SU1401410A1 - Device for central monitoring of insulation resistance of electric distribution network - Google Patents

Abstract

The invention relates to the field of electrical measuring equipment and can be used to control the insulation resistance of branched electrical networks. The purpose of the invention is to increase the control speed - achieved by automating the polling of control objects. Another goal is to increase control accuracy and improve.

Description

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improvement of electrical safety conditions is achieved by dosing the measurement time for the minimum and maximum. The device contains an isolation transformer 1, a rectifier 2, a source of operational rectified current, a megohmmeter 4, an operational measuring transducer 5, a threshold unit 6, an alarm unit 7, a device operation test unit 8, a central switch 9, a connection10

body cable 10, shop switches 11, calibrated resistors 12, magnetic actuators 14 with movable contacts 13, shop distribution networks 15, insulation resistances 16, compensation unit 17, shop generators 18 clock pulses, shop counters 19 pulses, shop decoders 20 , central counter 21 pulses and central decoder 22. 1 Il.

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The invention relates to electrical measuring equipment and can be used to control the insulation resistance of branched electrical networks.

The purpose of the invention is to increase the control speed by automating the survey of control objects, improving the control accuracy and improving electrical safety conditions by metering the measurement time for the minimum and maximum.

The drawing shows the block diagram of the device.

The device contains an isolation transformer 1, a rectifier 2 power supply circuits, a source 3 of operational rectified current, a megohm meter 4, an operational measuring transducer 5, a threshold unit 6, an alarm unit 7, a multilevel unit 8 for checking the operation of the device, the central switch 9, a connecting cable 10, workshop switches 11, calibrated resistors 12, moving contacts 13 disconnecting contacts of magnetic starters 14, shop distribution networks 15, insulation resistances 16, compensation block 17, shops 18 clock pulsers, shop counters 19 pulses, shop decoders 20, a central counter 21 pulses and a central decoder 22.

The first output of the transformer 1 is connected to the first input of the rectifier 2, and the second to the first input of the source 3, the second input of which is connected to

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the first output of the converter 5, the second output of which is connected to the first input of the threshold block b, the first output of which is connected to the first input of the converter 5, the second input of which is connected to the input of the block 17 and the grounding switch and to the first output of the block 8, the input of which is connected to the output of the source 3 and the second output is connected to the input of the central switch 9, the outputs of which are connected to the inputs of the corresponding workshop measuring switches 11, the first outputs of each of which are grounded through the calibrated resistors 12, and the rest of you. the strokes are connected to the corresponding moving contacts 13.

The output of the compensation block 17 is connected to the output of the megohm meter 4, the input of starting each of the generators 18 is connected to the input of the corresponding switch 11, and the output is connected to the counting input of the corresponding counter 19, the output of each of which is connected to the input of the corresponding decoder 20, the output of each of which is connected to the control input of the corresponding switch 11, the last output of each KOTopbtx is connected to the Stop input of the corresponding generator 18, the Reset input of the corresponding counter 19 and the corresponding input of the counter 21, the output of which oh is connected to the input of the decoder 22, the output of which is connected to the control input of the switch 9, while the last output of the n-th switch 11 is connected to the Reset input of the counter 21.

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The device works as follows.

When the device is connected to the mains (source of alternating current), the voltage from transformer 1 is fed to the inputs of rectifier 2 and source 3. The voltage from the output of rectifier 2 is fed to the input of unit 7 and through its output to the first input - 10 horn block 6 for feeding their schemes. The voltage from the output of source 3 is applied to block 8. The device is in the initial state.

Before starting to directly control the insulation resistance level of distribution electrical networks, a check is performed on the operation of the device by switching on the operation of unit 8. This creates a flow circuit of the instantaneous rectified current through a block 8 resistor (source output 3 operational rectified current - input of the unit 8 for checking the operability of the device; 5), one of the positions of the multi-position switch and the calibrated resistor of the unit 8 for checking the operability of the device TWA - its first output - grounded input 30 of converter 5 - its first output - megohmmeter 4 - second input of source 3. At the same time, voltage at the other output of converter 5 is proportional to the value of the current flowing in the circuit and fed to the second the input of the threshold unit 6, as a result of which a light and sound alarm is given, indicating that the device is working. 40

At the end of the health check operation, the device is multi-position

the switch of the unit 8 for checking the operation of the device is set to the position where the switch 9 is connected to its 45 output, and from this position, the insulation resistance levels of the shop distribution electric networks are monitored automatically. 50

When an operator or a special software program acts on a button with a closing contact, a 55-mp pulse is sent to the counting input of the central pulse counter 21, which through the decoder 22 creates the center switch 9, as a result of which the first output switches

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to its entrance and through the cable conductor

10 voltage from source 3 is fed to the input of the first workshop switch

11 and the trigger input of its generator 18 clock pulses. Clock pulses arrive at the counting input of the workshop counter 19 pulses, which through the decoder 20 controls the switching of the workshop measuring switch 11, alternately connecting all of its outputs from 1 to n to its input, thereby automatically monitoring the insulation resistance levels shop distribution electric networks.

Upon completion of the survey of all monitored distribution networks of the first workshop from the last output of the first workshop switch 11, the control signal is input to the generator. Stopping the generator 18 clocks, input Reset of the counter 19 pulses, driving them and their controlled elements to their original state, and counting input central counter 21. The incoming signal is received by counter 21 and through the decoder 22 switches the central switch 9, as a result its second output is connected to its input and Om core 10 of the control cable, the voltage from the source 3 of the operational rectified current is fed to the input of the second workshop switch 11 and the trigger input of its generator 18 clock pulses. Further, the work is carried out as described in Bbmie.

Upon completion of the survey of all monitored electrical distribution networks of all workshops since the last output of the last workshop switch

11The control signal is input to the Reset of the central counter.

21 pulses, driving it. And the elements controlled by it into the initial state. The device is ready for the next survey cycle of controlled shop distribution electrical networks. Here, the cycle described above is repeated.

Claims (1)

Invention Formula A device for centrally monitoring the insulation resistance of electrical distribution networks. 514 containing a source of operational rectified current, power supply rectifier, megohmmeter, operational measuring transducer, compensation unit, p shop measuring commutators, central switchboard, multilevel device health check, threshold unit, alarm unit, as well as a separation transformer whose input is connected to an AC power source, the first output of the isolation transformer is connected to the first input of the power supply rectifier, and the second (. The swarm is connected to the first the input source of the operative rectified current, the second input of which is connected to the output of the megohmmeter, the input of which is connected to the first output of the operational measuring converter, the second output of which is connected to the first input of the threshold unit, the first output of which is connected to the first input of the operational measuring transducer the former, whose second input is connected to the input of the compensation unit, to the grounding conductor and to the first output of the operation conditioner, the device whose input is connected to the output of the source is opera ivnogo rectified current, and a second output connected to the input central commutator a- torus, whose outputs are connected to inputs of the corresponding shop measurement mis- switches, the first outputs of each of which resistors is grounded through a tared, and the remaining outputs are connected to corresponding moveable contacts NC block 5 0 0 5 0 five 106 contacts of the magnetic actuators of the control objects, and the output of the compensation unit is connected to the output of the megohmmeter, characterized in that, in order to improve the control speed by automating the survey, control objects, improving the control accuracy and improving the electrical safety conditions by metering the measurement time on the minimum and maximum, a central pulse counter, a central decoder, p shop pulse counters, p shop decoders, n shop clock pulse generators, Start input are entered into it to each of which is connected to the input of the corresponding workshop measuring switch, and the output is connected to the counting input of the corresponding workshop pulse counter, the output of each of which is connected to the input of the corresponding workshop decoder, the output of each of which is connected to the control input of the corresponding workshop measuring switch, the last output of each of which is connected to the Stop input of the corresponding workshop clock pulse generator, the Reset input corresponds, its shop counter pulse and with the corresponding counting input of the central pulse counter, the output of which is connected to the input of the central decoder, the output of which is connected to the control input of the central switch, while the last output of the nth workshop switch is connected to the reset input of the pulse counter.