SU447649A1 - Device for controlling alternation and phase failure - Google Patents

Description

(54) DEVICE FOR CONTROL OF CHAIR AND SHEDDING PHASES

I

The invention is SUCCESSED to the field of automation of electric power systems and can be used when synchronizing generators and connecting three-phase consumers in electric power systems for various purposes and, in particular, in ship electric power systems.

The devices of similar purpose are known, the input windings of which are connected to: the phases of the monitored network, and the secondary ones to the inputs of rectangular pulse shapers, symmetric trigger, coincidence circuits, integrating elements and inverters.

However, such devices do not provide high accuracy: they give false signals when one of the phases is broken, or they do not allow controlling the phase failure immediately before connecting consumers or before synchronization.

To increase the reliability of control, the outputs of the square pulse drivers are connected to the three-input matching circuits, respectively, the second inputs of which are connected together and connected to one of the inputs of the symmetric trigger and the outputs of the two-input matching circuit of which are connected to the outputs of the square drivers; pulses,: also connected via two inverters with inputs of the second two-input matching circuit, connected via the output to the second input of the symmetric trigger. One of the outputs of the latter is connected to the inputs of three-input power failure circuits, the outputs of which, in turn, are connected through the integrating elements to the corresponding inputs of the inverters and simultaneously to the inputs

match schemes.

FIG. 1 is a schematic block diagram of the device described; in fig. 2 - time diagrams.

The device contains a three-phase input transformer 1, the primary windings of which are connected to three phases A, B and C of the controlled network, and the secondary windings to; two formers 2 and 3 rectangular

pulses, the outputs of which are connected to inverters 4 and 5, as well as to two-way coincidence circuits 6/7 If are re-inputs® 8 and 9. Inverters 4 and 5 are connected to other inputs of two-input coincidence circuits 6 and 7, whose outputs are connected With the trigger inputs Y of the trigger, Moreover, the output of the coincidence circuit 6 is also connected to the second inputs of the three-input circuits coinciding with scientific research institutes 8 and 9, the third inputs of which are connected to one of the outputs of the trigger Y. The outputs of the three-input coincidence circuits 8 and 9 through integrating elements 11 and 12 are connected respectively to the output nym inverters 13, 14 and simultaneously to dvuhvhodovry coincidence circuit 15. The output voltage elements are designated 2-15 in FIGS. 1 and 2 s, respectively, (AV) - voltage of shaper 2 and 3. When the device is switched on in the network, four variants of the circuit operation are possible: the first is when the voltage is U. c (t supplied to the input of the former 2 square-wave pulses, is ahead of the voltage V „,„ supplied to the input of the mold of 3 square pulses, which corresponds to the right order of phase alternation; the second variant corresponding to the reverse order of the phase alternation when the voltage Up | D (to) is ahead of the voltage bdb (BA) ° by phase A or B, and the fourth - phase B. The phase diagram in Fig. 2 corresponds to each variant. Let the device turn on (Diagram 1 in fig, at the time t .. 2), then the output The formers of 2 and 3 rectangular pulses are transmitted by signals 1 & and and Uo- These signals are inverted by J2.3, ... ... - - 4 and 5 and are fed to the input of a two-input coincidence circuit 7, and a signal appears at the output of a xusgor U, which sets the symmetric trigger 10 to the inhibit position. The inputs of the three-input coincidence circuits 8 and 9 are given the prohibition signal J lp - „„ ..... ...:: at time t of the two-input coincidence circuit 6, the signal appears Ug of coincidence of signals which sets the symmetric trigger of 10 to the position in which from three {input circuits In conjunction with B and 9, the prohibiting signal Y, ,,, BUT is removed simultaneously on the CX. The prohibit signal Y ,,. Thereafter, at time point to, the prohibition signal Ug is removed from circuits 8 and 9. but at the same time, the prohibition 2 signal appears at the input of the three-coincidence circuit 8, and at the input of the three-input coincidence circuit 9 all three prohibition signals are cleared; B, the output of the circuit 9 is the signal UQ, which through the integrating link 1O acts on the circuit inputs 14 and 15 and there is no voltage at their output. At the same time, U o signal appears at the output of the inverter 13, corresponding to the direct order of the phase alternation, Bo second variant (time diagram in Fig. 2) the circuit works similarly except for the time moment 1g "when (the signal appears output of the three-input coincidence circuit 8. As a result, the output signal is Ucc Vits at the output of the inverter 14, which corresponds to the inverse order of phase alternation.When phase A or B (temporal j diagram JE in FIG. 2) is used, one of the AB voltages (BA ) BB (AB), resulting in a signal and "two-input circuits , coincidence 7 sets the trigger 10 to the prohibit position and, therefore, the signal on the output of the coincidence circuits 8-pips and 9 are absent. A coincidence circuit 15 operates, at the output of which the signal Y is received, which corresponds to a phase loss. The input voltage (BA) Z (AB) timing diagram 1U in Fig. 2) turns out to be in phase and, thus, the inputs of the coincidence circuit § and 9 will be received alternately from the prohibition signals Y .. Q and and otriggera 10 and from the circuit coincidence 6, as a result, the signals Uo p, will be absent, and at the output about the circuit coincides 15 Vits signal also corresponding phase failure. In this way, the circuit signals the phase alternation and the termination of one of the phases, in which case the output signal appears on one of the three output channels, labeled Forward, Disconnected, and Reverse.

This signals can be used both for warning signaling and for control circuits of electric power systems and consumers.

PREED MET INVENTION

A device for controlling the alternation and phase wiring of three-phase networks, containing an input transformer, the primary windings of which are connected to the phases of the monitored network, and the secondary windings to the inputs of square pulse drivers, a symmetric trigger, matching circuits, integrating elements and inverters, which are in order to increase the reliability of the control, the outputs

6,

square pulse drivers are connected respectively to three-input coincidence circuits, the second inputs of which are connected together and connected to one of the inputs of a symmetric trigger and to the output of a two-input coincidence circuit whose inputs are connected to the outputs of a square pulse drivers connected also through two inverters with inputs of the second a two-input matching circuit connected to the output of the second input of a symmetric trigger, one of the outputs of which is connected to the inputs of the three-input matching circuits, you ode which, in turn, is connected via integrating elements .k respective inputs of inverters and simultaneously to the inputs of coincidence circuits.

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