SU1026120A1 - Switch commutation wear registering device - Google Patents

Abstract

A DEVICE FOR REGISTRATION OF SWITCHING COMMUTATION WEAR, containing master unit of logical unit, summing counter of time intervals, voltage converter - time interval, connected by the first and second inputs to the corresponding first and second terminals of the capacitor, the current source connected by the first terminal through the limiting resistor to the terminal for connection of the first pin of the tested contact of the controlled switch, current sensor connected by electromagnetic connection with the current circuit of the tested of contact-breakers, which distinguishes with the fact that, in order to increase Dost,; fidelity control, voltage sources, first, second and third switches, diodes, measuring relays, one-shot, voltage gain change unit, time interval, AND element, connected to the input to the summing counter of time intervals, first input through normal - closed, the first switch g with the first output of the setpoint adjuster of the logical unit, the second input - with the output of the voltage converter - the time interval connected by the third input through the unit is changed the voltage transfer coefficient of the voltage converter - and the time interval, the one-shot and the normally-open second switch - with the second output of the voltage generator of the logical unit, Fri 6 input through the normally open third switch - with the cathodes of the diodes / the first input - with positive, voltage source terminals, negative terminals which are connected through but {1-open-ended contacts of the associated measuring relays with cathodes, corresponding diodes, windings of the measuring relays are connected after ovatelno and connected to the output of the current sensor.

Description

The invention relates to the control of the measuring technique and can be used to register the switching wear of switches.

A device for determining the switching wear of breakers is known, performed on a multi-definite counter G.

The known device has a low accuracy due to the fact that it does not take into account the wear when the switch is turned on, including when turned on for a short circuit.

Closest to the present invention, there is a device for automatically detecting switching wear of circuit breakers, comprising an up-to-date one; the capacitor connected via the auxiliary contact of the switch and in the "" terminal to the current sensor, the primary circuit of which is connected in series with the switch, the voltage conversion unit in the time interval and the summing counter of time intervals (2j.

A disadvantage of the known device is that it does not take into account the change in the degree of wear depending on the magnitude of the switched current - and does not take into account the presence of ejac when the switch is turned on for a short circuit or overload.

The purpose of the invention is to increase the reliability of the control.

The goal is achieved by the fact that the device for registering the 1-watt wear of switches contains a master unit control unit, a summing counter for 11 $ interval, a voltage converter for the time interval connected by the first and second inputs to the corresponding first and second capacitors, the current source connected by the first output through the limiting a resistor with a terminal for connecting the first pin of the test contact of the monitored switch, a current sensor connected by an electromagnetic With the current circuit of the test switch contact, voltage sources, first, second and third switches, diodes, measuring relays, one-shot, voltage-gain transfer unit of the voltage converter — time interval, AND input connected to the input of the summing counter of time intervals the first input through Normally closed first switch - with the first output of the logic unit, the second input - with the output of the voltage converter - the time interval connected by the third black The unit for changing the transfer coefficient of the voltage converter is a time interval, a one-shot and a normally open second switch - with a second output of the voltage generator of a logical unit, the second input through a normally open third switch - with diode cathodes, the first input - with,. the terminals of the voltage sources, the minus terminals of which are connected through normal times, the open contacts corresponding to the measuring relays with the cathodes of the corresponding diyds, the windings of the measuring relays are connected after e sequence and is connected: to the output of the current sensor.

The drawing is a schematic diagram of the device.

The device contains the first current source 1, the limiting resistor (load equivalent) 2, the test switch 3, the third 4, the second 5 and the first 6 switches, the current sensor 7, measuring relays 8, voltage sources 9, diodes 10, capacitor 11, setpoint 12 logical unit, one-shot 13, block 1.4 of the change of the transmission coefficient of the voltage converter - time

0 interval, voltage converter 15 — time interval, AND 16 element, summing counter 17 time intervals.

The device works as follows.

5 way.

Switch 3 switches (turns on or off.) The load circuit 2 supplied from the current source 1, the current value of the switched circuit is measured by the current sensor 7, the secondary circuit of which includes measuring relays 8 with controlled (mechanically or electrically) trigger . Each relay 8 is configured to its own threshold of operation, and their number can be any depending on the required number of levels into which the entire range of normal and emergency modes flowing through switch 3 is broken. Each current level that is turned off

switch 3, corresponds to a certain degree of wear of the switch. Each of the sources 9 of the calibrated voltage is turned on or off in the charge circuit of the capacitor 11 by the contact of the corresponding relay .8, The voltage of each of the sources 9 is different, it is proportional to the degree of wear you-.

0 key 3 when it turns off such a current that triggers the corresponding relay a. As a result, measurement relays 8, having different response thresholds,

5 connects to the charge circuit of the condenser 11 those of the sources 9, the voltage of which corresponds to the degree of wear of the switch 3 at a long switching current.

With a large value of the current switched by the switch 3, not only the relay 8 is triggered, the threshold from which is lower than this current value. In the charge circuit of the capacitor 11, only one source 9 is connected, the calibrated voltage of which corresponds (proportionally) to the switch wear at a given level of switched current.

This is achieved due to the fact that of all the diodes 10 only the one that is connected to the source 9, whose voltage is the highest, is opened. Diodes 10, connected successively with the other sources 9, having a lower voltage, are locked.

The voltage on the capacitor 11 is converted into a time interval by means of a converter 15. The proportionality factor of the conversion of a voltage level to a time interval changes block 14. When a signal is applied to the input of block 14, it increases the gain of the converter 15 by a predetermined value. The single-oscillator 13 forms a predetermined time interval and is intended to put the unit 14 into operation only for a predetermined time.

The operation of the device when turning off the switch 3 is as follows. Until the current is turned off, the current flowing through the load 2 and the primary setting circuit. 7 causes the operation of those relays 8 whose threshold is lower than or equal to the value of this current. Switch 4 is on, switch 6 is off. Counter 17 is disconnected, and storage capacitor 11 is connected to sources 9 of calibrated voltages. Capacitor 11 is charged before voltage. source 9, the magnitude of the voltage of which is the greatest over all other sources on 9. Before the moment when the switch 3 is turned off, the capacitor 11 is charged to a voltage whose value is proportional to the switch's wear, which must be fixed when the current is turned off. the switch 3 opens the switch 4 and disconnects the capacitor 11. from the sources 9. The discharge of the capacitor 11 to the converter 15 begins.

The output signal of the converter 15 is fed to the first input element AND 16. The second input of the element receives a signal from the unit 12 of the logical unit through the switch 6, which is turned on when the switch 3 is turned off. When the switch 3 is turned off, the signal that turns on the counter is generated at the inputs of the element 16 17 time intervals.

After a time proportional to the initial voltage on the capacitor 11, the last discharge and the permitting signal at the output will convert; if 15 stops to act on the element 16, which will cause the counter 17 to stop, Counter 17 will count the time proportional to the initial voltage on the capacitor 11 ,

5 i.e. the degree of wear of the switch, depending on the magnitude of the disconnected current,

In the cycle for short circuit, the shutdown device operates as follows. Until the switch 3 is turned on, the switches 4 and 5 are off, the capacitor 11 is discharged, the output signal of the converter 5 has no enabling signal, the AND 16 element is closed, the counter 17 does not work. When the switch 3 is turned on, the switches 4 and 5 are turned on, the switch is turned off, so the meter 17 does not work.

0

The closed switch 4 connects the capacitor 11 to the sources 9, the cycle is turned on, automatic shutdown can take place only if the switch 3

5 is switched on for emergency operation of the load 2, for example, a short circuit and is automatically switched off by the relay protection. In this cycle, the circuit breaker is in the on position

0 for a period of time equal to the sum of the time of relay protection and the intrinsic time of the tripping mechanism of the switch 3. During this time, the measuring relays 8 having a threshold are triggered.

5 operation equal to or less than the amount of current flowing through the switch 3, and the capacitor 11 is charged in the manner indicated above to the voltage of that source 9,

0 the magnitude of the voltage at which is the greatest.

Simultaneously with this, at the moment of switching on the switch 3, the switch 5 switches on and the unit 12 of the logical unit starts the one-shot 13, which activates the block 14 of the change of the transfer coefficient of the converter 15.

at block 14, the gain is increased.

After switching off the switch 3 in the manner described above, the capacitor 11 is discharged to the converter

15, which, together with the closed switch 6, starts the counter 17, since the converter 15 operates in this case with an increased value of the transfer coefficient, then the increased value of the time interval corresponding to the total wear on the switch is recorded on the counter 17. emergency current, and shutdown of the same current by it. The longest recording time of information in the totalizing counter of time intervals after each disconnecting switch should not exceed the pause time in the cycle of its automatic re-activation. The duration of the output pulse of the one-shot 13 is longer; It is the sum of the tripping times of the relay protection of the switch 3, the disconnection time of the vault and the time of recording information into the summation counter 17 and the time intervals and less than the sum of the response time of the relay protection of the tripping time of the switch and the pause time in the automatic re-activation cycle of the switch 3. Increasing the ratio transfer of converter 15 by block 14 is chosen so that the resulting time interval, counted by counter 17, is proportional to the total switching wear in the cycle switching on, automatic switching off With this selection of the pair: the oHOi device will always be prepared to register wear, both for operational switching and for switching off the switch, as well as for automatic switching. regardless of their number and the time interval between them. If the switch-off switch 3 does not happen before the expiration of the operation time of the one-vibrator 13, the one-shot returns to the initial state and shuts down the block 14. At the same time, the transfer ratio of the circuit 15 decreases to the level corresponding to wear when the switch-off 9 returns to the initial state On the other hand, the switch 3 was turned on for the normal load mode 2, the switching wear in which is so small that its registration is not required. Thus, the proposed device allows to take into account the wear of the switch when turned on for a short circuit, which improves the accuracy of control.

Claims (1)

DEVICE FOR REGISTRATION OF COMMUTATION WEAR OF CIRCUIT BREAKERS, containing a logical unit controller, summing the counter of time intervals, voltage converter “-time interval connected. the first and second inputs with the corresponding first and second terminals of the capacitor, a current source connected to the first output through the limiting resistor with a terminal for connecting the first output of the test contact of the controlled circuit breaker, a current sensor connected by electromagnetic coupling to the current circuit of the tested contact of the circuit breaker, different the fact that, in order to increase access to \ '. fidelity of control introduced into it | voltage sources, first, second and third switches, diodes, measuring relays, one-shot, unit for changing the transfer coefficient of the converter voltage time interval, element And, connected by an output to the input of a summing counter of time intervals, the first input through a normally-closed first switch - with the first output logic unit, the second input - with the output of the converter voltage is the time interval connected by the third input through the block change the transfer coefficient of the Converter n temporary voltage. interval, one-shot and normally open second switch - with the second output of the logic unit voltage regulator, the third input through the normally open third switch - with the cathodes of the diodes, the first input - with the positive terminals of the voltage sources, the negative terminals of which are connected through the normal open contacts of the corresponding measuring relays with cathodes, corresponding diodes. The windings of the measuring relays are connected in series and connected to the output of the current sensor. „SUU 026120