SU1376171A1 - Device for monitoring short-time voltage drops in phase of multiphase networks - Google Patents

Abstract

The invention relates to electrical engineering and is intended for use in alarm devices and the protection of electrical power systems. The purpose of the invention is to enhance the functionality by ensuring that the protection operates after a predetermined number of short-term voltage drops in the phases of the monitored network. In the full-phase mode of the controlled network, a Log is formed at the output of the serial limiter 3. 1 which is served

Description

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The inputs of the operative power source 5, the one-shot 8 and the counting input of the counter 9. At the output of the single-vibrator 8 and the discharge of the bits of the counter 9, a Log is formed. A. When the voltage drops in one of the network phases, the signal at the output of the limiter 3 takes the value Log. Oh, what causes the appearance at the output of a single-shot 8 Log. 1, which is fed to the input Resetting the counter 9, allowing the counter to operate in the counting mode. If during the time of setting the one-shot 8 to the counting input of the counter 9 will receive a specified number

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The invention relates to electrical engineering and is intended for use in alarm devices and the protection of electrical power systems.

The purpose of the invention is to enhance the functionality by providing protection after a zag, a given number of short-term voltage drops in the phases of the monitored network.

Figure 1 presents the scheme of the device; Fig. 2 is a timing diagram explaining its operation at a network frequency of 50 Hz.

The device for monitoring short-term voltage drops in the phases of a multiphase network contains a multiphase half-wave rectifier 1 with output terminals for connecting to the phases of the controlled network, voltage divider 2, serial voltage suppressor 3, actuator 4 and operational power source 5. The voltage divider 2 is connected by the first end terminal to the half-wave rectifier 1 output and has a second terminal terminal for connecting to the neutral conductor 6 of the network, and the operational power source 5 has an input terminal, an output terminal for connecting to the device power inputs and a common terminal for connecting to the second terminal of the splitter 2

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counting pulses, the outputs of the bits of the counter 9 will form a predetermined combination of signals, the actuator 4 will operate, while the electrical consumer is disconnected from the monitored network. When less than a specified number of counting pulses arrives at the counting input of the counter 9, the specified combination of signals at the outputs of the bits of the counter 9 is not formed, the actuator 4 does not work. After testing the time setting of the one-shot 8, the counter 9 returns to its original state. 3 hp f-ly, 2 ill.

tension The device has a parallel voltage limiter 7, a one-shot 8 and a counter 9.

The input terminal of the parallel voltage suppressor 7 is connected to the middle terminal of the voltage divider 2. The output terminal of the parallel voltage limiter 7 is connected to the input terminal of the serial voltage limiter 3. The common terminals of parallel 7 and serial 3 voltage limiters are connected to the second terminal of divider 2

tension The output of the serial voltage limiter 3 is connected to the input of the one-shot 8, the counting input of the counter 9 and the input output of the operational power supply 5. The output of the one-shot 8 is connected to the zero input of the counter 9, The bit outputs of the counter 9 are connected to the inputs of the actuator 5.

A parallel voltage limiter 7 is provided on the first resistor 10 and the first Zener diode 11, and the voltage limiter 3 is connected to the second Zener diode 12 and the second resistor 13 successively. In the parallel voltage limiter 7, the first terminal of the first resistor 10 is connected to the input terminal common point of the second output

the first resistor Yu and the first output of the first Zener diode 11 is connected

with the output terminal, the second terminal of the first zener diode 11 is connected to the common terminal of this voltage limiter. In the series limiter 3 of the voltage, the first terminal of the second Zener diode 12 is connected to the input terminal, the common point of the second terminal of the second Zener diode 12 and the first terminal of the second resistor 13 is connected to the output terminal, the second terminal of the second resistor 13 is connected to the common terminal of this limiter wives The first 11 and second 12 zener diodes are connected to the membrane with the same electrode. Operational power supply 5 is made on series-connected diode 14 and capacitor 15, the first lead of diode 14 is connected to the input lead of the operational power supply 5, the common point of the second lead of diode 14 and the first lead of capacitor 15 is connected to the output lead, and the second lead of capacitor 15 is connected with a common output of the operative power source 5. Counter 9 has an additional input. A ban is connected to the output. Actuation of the executive body 4. Executive body 4 is made on the connecting diodes 16, switch 17, repeater 18 HE 19 element, actuator 20 equipped with contacts 21. Single vibrator 8 is made on the element AND-NOT 22, the elements NOT 23 and 24, the capacitor 25 and the resistor 26. The counter 9 in addition to the actual counter 27 contains the input element NOT 28 and the element AND-NOT 29.

The device works as follows.

In the case of a full-phase network operation, from the output of the rectifier 1, a pulsating voltage of positive polarity is supplied through the voltage divider 2 to the limiters 7 and 3. Figure 2 shows the cutoff level of the parallel limiter 7 (U ,,) and the series limiter 3 (and ). In the established full-phase network mode, a log is formed at the output of the limiter 3. 1 (high potential), which is fed to the inputs of the operational power supply 5 and the one-shot 8 and to the counting input of the counter 9. The output of the one-shot 8 and the outputs 5 0 5 O

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 The rows of the counter 9 form a log. A. Counter 9. is in the initial state.

When the voltage of one of the phases (Φ, - Fz) of the network, for example, phase FZ, decreases below the permissible level, the signal at the output of the limiter 3 in the time interval t, - t (Fig. 2) takes the value of Log. Oh, what causes the appearance at the output of a single-shot 8 Log. 1, which is fed to the input Resetting the counter 9, allowing the counter to operate in the counting mode. Signal Log. About from the output of the limiter 3 is fed to the counting input of counter 9, the transfer of the counter to the next state. If during the setpoint period of the one-shot 8, when the signal at the output of the one-shot is set to Log. 1, a predetermined number of counting pulses will be sent to the counting input of the counter 9, the outputs of the bits of the counter 9 will form a predetermined combination of signals that will trigger the actuator 4, close the contacts 21 and increase the signal from the output Actuating the actuator 4 to the input 9, while the electrical consumers are disconnected from the monitored network.

If during the setpoint time of the one-shot 8 to the counting input of the counter 9 less than a predetermined number of counting pulses are received, the output combination of the counter 9 will not generate the specified signal combination and the actuator 4 will not operate. After working off the time setting on the extrusion of the one-shot 8, a log is formed. O, which is inputted to resetting the counter 9 and resetting the counter 9 to the initial state.

Further operation of the device during short-term decreases in the voltage of the phases of the multiphase network is carried out similarly to that described. Using the switch 17 of the executive body 4, any allowable number of voltage drops in the phases of the monitored network during the set-up time of the one-vibrator 8 can be specified.

The positive effect of the invention is to expand the functionality of the device.

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Claims (4)

1. A device for monitoring short-term voltage drops in multiphase network phases, containing a multiphase single-half-rectifier with input terminals for connection to the controlled phases.1 (oh network, voltage divider, series voltage limiter, actuator and operational power source, moreover the voltage divider is connected to the output of the half-wave rectifier by the first end terminal and has a second terminal for connection to the zero current network, and the operational power source It has an input terminal, an output terminal for connecting to the power inputs of the device elements and a common terminal for connecting a voltage divider to the second terminal, characterized in that, in order to extend the functionality by ensuring that the protection is triggered after a predetermined number of short-term voltage drops in phases a monitored network, a parallel voltage limiter, a one-shot and a counter are entered into it. The input terminal of the parallel voltage limiter is connected to the middle output of the divider and the output view is connected to the input output of the serial voltage limiter, the common terminals of the parallel and serial voltage limiters are connected to the second terminal output of the voltage divider, the output terminal of the serial voltage limiter is connected to the input of the single-oscillator, the counter input of the counter and the input voltage limiter. the output of the operative power source, the one-shot output is connected to the counter-zeroing input of the counter, the outputs of the discharge bits of the counter are connected to the inputs of the actuator. 0 five 0 one five 0 five 0 five 716 2. The device according to claim 1, about tl and the fact that the parallel voltage suppressor is made on - successively connected to the first resistor and the first Zener diode, and the series voltage suppressor on the series-connected Second Zener diode and the second resistor, and in parallel the voltage limiter, the first terminal of the first resistor is connected to the input terminal, the common point of the second terminal of the first resistor and the first terminal of the first zener diode is connected to the output terminal, the second terminal of the first zener diode dinene with the general conclusion of this voltage limiter and in the series voltage limiter, the first output of the second zener diode is connected to the input output, the common point of the second output of the second zener diode and the first output of the second resistor is connected to the output output, the second output of the second resistor is connected to the common output of this voltage limiter, and the first and second zener diodes are connected identical electrodes. 3. The device according to claim 1, about tl and - the fact that the operational power source is made on a series-connected diode and capacitor, the first output of the diode connected to the input output of the operational power supply, the common point of the second output diode and the first output of the capacitor connected to the output terminal, and the second output of the capacitor is connected to the common output of the operational power source. 4. The device according to claim 1, about tl and - the fact that the meter has an additional input A ban on the account connected to the output of the actuator. F6 FIG. Z