SU1203630A1 - Device for protection of self=excited voltage inverter - Google Patents

Abstract

The invention makes it possible to increase the reliability of a device for protecting an autonomous voltage inverter. Two differential amplifiers 15 and 16 and two threshold elements (PZ) 17 and 18 with inverse outputs are introduced into the device. When srabatshanie PE 17 and 18, the signal to the switching unit (BC) 12 will not pass, since the output element And 7 will not allow the signal. In this case, the second element AND 8 is activated, blocking all the output pulses of the control unit 9. If there is a possibility of commutation, then PE 17 and 18 are not triggered and a signal will be received on BC 12 permitting the BC to start operation. Additional threshold elements and differentiating amplifiers allow preemptive switching of the inverted inverter. 1 il. S (L 2 15 17 00 O) CO

Description

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The invention relates to electrical engineering and can be applied in devices for protecting valve converters.

The purpose of the invention is to increase the reliability of protection.

The drawing shows a diagram of a device for protecting an autonomous voltage inverter.

The device contains sensors 1 and 2 of current n about the number of shoulders of the inverter connected in series to the corresponding shoulders 3 and 4 of the inverter, and outputs connected via the corresponding threshold elements 5 and 6 to the corresponding inputs of the first element And 7 and the second element a And 8, the output of the control unit 9 connected to the corresponding input, the corresponding outputs of which are connected to the control 1-sh inputs of the shoulders 3 and 4 and the inverter and to the same inputs of the first 10 and second 11 Sh1K elements whose outputs are connected to the corresponding inputs of the blocks 12 switching connected to the shoulders of the inverter, shunted diodes 13 and 14 by the number of shoulders of the inverter, the first 15 and second 16 dM optical amplifiers, inputs connected to the outputs of the corresponding sensors 1 and 2 current, and outputs through the first 17 and second 18 additional threshold elements to the corresponding inputs of the first element And 7, the output of which is connected to other inputs of the first 10 and second 11 elements OR. The load I9 is connected to the output of the inverter, and the source 20 of the supply voltage is connected to the input of the inverter and to the supply input of the switching unit 12 switching.

The device works as follows.

During normal operation, the output of the first element And 7 of the signal em, since only one of the atchiki 1 or 2 currents has a signal.

When the inverter tilts simultaneously on two sensors of the shoulders of the inverter of one phase, the signals appear that exceed the thresholds of the threshold elements 5 and 6, as a result of which the corresponding inputs of the first element And 7 receive signals. If the signals from the first and second diff-4 Uren-1 of the dial-up amplifiers 15 and 16 are not hexa3630 .2

the thresholds of the first and second additional threshold elements 17 and 18 are extended, then the first element And 7 generates a signal allowing through

5 first and second elements OR 10 and 11 switching of inverter valves.

If, however, the first and second additional threshold elements are triggered, the signal to the switch 12 does not pass, since

the output of the first element And 7 there is no enabling signal. When the atom is activated, the second element is AND 8, which blocks all output pulses of block 9

15 controls

If there is a possibility of commutation, then additional first and second threshold elements 17 and

20 18 do not work, and the switching unit 12 receives a signal allowing the switching blocks to start working.

Additional threshold elements and differentiating amplifiers,

Printed in the circuit, allows you to prevent the switching of the inverted inverter.

Claims (1)

3Q claims A device for protection of a standalone voltage inverter, containing current sensors by the number of inverter arms, each of which is connected in series to the corresponding inverter arm, and output through the corresponding threshold element connected to the corresponding input of the first element And the corresponding input of the second element And, the output of the intended for connecting to the input of the control unit, the output of the first element AND is connected to one input of the first and second IDN elements, the outputs connected to the corresponding input The one of the co lution block and the other inputs of the first and second OR elements are designed to be connected to the corresponding outputs of the control unit, characterized in that, in order to increase the reliability of protection, it is equipped with first and second differential amplifiers  and the first and second additional threshold elements with inverse outputs, and the first element And is equipped with additional inputs, and. 35 40 31203630 the outputs of the current sensors are connected via the first and second additional to the first and second additional threshold elements of the differentiating amplifiers are respectively connected to the corresponding additional outputs of which correspond to the inputs of the first element I.