SU1408494A1 - Protection device for thyristor converter - Google Patents

Abstract

The invention relates to electrical engineering and is intended to monitor the state of series-connected thyristors of a converter. The purpose of the invention is to increase the reliability and expand the field of use. The device contains a saturation throttle 5 connected in series with the thyristor 1, which is bridged by RC circuits 2 and diode 3 and is locked by node 4. Two series-connected RS are connected to the terminals of the secondary windings of b droplets through a resistor 7 trigger 10, 13 and two T-flip-flops 11 and 12. The direct outputs of the triggers 12 and 13 are connected to the input of the element And, the signal from the output of which will follow to the sending system 15. When the thyristor 1 is locked, the choke 5 is re-magnetized; on the secondary winding 6, direct and reverse polarity pulses are formed which do not cause the device to operate. In the event that the thyristor (or part of the thyristor) does not restore the direct resistance, then a third pulse is formed on the winding, which is the second for the counter on T-flip-flops 11 and 12 and switches it to state 1. The first pulse is Vision 1 was switched by the second RS flip-flop 13. At the inputs of the And 14-element. Two signals are received, with the result that the system 15 is blocked. 2 Il. with (Q e

Description

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The invention relates to electrical engineering and can be applied in semiconductor converter protection devices designed to control the voltage in electric rolling stock control systems.

The purpose of the invention is to increase the reliability and expansion of the field of use,

Fig. 1 is a schematic diagram of the device; figure 2 - timing diagrams.

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In figure 2 indicated: Ug, Ug, U,

fi 1g f3. i in1 G4 in the diagram of voltages on the corresponding

elements.

The device includes a power thyristor shunted by KC-circuits 2 and a diode 3, switching node

4dl thyristor off, choke

5 saturation in the circuit of the thyristor 1, the secondary winding 6 of which is connected to the input of the voltage pulse limiter, consisting of a resistor 7 and two oppositely connected Zener diodes 8 and 9, and the anode of the Zener diode

8 (first terminal) is connected to input S of the first RS flip-flop 10 and to the R-inputs of T-flip-flops 11 and 12, which form the pulse counter, the cathode of the Zener diode 9 (second limiter terminal) is connected to the input R of flip-flop 10 and the counting input of trigger 11 The RS inputs of the flip-flop 13 are connected to the direct and inverse outputs of the flip-flop 10. The direct outputs of the flip-flops 13 and 2 are connected to the element 14, the signal from the output of which is fed to the input of the control system 15.

The device works as follows.

 When the thyristor 1 is turned on by a reverse current, the saturation choke 5 is re-magnetized, a voltage pulse is generated on the secondary winding 6, which through the Zener diode 8 is fed to the S input of the RS flip-flop 10, switching its state 1 to the reset input T of the flip-flops 1 and 12 which go to state O. RS-flip-flop 13 also switches to state O (time t in Fig. 2). When voltage is restored on the thyristor 1 at the end of the switching interval, when diode 3 is locked, through which the current of the switching node 4 flows, to the winding

The keg of the throttle appears a pulse of another polarity, which through the Zener diode 9 is applied to the RS-flip-flop 10 and T-flip-flop 11. The RS-flip-flop 10 switches, resulting in the RS-flip-flop 13 going into state 1, If the voltage of one of the devices goes into the open state (the thyristor 1 does not restore the direct resistance), then a voltage pulse of the previous polarity, which goes to the counting input T of the flip-flop P, is created on the winding of the throttles, as a result of which the output T of the flip-flop 12 according to logic 1, input to ementa 14, the other input of which is fed with the signal output RS-flip-flop 13. The output signal of AND 14 blocks the control system 15.

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Claims (1)

Invention Formula A device for protecting a thyristor converter equipped with a control system containing a dros. - :, saturation cell, intended to be connected to the –circuit in series with the thyristor of the converter, RC circuit and diode, intended to be connected in parallel to the thyristor of the converter, the secondary winding of the end connection is connected to the input of the voltage limiter consisting of a resistor and two zener diodes, t is characterized by the fact that, in order to increase the reliability and expand the field of use, two RS-flip-flops were introduced, the AND element and the pulse counter, performed on two T-triggers, with one pin of the limiting resistor The voltage is used as the input of the voltage limiter, and the other output is connected to the cathode of the first and second Zener diodes, while the anode of the first Zener diode is used as the first output of the voltage limiter and connected to the S input of the first RS trigger and the reset input of the counter, the cathode of the second Zener diode is used as the second output of the voltage limiter and is connected to the R-input of the first RS-flip-flop and the counting input of the counter; the direct and inverse outputs of the first RS-flip-flop are connected respectively to the R- and S-inputs 31408А9А4 The second RS flip-flop, the output of which is output to the counter, and the output of element 1 is connected to the first input of the element, is started to be connected to the input I, the second input of which is connected to the control system.