagrams explaining the operation of the device. The device contains series-connected current regulator 1, switch 2, load transformer; torus 3, current indicator 4 and first terminal for connection of the device under test 5, time setting unit 6, time limiting unit 7, current indicator 8, time indicator 9 ,: serially connected unit 10: memory, two-input element 11 I, pulse generating unit 12, power supply unit 13 and switch 14, with the output of current regulator 1 through the serially connected current limiting unit 7 and current indicator 8 connected to the output of the mutator 2 and the first input of the switch 14, the second INPUT of which is connected to the second output of the current-limiting block 7, the output of the memory block 10 through the setting unit 6. The time is connected to the control input of the switch 2, the second i output of the unit, 6 setting points time-and connected to the first input of the indicator 9: time, the second input of which is connected; It is not connected to the second terminal for the connection of the tested device 5, and the third input of the time indicator 9 is connected to the third output of the switch 14. The time setting unit 6 has an adjustable time setting for opening the input-output circuit.

The device works as follows.

The management of the indications of the current indicator 4, the current regulator 1 along the circuit of the block 7 of the current-limiting current indicator 8 and the load transformer 3 to the device under test 5 are fed a test current of arbitrary value, but less known than the rated current of its operation. At the same time, from the second outputs of the current-limiting block 7 and the current indicator B to the inputs, the switch 14 is supplied with voltage, corresponding to

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veino proportional to the load on the input of the load transformer 3 (and,, FIG, 2) and flowing

 on it is the primary current t. When the switch 14 is turned on, these voltages are sup- plied and the pulse shaping unit 12 is converted into pulses having a phase shift equal to the angle (The angle tf depends on the ratio of active and inductive resistances of the particular apparatus being tested 5 With the coincidence of the impulses 1 and at the output of the element 11, the voltage appears, which is stored by the memory unit 10 and through the time setting unit 6 is fed to the control input

20 of switch 2 Switch 2 is turned on, which leads to switching on the test current in the circuit of the tested apparatus 5, Since switch 2 is turned on at the moment when the voltage phase is equal to the phase angle of the current relative to voltage 1, and the instantaneous value of the current is zero, transient and higher harmonic components in the circuit

30 tested apparatus 5 is missing. When the tested apparatus 5 is activated, a signal to stop the 9th indicator will be given from its output, which will record its time

35 srabatse If the tested device 5 does not work, then the test current will be disconnected as a result of the control input circuit of the switch 2 disconnecting by the block 6 for 40 of the time sensor. Simultaneously, from the second output of the time setting unit 6, a signal is given to stop the time indicator 9. If the value of the test current mismatches node5 minal, then check repeat5pot.

In this case, a current is established in the circuit of the current-limiting unit 7 in which, after the switch 2 is triggered, a test current flowing through the device under test 5, which is equal to the nominal operating current, flows. The value of this current is easily determined from the ratio

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five

I l

I l

G-- I

where i

w g

- current of the first check in the circuit of the unit 7 current-limiting 5h

l current of the second check in the circuit of the unit 7 is current-limiting;

I. - test current of the first test. After switching on the switch 2;

I is the rated operating current of the apparatus.

The values of the currents 1 and ij are determined from the indications of the current indicator 8.

Thus, the newly introduced elements and connections allow replacing the single-stage switching on of the test current by a two-step one. In this case, the test current of the first stage is used to determine the moment of switching on the main test current of the second stage in a phase that excludes the appearance of higher harmonic components that reduce the reliability of the control results for any values of active and inductive resistances of the apparatus being tested, and setting the nominal current value The test of the apparatus to be tested is based on the measurement of the currents of the first and second stages.

Claims (1)

Invention Formula A device for testing current protection apparatuses, containing a series-connected Current Regulator, a switch, a load transform 5 0 5 0 five A torus, a gok indicator and first terminals for connecting a control object, a time master block, a rectifier block, characterized in that, in order to increase the reliability of control results while reducing the control panel, a time indicator, a current limiter, a memory block, the element I, the pulse shaping unit and the second current indicator and the switch, and the output of the current regulator through a series-connected current-limiting unit and the second current indicator are connected to the output of the first switch and the first input the house of the second switch, the second input of which is connected to the second output of the current-limiting unit, the first and second codes of the second switch are connected through the serially connected rectifier unit and the pulse shaping unit to the first and second inputs of the And element, the output of which is connected through the serially connected memory unit and the setting unit - the time clocks are connected to the control input of the first switch, the second output of the time setting block is connected to the first input of the time indicator, the second input of which is connected to the second terminals for connecting the control object, and the third time indicator input is connected to the third output of the second switch. FIG. 2