SU583505A1 - Arrangement for monitoring three-phase network - Google Patents

Description

(54) DEVICE FOR THE CONTROL OF A THREE-PHASE NETWORK

VOLTAGE

The invention relates to electrical engineering and can be used to monitor the parameters of a multiphase voltage network.

Devices are known for monitoring a predetermined parameter of a three-phase voltage network flj,

It is also known a device for monitoring a three-phase voltage network containing a rectifier connected to a monitored network, the single-phase outputs of which are connected to the corresponding tapes of the transformer primary winding, between the ends of the winding and the transmitter of the rectifier include a high-frequency voltage source, and between the secondary winding transformer and actuating element included high-frequency voltage envelope form analyzer,

This device is a technical entity and the achieved result is closest to the invention. A disadvantage of the known device is that it does not allow controlling the changes in the level of the three-phase voltage.

The purpose of the invention is to increase the number of controlled parameters of a three-phase voltage network.

The goal is achieved by the fact that a device containing a rectifier connected to the controller of the network, the single-phase outputs of which are connected to the corresponding tapes of the transformer primary winding,

between the end of the winding of which and the general output of the rectifier the source of high-frequency voltage is switched on, and between the secondary winding of the transfs-mater and the actuating element

the high-frequency voltage envelope form analyzer is included, additionally equipped with a notch filter connected between the transformer secondary winding and the actuating element, and the high-frequency voltage source is designed as a relaxation self-oscillator, the control input of which is connected to the output of the rectifier. .

The drawing shows an electrical diagram of the device.

The device contains inputs 1-3 of controlled three-phase voltage,

three-phase rectifier 4, i-G-riiLiro transducer accumulates accumulator; element “8, reject fi rt 9,

The controlled voltage through ACODs 1--3 is supplied to a three-phase supply voltage 4 "Each voltage phase through the corresponding 5. The depleting rectifier diode is connected to one of the primary transformer taps 5, between the end of which and the common point of the straightening body, the relaxation auto-oscillator b is turned on The rectifier diode 4 opens sequentially in the order of phase alternation. The high-precision pulse current of the relaxation autogenerator 6 flows through a part of the gyurvich winding of the transformer 5 and the open rectifier diode 4. connecting the; m-e1x to pb2: phase grip occurs in steps: the atomic change of the transformation ratio and the level of the high-frequency matrix HS. the entrance to the torrent 7. The shape of the curvature; the high-frequency voltage depends on the symmetry and the order of the alternation of the phases of the voltage being monitored -: n If the phases are symmetric; -; post-irregularity of alternating rules: a,. then the duration of all C-upacies is the same and the increment of one sign of the amplitude of the high-frequency voltage is equal. If the amplitudes of the phase loads are not equal to one or more phases, the phase shift between the voltage Mti is violated, if the wrong sequence of phases, if the phase is not equal, then the phases are equal aivi ™ Parsing, while the analyzer 7 generates an output signal. I run the executive element 8,

Frequency of relaxation depends on the damage of the applied ic to the control input of the autogenerator b of the output eg; , -; rectifier m-4, At a nominal level; controlled three} phase phase, the oscillation frequency corresponds to the suppressor band; the frequency of the oscillator voltage 9. therefore, the oscillatory voltage from the SECONDARY winding trans

The formatter b does not arrive at the actuating element 8.

When you decrease or increase the level of the controlled: voltage, relative to the nominal values: the oscillation frequency, you are: outside the suppression filter suppression band. At the same time, the oscillating voltage from the secondary winding of the transformer 5 enters through a rector filter 9 and enters the execution element 8 and triggers the last. Thus, the device allows monitoring the symmetry and correctness of the phase alternation as well as the voltage level three-phase network.

p; acquisitions

A device for monitoring a three-phase power supply network, f containing a rectifier, connected to: a monitored network, an audiophile ;; which terminals are connected to the corresponding tapes of the primary winding of the transformer between the end of which winding and the common output of the rectifier included a source of high-frequency voltage, and between the secondary winding of the transformer and the actuating element, the analyzer fop; vsh is the envelope of the high-frequency voltage, which is due to the fact that, for the purpose of increasing: the number of controlled pairs etrov network t) eehfaznsgo voltage, it is further provided with rezhektsrniu vtorich. filter connected between the second winding of the transformer and the executive. element, - and the source of high-frequency voltage is made in the form of a relaxation self-oscillator, the control input which is connected to:

.Sources of information taken into account in the examination:

1 US Patent: 3681633, Cl, 317--4 7, i974,

2., Author's C1: Made the USSR f 515202 cl. H about; FI 3/24, 1975.

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