SU1476551A2 - Apparatus for protection of three-phase electric installation against nonsymmetric modes - Google Patents

Abstract

This invention relates to relay protection. The aim of the invention is to extend the functionality by ensuring that all elements of the device are monitored and that the protection is set up without being disconnected from the work network. The goal is achieved by the fact that the device is additionally equipped with a resistor, a signal element and a three-position switch with two opening and one closing contacts, an additional resistor is connected in parallel through the closing contact of the switch (in the "Test" position) to the RC resistor - a single-shot target with a restart. The signaling device is connected to one of the actuator outputs, and to the other output are connected in series connected disconnecting contacts of the switch (one contact corresponds to the position of the “Check” switch, and the second one - to the “Setting” position). An additional resistor through the switch contacts changes the triggering setting, and the actuation of the actuator is blocked by the break contact contacts. The alarm element provides information about the state of the elements of the security device and allows you to check and adjust the protection. 1 il.

Description

pi start the one-shot 4 with restart, the inverse output of which is connected to the input of the storage element 5 connected by its output to the input of the actuating element 6, additional resistor 7, switch 8 with closing contact 9 and opening contacts 10 and 11, as well as element 12 of the alarm ( containing LEDs or warning lights signaling the device's mode of operation: Normal operation, protection tripped.

An additional resistor 7 is connected in parallel through the closing contact 9 (switch position Check) to the resistor RC circuit of the one-shot 4, and the signal element 12 to the output of the actuator 6, the disconnecting contact 10 of the switch 8 is connected to the output of the actuator 6 (corresponds to the position of the switch Check) and in series with it is the disconnecting contact 11 of switch 8 (corresponds to the position of the Setting switch).

To check the device operability, it is necessary to put the switch 8 into the position. At the same time, contacts 9 are closed, one-vibrator resistor 4 is connected in parallel, additional resistor 7 is reduced, the total resistance of the single-circuit RC circuit decreases, which leads to a decrease in the TRC response setting, The appearance of a single-shot 4 pulses. When they are repeated several times, the accumulation element 5 turns on the actuator 6, which connects the signal element 12 signaling that the protection has been activated, however, the installation is not turned off, because the signal from the actuator 6 of the protection device does not pass to the tripping circuit as the circuit is interrupted by the break contact 10 of switch 8 .

When setting the protection of the switch 8, they are set to the Setting position, while the break contact 9 of the switch 8 breaks the circuit to shut off the protected installation. By adjusting the resistor of the one-shot 4, the protection device, i.e. to fulfill the condition T ds, about the nrc sig loads the element

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alarms. Thus, it is possible to provide a detuning from the asymmetry of the network, increasing the resistance to the value at which the signal that the protection is activated disappears.

When the position of the switch 8 Work position of the scheme corresponds to that shown in the drawing. With the occurrence of violations in the protected network, the condition T Rx TRc is satisfied, the installation is turned off and the signal element signals that the protection has been activated.

The actuator is turned on so that during normal operation it flows around the current, and when the protection is activated, it de-energizes and makes the necessary shutdowns. Such a mode of its operation allows constant monitoring of the health of all the circuits of the device, since the failure of any element or the disappearance of voltage leads to a shutdown of the installation, which can be restarted by service personnel after the reasons for shutting down the installation have been determined.

The invention provides verification and adjustment, monitoring and signaling of the state of the protection device, thereby improving the reliability of the protection device and reducing the time costs associated with performing these operations. In addition, the use of such a scheme allows to reduce the consumption of electricity consumed at the load stand of the protection setting.

Claims (1)

Invention Formula Device for protection of three-phase electrical installation from asymmetrical modes according to avt.ev, No. 1309164, which is due to the fact that, in order to extend the functionality by providing performance monitoring and protection setting without disconnecting from the working network, a resistor is added to it, an alarm element and a three position switch, including a neutral one, the output of the first fixed contact of said switch is functionally connected to the newly introduced closing contact, which forms a series a chain with a resistor connected parallel to the resistor RC-chain of the one-shot, this the same output is functionally connected to the newly introduced first disconnecting contact, the first output of which is connected to the output of the actuator and to the input of the alarm element, the output of the second fixed contact of the said switch is functionally connected with the newly introduced second disconnecting contact, the first output of which is connected to the second output the first break contact, and the second terminal has a terminal for connecting to the switching circuit of the electrical installation. .so n Checking +300, In the circuit off