SU515202A1 - Device for monitoring a multiphase voltage network - Google Patents

Description

connected to the primary part of the transformer 2,

When alternating the phases connected to the load, a step change in the transformation coefficient and the level of the high-frequency voltage at the input of analyzer 4 occurs. The shape of the high-frequency voltage envelope has the form of a step; crooked. If the network is in good condition, the duration of all the steps is the same and with a certain order of phase alternation and increments of one sign, the amplitudes of the high-frequency voltage are equal. If there is no equality of the amplitudes of the phase voltages, a break of one or more phases, a change in the phase shift between the voltages, the equal duration of the steps is violated, and if the phases are incorrectly alternated, the amplitudes are equal. In this case, the analyzer 4 generates an output signal that triggers the actuator 5.

In this way, the device allows monitoring of the parameters of the multi-phase network.

The general electrical circuit of the proposed device is specified for the case of monitoring a six-phase voltage. The current flow from phases 6-11 flows through one of the pairs of rectifier diodes 1, the windings of the transformers, and the resistance 12 to a point with zero potential. At the same time, the output of the transformer 3 is closed through the small internal resistance of a pair of open diodes to a part of the primary winding of the transformer 2. The high-frequency voltage is transformed to the input of the envelope analyzer 4 containing amp; Chisel detector 13, differentiating unit 14, capacitive drive 15 and block 16 s two stable conditions (for example, a trigger). The analyzer output is connected to the input of the actuating element 5. A 17-control input of the block with two stable states. 18-input constant voltage feed ustriystva.

At the moment when the control device is turned on, control input 17 is given a signal, which sets block 16 to a certain steady state, which corresponds to the input from the output of the constant voltage circuit to the input of the actuating element 5.

The input of the actuating element 5 is de-energized either in the case of a tilting of a block with two stable states 16 or in the case of a loss of the supply voltage coming through the input 18.. The transformed voltage is used as the supply voltage.

monitored network or voltage from a & tonomic source.

The high-frequency voltage detected in the detector 13 and diffused in block 14 takes the form of a sequence of opposite-polarity pulses. The storage capacity of the storage device is charged from the power source of the device and is discharged upon receipt of opposite-polarity pulses.

to the control input. When the network is healthy, the interval between the discharging pulses is small and the capacitance does not have time to charge to a level sufficient to trip the trigger 16. The amplitude of the pulses, the post | to the other input of the trigger 16, with correct phase alternation, is also not large enough to overturn.

FIG. Figures 3, 4, 5 show voltage plots characterizing the operation of the circuit. FIG. 3 - diagrams of the envelope of high-frequency voltage at the input of the analyzer:

and - with all phases and correct

the alternation, the equality of the amplitudes of the phase voltages and the phase shift between voltages of a multiple of 60 °. (Y - in violation of the correctness of

do phases (incorrectly included 6 and 8). Z-when the amplitude of the voltage increases in phase 9 (relative to the point with zero potential).

and. - with decreasing voltage amplitude in phase 9.

(/ - with decreasing phase shift

between the voltages in phase 8 and 9. J - in phase break 7.

FIG. 4 - voltage diagrams at the output of the differentiating unit:

C / 8- C / 2-.

corresponds to C / 1/7-s; 4 Hz-s;

and

U9 3 10

five

ich2 and 6

I on. FIG. 5 - voltage plots at the output of capacitive storage 15: and IQ corresponds to | y; D u 2

 16- t; 4 / i7-t / 5UiQ-UeEn level of negative voltage,

sufficient to tilt the trigger 16.

Ej is the level of positive stress,

sufficient for tipping trigger 1.6.

As can be seen from fig.Ch, the amplitude of the negative impulses arriving at the trigger input, only with the wrong phase alternation is large enough for tilting | Vani. Positive pulses, restoring the circuit, or do not prb1 (go to the input of trigger 16 in protection devices, or periodically restore the circuit: b to the following alarm systems. In the first case, at the moment when the fault is detected, the actuator 5; turns off the network from the consumer, in the second executing element 5 goes to the pulse signaling until the fault is eliminated.

FIG. Figure 5 shows that the positive voltage supplied from the accumulator output; Tel 15 to the second input of the trigger 16 reaches a level sufficient for tilting, if the amplitude ratios are violated, the phase shift and the phase is broken.

Claims (2)

1. A device for monitoring a multiphase voltage network containing an exponent connected to a monitored network, to the output of which an actuating element is connected via a transformer. (characterized in that, in order to simplify the device, the single-phase outputs of the rectifier are connected to the corresponding tapes of the primary transformer, and between the common output of this rectifier and the end of the mentioned EMOTKH transformer a source is connected; low-frequency voltage transformer and executive element included high-frequency voltage envelope form analyzer. 2. The device according to claim 1, which is designed so that, in order to increase the number of monitored parameters, the high-frequency voltage envelope form analyzer is designed as an amplitude detector and a differentiating unit connected to one from the inputs of the block with two stable states and to the control input of a capacitive pump connected to another input of the above mentioned unit with two stable states, the output of which is connected to the input of the final element. P I to Fig.Z T gg Nl IL 7 T G GT s TG 7 G ( 21 / I7M7g