SU1357870A1 - Converter for insulatition resistance checking device - Google Patents

Abstract

The invention can be used to automatically monitor the condition of isolating various objects. The purpose of the invention is to increase the speed of control of insulation resistance. The converter contains n test circuits 3.1, ... p.p, switching unit 5, contact pear 6, relay 7, voltage source 11, comparison block 12, voltage reference source 13, element 14, ISH1 element 15, block 16 delays, a key circuit 17 and a time delay setting of 18. The introduction of contact group 9 and the formation of new functional connections provide a preliminary charge of shunt capacitors 4.1, ..., 4.n in each circuit under study. 1 il. oo ate 00 o

Description

The invention relates to electrical measuring equipment and can be used to automatically control the state of the insulation resistance of various objects containing a large number of electrically disconnected circuits that are bridged by capacitors.

The purpose of the invention is to increase the speed of insulation and to control the insulation resistance of the studied circuits shunted by capacitors due to the preliminary accelerated charge of the shunt capacitors in each circuit under study.

The drawing shows a block diagram of a converter for an insulation resistance monitoring device,

The converter contains 1.1-1-1 p terminals for connecting the control object 2, containing p-test circuits 3.1-3, p, shunted by capacitors 4.1-4, p, respectively. Terminals 1.1-1, p for connecting the control object 2 are connected to the corresponding inputs of the switching unit 5 whose output is connected respectively via the first normally closed contact group 6, relay 7 and the first low-resistance resistor 8 to the common bus, via the second normal a closed contact group 9, a relay 7 and a second low-resistance resistor 10 with the output of the measuring source 11 voltage, with the first input of the comparison unit 12 j and the second and third inputs of which are connected to the outputs of the measuring 1 1 and the reference 13 voltage sources Naturally, the output is connected to the first input of the AND 14 element and the first input of the OR 15 element, the output of which is connected to the second input of the AND 14 element, to the first inputs of the delay block 16 and the key circuit 17, which controls the input of the switching unit 5, the first key output The circuit 17 is connected to the second input of the SHSh 15 element via the time delay setting device 18, and the second output is connected to the common bus through the winding of the relay 7, the output of the delay block 16 is connected to the second input of the key circuit 17, the zero bus 19 is connected to the O inputs switching unit 5 and to yuchevoy circuit 17, respectively, the tire 20 Start transducer connected to the third input element

OR 15, the output element AND 14 is the output of the converter.

The Converter operates as follows.

After giving the signal to Zero bus 19, the switching unit 5 is nullified and thus none of the monitored circuits 3.1-3, n of the object 2 of the control is not connected to the input of the comparison unit 12. In addition, key circuit 17 is zeroed at the corresponding input, providing relay 7 is de-energized. After the Start-up signal is sent, the third input of the OR element 15 will output a logic level 1 signal at its output, which delays the delay unit 16 and enters the control input of the switching unit 5, providing a connection to the first input of the unit, 12 comparing the first test circuit 3.1, shunted by the large capacitance of the capacitor 4.1. Both contact groups 6 and 9 of the relay 7 are initially in the initial state , providing a connection to the output of a measuring voltage source 11 of a low-impedance voltage divider formed by the first B and second 10 low-resistance resistors. Moreover, the lower arm of the divider (the first resistor 8) shunts the test circuit 3.1, onto the case. As a result, a preliminary accelerated charge of the capacitor of the capacitor 4.1, shunting the test circuit 3.1, occurs, through a low impedance secondary 1: resistor 10,

The charge of capacitor 4.1 occurs to a voltage value determined by a low impedance divider corresponding to a value less than the reference voltage by the absolute error of the device as a whole.

After a noncontrol time set in delay block 16, during which the capacitor 4.1 of the circuit 3.1 being charged is fully charged, the signal from the output of delay block 16 is fed to the second input of the key circuit 17, as a result of which the relay 7 is activated. Normally the closed contacts 6 and 9 of the relay 7 are disconnected, the object 2 of the control is disconnected from the action of the low-resistance resistor divider, the voltage and the circuit 3.1 under investigation is represented by the establishment of the actual voltage in it corresponding to the real value insulation resistance. At the same time, from the first output of the key circuit 17, a signal is received that triggers the time delay setting device 18, which is set to the maximum possible duration of time to completely complete the transition charge process in the circuit 3.1 under investigation by the bypass capacitor A.1. During the period of shunting and immediately after shunting of the tested circuit 3.1, at the output of the comparison unit 12 there is a logical O signal, which corresponds to the sign of poor-quality insulation. If the insulation resistance of the circuit under study is greater than the allowable threshold, then after some time, determined by the metering of capacitor 4.1 from the measuring voltage source 11 through a high resistance, the resistor included in the comparison unit 12 between its first and second inputs, At the output of the comparison unit 12, a logical 1 signal appears before the end of the time set in time delay adjuster 18. As a result, early termination of the cycle of the control of the circuit under study and transition by the switching unit 5, the delay block 16 and the key circuit 17 to the control of the next circuit 3 occur. The signal about the insulation quality of the circuit under study passes through the AND 14 element to the device output.

In the case when the insulation resistance of the circuit under study is less than the permissible threshold value, the logic signal O at the output of the emergency unit 12 is maintained for the entire period determined by the time delay adjuster 18, closing the AND 14 element, which registers the poor insulation resistance of the circuit under study . The completion of the control cycle and the transition to the control of the next circuit under investigation occur after the end of the editor. Head 0.

Compiled by A. Komissarov Tehred A. Kravchuk

Order 5994/45 Circulation 730 Subscription

VNIIPI USSR State Committee

for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5

Production and printing company, Uzhgorod, st. Project, 4

5 o 5 Q

0

five

PIA installed in time setting device 18.

Claims (1)

Invention Formula A converter for an insulation resistance monitoring device that contains terminals for connecting a control object, connected to the corresponding inputs of a switching unit, the output of which is connected to the first output of the first normally closed contact group of the relay and the first input of the comparison unit, the second and third inputs of which are connected respectively to the source outputs measuring and reference voltages, and the output is connected to the first inputs of the OR element and the AND element, the second input of which is connected to the output of the OR element, with the control input of the switching unit and the first inputs of the delay unit and the key circuit, the first output of which is connected to the second input of the OR element through the time master setting, and the second output is connected to the first output of the relay winding, the second output of which is connected to the common busbar, the first and second low-impedance resistors, the output element And is the output of the converter, the output of the delay unit is connected to the second input of the key circuit, characterized in that, in order to increase the speed of the conversion, the second normal is introduced into it but the closed contact group of the relay connecting the output of the switching unit with the output of the measuring voltage source through the second low-impedance resistor, while the first normally closed contact group of the relay connects the output of the switching unit with the common converter bus to the installation inputs via the first low-resistance resistor In the switching unit and the key circuit, the converter start-up bus is connected to the third input of the OR element. Proofreader G. Reshetnik