SU1292099A1 - Device for checking phase alternation in three-phase network - Google Patents

Abstract

This invention relates to electrical engineering, in particular, to relay protection. The purpose of the invention is to increase reliability by simplifying the interface between the phase rotation control unit and the actuating unit. When the network phase alternates, the duty cycle of the pulses coming from the outputs of the flip-flops 4-6 to the inputs of the circuit 7 for detecting most of the three signals is 3, the output of the circuit 7 will be a logical O coming to the input of the execution unit 12. When the reverse phase sequence of the network, the duty cycle of the pulses coming from the outputs of the flip-flops 4-6 to the inputs of the circuit 7 is 1.5, the output of the circuit 7 will be logical 1 coming to the input of the execution unit 12. 3 Il. f (L I Figure 1 I

Description

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11292099

The invention relates to electrical engineering and can be used in systems for monitoring and protecting three-phase loads from incorrect alternation of network phases.

The purpose of the invention is to provide control of both direct and reverse phase alternation with two stable logical states and simplification of the interface with an additional device.

1 shows a functional diagram of the device; Figures 2 and 3 are timing diagrams explaining the principle of operation of the device (direct and reverse phase rotation, respectively),

The device contains zero-level detectors 1–3, asynchronous R-S triggers 4–6, circuit 7 for detecting most of the three input signals, assembled on elements AND-HE 8-11 and executive unit 12..

The device works as follows.

Zero-level detectors 1–3 are allocated and zero-level sinusoidal voltage levels are converted into a pulse train. The pulses from the outputs of detectors 1-3 of the zero level are fed to the inputs of asynchronous R-S triggers 4-6, switching them. Timing diagrams of voltages at the inputs and pulses at

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Comrades and NOT-8-11 of the scheme 7 for detecting the majority of the three signaling signals are shown in diagrams U10, UN, U12, U13 (Fig. 2), respectively.

In the case of reverse phase network interlacing, the pulse width of impulses coming from the outputs of the flip-flops 4-6 to the inputs of circuit 7 for detecting most of the three signals is 1.5. At any time, one of the inputs for circuit 7 for detecting most of the three signals is logical. and on the two pipe inputs of the circuit 7, the detection of most of the three signals — logical I, Time diagrams of voltages at the outputs of the flip-flops 4–6 are shown in the diagrams U7 and U8, U9 (FIG. 3), respectively. At the output of circuit 7 for detecting most of the three signals, there is a logical 1 arriving at the input of the actuator 12, timing diagrams at the outputs of the AND-NE 8-11 elements of circuit 7 for detecting most of the three signals are shown in diagrams U10, U11, U12, U13 (fig.Z), respectively.

When monitoring the forward and reverse phase interlacing of the network, the proposed device does not require additional output signal processing to interface with the actuator,

The use of the proposed mouth-.

the outputs of the detectors 1-3 of the zero level in the control and protection systems with direct and reverse alternation of three-phase loads from the wrong phase of the network are shown in diagrams

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When alternating the phases of the network, the duty cycle of the pulses coming from the outputs of the flip-flops 4-6 to the inputs of the circuit 7 for detecting most of the three signals is 3. At any time, one of the inputs for the circuit 7 for detecting the majority of the three signals has a logical 1, and on the other two inputs of circuit 7, the detection of most of the three signals is logical. O. Time diagrams of voltages at the outputs of the trigger 4-6 are depicted in diagrams U7, U8, U9 (Fig. 2), respectively. At the output of the detection circuit 7 most of the three signals have a logical o arriving at the input of the actuator 12. Timing diagrams at the outputs of the element 40

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The alternation of the network phases in comparison with the known one allows to simplify the interface with the actuating device, reduce the number of used No. 1 elements and reduce the cost of the component elements by 20%,

The device can be made in microelectronic performance, since it does not contain reactive and adjustable elements. The operability of the device does not depend on the change in the network frequency and the phase skew of the network,

Formula

the invention

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A phase rotation monitoring device in a three-phase network, comprising three zero-level detectors and an execution unit, characterized in that, in order to

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Comrades and NOT-8-11 of the scheme 7 for detecting the majority of the three signaling signals are shown in diagrams U10, UN, U12, U13 (Fig. 2), respectively.

In the case of reverse phase network interlacing, the pulse width of impulses coming from the outputs of the flip-flops 4-6 to the inputs of circuit 7 for detecting most of the three signals is 1.5. At any time, one of the inputs for circuit 7 for detecting most of the three signals is logical. , and on the two pipe inputs of the circuit 7, the detection of most of the three signals — logical I, Time diagrams of voltages at the outputs of the flip-flops 4–6 are shown in diagrams U7 and U8, U9 (FIG. 3), respectively. At the output of circuit 7 for detecting most of the three signals, there is a logical 1 arriving at the input of the actuator 12, timing diagrams at the outputs of the AND-NE 8-11 elements of circuit 7 detecting most of the three signals are shown in diagrams U10, U11, U12 , U13 (fig. 3), respectively.

When monitoring the forward and reverse phase interlacing of the network, the proposed device does not require additional output signal processing to interface with the actuator,

The use of the proposed mouth-.

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The alternation of the network phases in comparison with the known one allows to simplify the interface with the actuating device, reduce the number of used No. 1 elements and reduce the cost of the component elements by 20%,

The device can be made in the world electronic version, since it does not contain reactive and adjustable elements. The operability of the device does not depend on the change in the network frequency and the phase skew of the network,

Formula

the invention

55

A phase sequence monitoring device in a three-phase network, comprising three zero-level detectors and an executive unit, characterized in that, in order to increase reliability by simplifying the interface between the phase-rotation control unit and the executive unit, it is additionally equipped with three asynchronous triggers and a majority detection circuit of the three signals, where the output of the first zero-level detector is connected to the input S of the first trigger and the input R of the third trigger, the output of the second zero-level detector is connected to the input S i th R flip-flop and the input of the first flip-flop, the output of the third zero crossing detector is connected

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with input S of the third flip-flop and input R of the second flip-flop, output Q of the first flip-flop is connected to the first input of the detection circuit of most of the 5 three input signals, output Q of the second flip-flop is connected to the second input of the detection circuit of most of the three input signals, output Q the third trigger is connected to the third one; most of the three input signals are detected; the output of the detection circuit of most of the three input signals is connected to the input of the execution unit.

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Compiled by V.Orlov Editor Oh, Golovach Tekhred L.Serdyukova Proofreader V. But ha

Order 280/54 Circulation. 619Subscribe

VNIIPI USSR State Committee

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

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

Claims (1)

Claim Alternation Control 35 phases in a three-phase network, containing three zero-level detectors and an actuator unit, characterized in that, in order to improve reliability by simplifying the interfacing of the phase rotation control unit with the actuator unit. · It is additionally equipped with three asynchronous triggers and a detection circuit for most of the three signals, the output of the first zero level detector connected to the input S of the first trigger and the input R of the third trigger, the output of the second zero level detector connected to the input S of the second trigger and the input R of the first trigger, the output of the third zero level detector is connected x 1292099 4 with the input S of the third trigger and the input R of the second trigger, the output Q of the first trigger is connected to the first input of the detection circuit of most of 5 three input signals, the output Q of the second trigger is connected to the second input of the detection circuit of most of the three input signals, the output Q of the third trigger is connected to the third By the input of the detection circuit of most of the three input signals, the output of the detection circuit of most of the three input signals is connected to the input of the executive unit. 111 U8 SH7D SH7L SH7L V7777A J 1 — ESSl ........ VTTTZb ........ U2777L. V77777 \ 47772 ^ 7777777 ^. ^ 777777 U7777L 477777λ 77772 J VZZZTTX 77777 V77777 3 ESSI ESSL U9 ju U11 ^ Ϊ77777λ M 7ZZZZ ^ ZZ2 ^ 2Z2ZZ ^^ ZZZZZZZZZZZZZ2ZL Fig.Z