SU1520621A1 - Device for protection of three-phase load from damages in ac circuits - Google Patents

Abstract

The invention relates to electrical engineering and is intended for use in relay protection and automation systems. The purpose of the invention is to simplify, reduce power consumption and vibration of the contacts of an actuator by reducing the variable component of its operating magnetic flux. During normal operation of the monitored network and the correct phase rotation at the input terminals 12, 13, 14 of the device in the order of 12-13-14, after supplying the trigger pulse to the output 16, the thyristors 1, 2, 3 are alternately opened, supplying the windings 11, 17, 18 executive body 10. The latter is included, indicating a normal operation of the network. When the phase or the neutral wire of the monitored network is disconnected, as well as if the phase sequence is incorrect at the input terminals 12, 13, 14 of the device in the order of 12-14-13, the alternating switching on of the thyristors 1, 2, 3 is interrupted, all thyristors are closed, the actuator 10 turns on , signaling abnormal operation of the monitored network. 1 il.

Description

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The invention relates to electrical engineering and is intended for use in relay protection and automation systems.

The purpose of the invention is to simplify, reduce energy consumption and reduce the vibration of the contacts of an -executive organ by reducing the variable component of its operating magnetic flux,

The drawing shows a diagram of the device.

The device for protection of a three-phase load against alternation and phase failure contains three thyristors 1–3, three Zener diodes 4–6, three resistors 7–9, the actuator is a relay 10 with the first winding 11, three input terminals 12–14 for connecting to phases a monitored network; a neutral output 15 for connecting to the neutral network wire; and a trigger output 16 for connecting to the output of the control unit. Thyristor anodes 1–3 are each connected to the corresponding input terminal 12–14, the cathode of the first thyristor 1 through the serially connected cathode – anode of the first zener diode 4 and the first resistor 7 is connected to the control electrode of the second thyristor 2, the cathode of which through the serially connected cathode the anode of the second Zener diode 5 and the second resistor 8 is connected to the control electrode of the third thyristor 3, whose cathode. through the cathode-anode of the third Zener diode 6 connected in series and the third resistor 9 is connected to the control elec genus first thyristor 1 connected to the terminal 16 starts. Executive body 10 is provided with a second 17 and third 18 windings. The initial terminals of the windings 11, 17 and 18 are each connected to the cathode of the corresponding thyristor 1-3, and the terminal terminals of all the windings 11, 17 and 18 are connected to the zero terminal 15,

The device works as follows.

During normal operation of the monitored network and the correct phase rotation at the input terminals 12-14 of the device in the order of 12-13-14, after the start impulse is applied to the output 16, the thyristors are alternately opened, energizing the windings 11, 17 and 18 of the actuator 10, the last one.

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it is reported that the network is operating normally,

When the phase or ground wire of the monitored network is broken, or if the phase sequence at the input pins 12-14 of the device is wrong in the order of 12-14-13, the alternate 1 turn-off of thyristors 1-3 is interrupted, all thyristors are closed, the actuator 10 is turned off, signaling abnormal operation of the controlled network.

The reduction of the vibration of the actuator contacts in the proposed device is ensured by the constant magnetic flux of the relay, since when the flux induced by one winding decreases, the flux induced by the other winding simultaneously increases, and the sum of the fluxes of the three windings of the relay remains almost constant.

Claims (1)

Invention Formula The device to protect the three-phase load from alternating and alternating phase failure, containing three thyristors, three zener diodes, three resistors, is-. a complementary relay body with the first winding, three input terminals for connecting to the phases of the monitored network, a zero terminal for connecting to the neutral wire of the network and a trigger terminal for connecting to the output of the control unit, each of the thyristor anodes connected to the corresponding input terminal of the first thyristor the cathode-anode of the first zener diode connected in series and the first resistor are connected to the control electrode of the second thyristor, the cathode of which through the cathode-anode of the second stably connected The orthron and the second resistor are connected to the control electrode of the third thyristor, the cathode of which is connected through series-connected. the cathode-anode of the third zener diode and the third resistor are connected to the control electrode of the first thyristor connected to the start terminal, which, in order to simplify, reduce power consumption and reduce the vibration of the contacts of the executive body by reducing the variable component of its working magnetic flux , execute5152062 The body-relay is supplied with the second and the corresponding thyristor, and the third winding is the end, the initial conclusions of all the windings are connected to the windings, each connected to the cathode with a zero output.