SU1379916A1 - Method of controlling a reversible thyristor converter - Google Patents

Abstract

The invention relates to the field of electrical engineering, in particular to the developing technique, and can be used to control reversible thyristor converters. The aim of the invention is to increase reliability and simplification. If at the time of unlocking the optothyristors 8.7 of the Back group, at least one of the optothyristors 6.9 of the Forward group is open, then the optothyristors 6 and 7 or 8 and 9 short the power supply 10 and interrupt the power supply of the impulse nodes. Fuse 1.1 is used to break the short circuit of the power source 10. Additional diodes 15,16 exclude the possibility of current flow through the primary windings of isolation transformers 2,3,4,5 with closed transistors 17,18. 2 Il. with S (L 00 sj

Description

The invention relates to electrical engineering, in particular to converter equipment, and can be used to control reversible thyristor converters.

The aim of the invention is to increase reliability and simplification.

FIG. a diagram of a device for controlling a reverse thyristor converter is presented; Fig. 2 is a diagram of a single channel of a phase shifting unit.

The device (FIG. 1) contains a reverse thyristor converter.

I, isolation transformers 2-5, electronic switches 6-9, power supply 10, fuse

I1, block 12 of separate operation of the thyristor groups, shunt diodes 13 and 14, additional diodes 15 and 16, also for the Forward and Back groups transistors 17 and 18 and the combined block 19 of phase shift, jyioT opto-thyristors are used as electric keys 6-9 and transistors 17 and 18 of the pn type are used.

I

The secondary windings of the isolation transformers 2-5 are connected to the control transitions of the thyristors of the reversing converter 1. Congda the primary windings of the separation transformers 2,3 and A, 5 are pairwise combined and connected respectively to the collectors of transistors 17 and 18, the emitters of which are combined, and the bases are connected to the outputs of the combined phase shifter unit 19. An optical thyristor 6–9 assembled a reversible bridge switch. The control unit of the optodistor LEDs 6.9 and 8.7 is connected in series and connected to the outputs of the unit 12 of separate operation of the thyristor groups. The primary windings of separation transformers 2.4 and 3.5 for the thyristor groups Forward and Back are interconnected and connected respectively to the cathodes of the additional diodes 15 and 16. The anodes of the latter are connected respectively to the outputs of the reversing bridge switch (combined cathode of the optothyristor 6 and the anode of the optothyristor 7, as well as the combined cathode of the optothyristor S and the anode of the optothyristor 9). The positive pole of the power supply 10 is connected via fuse 11 to

positive input of the reverse bridge switch (anodes of optothyristors 6 and 8). The negative pole of the power source 10 is connected directly to the negative input of the reversing bridge switch (cathodes of the optothyristors 7 and 9). Between the anodes of the additional diodes 15 and 16 and the emitters of the transistors 17 and 18 are connected, respectively, shunt diodes 13 and 14, conducting current in the opposite direction with respect to the transistors 17 and 18.

One channel of phase shifting unit 19 contains a clamp 20 for connecting a phase voltage, a clip 21 for connecting a reference voltage, a phase voltage filter 22 and a zero-indicator 23. A terminal 20 is connected to the first input of a zero-indicator 23 via a phase voltage filter 22, To the second input is connected to the kakim 21. Phase displacement unit 19 contains two channels similar to those indicated.

The device works in the following manner.

The transistors 17 and 18 are controlled by the program of the phase-shifter unit 19 for determining the timing of the control pulses. The phase shift unit compares the reference voltage of the phase voltage reference. At the moment of equality of these voltages, the phase shifting unit produces pulses arriving at the inputs of transistors 17 and 18.

Separate operation unit 12 of the thyristor groups generates signals permitting the supply of control pulses to the thyristors of the Forward and Back groups so that when the thyristors of one group (for example, Forward) are unlocked, the thyristors of the opposite group (Back) are locked. Moreover, the reverse program provides for switching off the state of all the thyristors of the converter 1 for the time of the dead time when switching the Forward and Back groups. The simultaneous supply of control pulses to the thyristors of the Forward and Back groups is unacceptable since it can cause a severe converter failure.

During the dead time, optotristors 6–9 are locked, and their control LEDs are de-energized. Impulses

Nodes assembled on transistors and separation transformers are not powered and control pulses are not provided.

When the thyristors are turned on, for example, the Forward group, the block 12 connects the power to the control LEDs of the optothyristors 6 and 9. The latter are unlocked and connect the power supply 10 to the pulse units of the Forward group along the circuit: the positive field of the source 10, the fuse 11, the optothyristor 6, additional diode 15, primary windings of isolation transformers 2 and 4, transistors 17 and 18, shunt diode 14, optotristor 9, negative pole of power supply 10. The impulse nodes of the group Back at this time are shunted by diode 14 and cannot receive a pi. During the dead time, the control LEDs are de-energized, the transistors of the pulse nodes are locked and cause the opto-thyristors 6 and 9 to be locked. The supply of control pulses to the Back group thyristors is similar. If at the time of unlocking the optothyristors 8 and 7 of the Back group, at least one of the Optothyristors 6 and 9 of the Forward group is open (the causes may be a failure of the block 12, a failure of the optothyristor transistor, etc.), then the optothyristors 6 and 7 or 8 and 9 short-circuits the power supply 10 and interrupts the power supply of the impulse nodes. The fuse I1 is used to break the short circuit of the power supply 10. Additional diodes 15 and 16 exclude the possibility of current flow through the primary windings of isolation transformers 2-5 with closed transistors 17 and 18.

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Formula H3o6ptiTeiiHH

A device for controlling rsner-cifBHbiM thyristor G1 transform (lnm, containing, according to the number of thyristors, separation transformers, cats, whose primary windings are connected to collectors of transistors, the emitters of which are combined, the beginnings of the primary windings of separation transformers are interconnected for each thyristor groups Forward and Back, two electronic key , the control inputs of which are connected to the outputs of the separate operation unit of the thyristor groups, and the phase shifting unit, characterized in that, in order to increase the reliability and simplified, two reverse shunt diodes were introduced, two additional diodes and two electronic keys, the control inputs of which are connected to the outputs of the separate operation unit of the thyristor groups, the ends of the primary windings of the isolation transformers for the same thyristors of the Forward and Back groups are connected to collectors common for the Forward and Next groups The back of the transistors, the bases of which are connected to the outputs of the phase-shifter, and the emitters are connected to the outputs of the reverse bridge via the corresponding reverse gaunt diodes. a switch assembled on the above four electronic switches, the inputs of which are intended to be connected to a power source, while the beginnings of the primary windings of the separator-HbDC transformers for the Forward and Back groups are connected through the corresponding additional diodes to the outputs of the reversible bridge switch.

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Claims (1)

Claim A device for controlling a reversible thyristor converter, containing, according to the number of thyristors, isolation transformers, the ends of the primary windings of which are connected to collectors of transistors whose emitters are combined, the beginnings of the primary windings of isolation transformers are combined for forward and backward thyristor groups, two electronic keys whose control inputs are connected with the outputs of the unit for separate operation of the thyristor groups, and the phase displacement unit, characterized in that, in order to increase the reliability and forgiveness, two reverse shunt diodes, two additional diodes and two electronic keys were introduced, the control inputs of which are connected to the outputs of the separate unit of the thyristor groups, and the ends of the primary windings of isolation transformers for the thyristors of the Forward and Back groups are connected to collectors common for the Forward and Back groups transistors whose bases are connected to the outputs of the phase-shifting unit, and the emitters are connected through the corresponding reverse shunt diodes to the outputs of the reversible bridge commutator an amplifier assembled on the above four electronic keys, the inputs of which are intended to be connected to a power source, while the start of the primary windings of the isolation transformers for the Forward and Back groups are connected through the corresponding additional diodes to the outputs of the reversible bridge switch. Fig 2