DE1613631A1 - Trigger circuit for thyristor chains - Google Patents

Description

May 5th 1967

10848 - H / We

THE ENGLISH ELECTRIC COMPANY LIMITED, London W.C. /England

Trigger circuit for thyristor chains

The invention relates to a trigger circuit for simultaneous Ignition of one or more chain (s) of series-connected thyristors connected to a sweet voltage source.

The invention is particularly suitable for use in the use of series thyristor chains instead of high-voltage mercury-vapor converters in high-voltage direct current converters. In this case, all thyristors must essentially be applied simultaneously a Taatsteuerimpulses at the time of the desired power line be ignited, the pulse source for this ZUndimpuls is usually at or near earth potential. 9a some of the thyristors normally turn on

The devices for triggering these thyristors would have to be at a high voltage, for example 100 kV or more, which is significantly above ground potential Voltage be isolated; the cost of such isolation is substantial and decreases with increasing voltage to.

Oemäö of the invention is characterized by a trigger circuit by a number of Ira pulse transformers in cascade connection, in such a way * that the secondary winding of one Transformer connected to the primary winding of another, with each transistor of a group of the thyristors assigned 1st and each thyristor of a group a special one, old of its gate electrode and its wire has connected to it, the inductive coupled with the associated transform, as well as by control devices for applying an ignition pulse to the primary winding of one of the transfer batteries * in such a way that all thyristors are fired essentially simultaneously with one another.

The one with the gate electrode and the cathode of each thyristor lines connected and inductively coupled to the assigned pulse transformer can either use auxiliary winding · »on the pulse transformers connected in cascade,

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or be auxiliary windings on insulating transformers, their each is coupled to one of the cascaded transformers. In the trigger circuit gen & fi of the invention need the devices used to ignite the thyristors, i.e. in this case the impulse transformers in the insulation between their windings only for a fraction of that at the entire thyristor series connection chain to be designed to fall voltage. - *

In the following, embodiments of the invention are based on the drawing described; in this show

Flg. 1 shows a thyristor trigger assembly according to an embodiment of the invention;

2 shows a trigger circuit of exactly another embodiment before the invention.

In the circuit shown in Fig. 1, there is one out of nine In Series-connected thyristors existing strand between terminals 4 and 5, to which a high potential is applied. In parallel with the thyristors are voltage divider circuits, each of a resistor 6 and one Capacitor 7 exist and serve to equalize the voltage across the thyristors.

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Three pulse transformers 8, 9 and 10 are three each Thyristors assigned to the series. In detail, each of the pulse transformers has a core 11 with three auxiliary windings, which via current limiting resistors 12 between the respective gate and cathode electrodes of three transistors 3> lie. The pulse transformers are cascaded with each other switched; the pulse transformer 10 has a primary winding 10A, one end of which is directly connected to the terminal 5, and a secondary winding 10B connected to a Primary winding 9A of transformer 9 is connected; a secondary winding 9B of this transformer 9 is in turn with the primary winding 8A of the transformer 8 is connected.

The primary winding 10A is excited as a function of the actuation of a pulse generator 14 which has a light source 15 operated, the emitted light beam is focused on a photocell 17 by means of a lens. The output size of the The photocell is fed to a pulse amplifier 18 which excites the primary winding of the pulse transformer 10 accordingly. As transformers 8, 9 and 10 are cascaded with each other ■ are switched, the pulse pulses generated by the excitation of the primary winding 10A are applied essentially simultaneously to all thyristors in the strand. To this To ensure, however, the series impedance of each transformer should be very low, otherwise it will be considerable

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Total attenuation and time delay occur along the chain can. In practice, a satisfactorily low leakage reactance can be achieved by using the primary and secondary windings of the transformers as uniformly distributed toroidal windings on annular ferromagnets, i. Ferrite cores 11 executes * in such a way that the next but one successive turns of the winding through the primary winding, and the corresponding intervening linkseu are formed by the secondary winding, where, for all Windings of fine stranded stranded conductors are used to reduce their effective resistance at high frequencies.

For each of the transformers, the insulation between its various windings only needs for a break part of the between terminals 4 and 5 on the thyristor row applied voltage to be designed.

The pulse amplifier 18 can be on a considerably larger scale Potential lying at ground potential; the power for the operation of the pulse amplifier 18 can in principle one of the RC voltage divider circuits parallel to the thyristors can be removed. In practice, however, such a circuit arrangement could cause the voltage division to be excessive disturb; FIG. 2 therefore shows another method for supplying power to the pulse amplifier 18.

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161363T

In the circuit according to FIG. 2, the pulse amplifier 18 feeds Via a transformer 19, two chains 20, 21 of thyristors and pulse transformers; each of the two chains 20 and 21, respectively corresponds to the in Flg. 1 in the chain contained in the block outlined by dashed lines. The operating voltage for the pulse amplifier 18 is derived from the voltage applied to the thyristor chains Tension derived from two RC leather, each made of a resistor 23 and a capacitor 24; between the two RC-Oliedern is a current transformer 25. One Center tapping of the primary winding of this transformer 25 is with the junction between the two thyristor chains 20, 21 connected; the secondary winding of the transformer 25 supplies the operating voltage for the amplifier 18, through a Bridge rectifier 26, which is bridged old with a smoothing capacitor 27.

The DC supply voltage thus obtained depends on the alternating current component of the voltage applied to the thyristor chains away.

Through this "feeding of the thyristor chains from the middle" ("Center feeding") one achieves a reduction of the total attenuation and time delay of the tactile impulses for the end each chain lying transistors «compared with the one in Flg. shown "End-feeding".

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It should be emphasized that the invention does not go to details of the described switching arrangements is limited and that the exemplary embodiments described can be modified in many ways «without this. The scope of the invention would leave · Exemplary catfish can be very much as, as shown, three pulse transformers in cascade connection can be used, for example ten transformers, and each of these transformers can for example have about five auxiliary windings for a corresponding number of thyristors. Furthermore, each individual thyristor can through several thyristors lying parallel to one another are replaced, each such parallel group being controlled from an auxiliary winding; Furthermore, a number of Thyrletorkeiten can itself connected in parallel to each other. UkB to simplify the winding of the pulse transformers, each group can controlled by thyristors from auxiliary windings on an isolating transformer, which is connected to the secondary winding of the main pulse transformer is coupled.

Other methods of energizing the cascade are also used Pulse transformers can be used. For example, the photocell 17 can by a small, light-sensitive Thyristor can be replaced, which is triggered directly by the light beam. Alternatively, the coupling to earth can either consist of a single impulse transformer full of primary

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Secondary insulation, or on a chain of transformers ■ with suMbMuid less isolation from earth. Exist.

• If a chain of lepule transformers is used in this one In a way to connect from earth, you reduce the insulation costs, however, BpentHmgwteiler-Sehalfittel »i.e. Viderstaods-Xondensator-eohftltuzicen, »wipe the FrIeXr- and flitasMtMransohinesen Any transformers required, including the Compensate for stresses occurring above the insulation.

In both of these mentioned procedures, the use is made a legttlfeffcers' can be dispensed with if the general testbsv. the achievement is transmitted from earth.

- patent application-

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Claims (1)

Patent claims © 1.) Trigger circuit for the simultaneous ignition of a chain of a voltage source in series! Thyristors, marked with an® Ansah! of impulse transformers (8 to 10, Fig. 1) in cascade © risöhaltimg _s such that each time a transformer with the primary winding © isi @ e aad @ r @ a ^ ®Th \ mämn "with each transistor © Ines · feapps des »Sfisrasfeoffea (3) is assigned, and in each case j @ <ä © s> © Jurist ©! ⁵ ®ln © s » ®έϊά®φ® © Ine special®, mf.te of his Tor @ lekfe? O € s wiu © © teas * l bound line (12) aiafKrelsfe * dl® isdukfeiir Mt« te submissive Traisforaato ^ gskoppslfe lnt _s a © tj £ © by control devices (14 to 18) for the application of the ignition pulse to the primary winding (10A) of one of the transistors (10), so that all thyristors are ignited together essentially on the glider side. Trig / *> circuit according to claim 1, thereby geke η η - 2. shows that the one with the gate electrode and the Cathode of each of the transistors connected lines auxiliary winding who are impulses & formers. - 3. Trigger circuit according to claim 1 »dadurefo & © ■ Jc ® ■ aa - 00Si85 / 0502, 161363t jl - 10 - ti. shows that between the gate electrode and the cathode of each of the transistor transistors lying lines »lt den associated Xapulstransforaatoren About Isollertransfurisatoren are connected. *. Are Trigger circuit according to one or more ά "ν claims 1 to 3, characterized in that the lepuls-.tr & nsf oreatoren toroidföraige iferromagnet-Rlngkerne (11)" on w @ lehen the PrimMr- and 3ekundlr9flcklungen gleiehfttesig distributed so that in each case the next but successive turns of the windings are formed by the pre-winding and the corresponding secondary winding by the secondary winding 5. Trigger circuit according to one or more of claims 1 to 4> characterized by the fact that the control device (17, 18) is used to generate the pressure pulse Light radiation (15, 16) is actuated from a remote location. 6. Trlggerschaltung according to claim 5 » characterized in that the control device has a pulse amplifier (18) old a photo cell (17) or a» light-sensitive thyristor « 009885/0502 -H- 7. Ftrlggeraenaltung according to claim 5 or 6, characterized in that dtf the operating voltage for the lepuleverstKrksr (l8) ai »the voltage source (%, 5) derived is connected to which dl · fhyristor chain did « 8. Trigger activation neon one or more of the ÄneprUohe 1t> ie * 4 «by the fact that the control device« in the lapulasenarfttor «it« in «r KaakadeBlcetfce of iBpuletraneforeatejpeii, which are spelat from Srdpotmtiel bar e *, having;· 9. Triggerechaltung according to one or «eftirer" of Ansprtiehe 1 Me 8, characterized ge characterizing sei.ebnet "AaB Multiple chains (20, TO Flg. S) are of eeaabalteten in grater fhjrietoren in Kaskftdeneohaltung at a iuSeren Spemunceyielle and that gleiohseltigen sur f ^ tnAang continuous Shyrl «t®f $ n a geoMinaaae Steuervorriohtune (l8 _f 19) let" dene Zündiepulee deliver to the individual TbyristorlGetten "! ordered Iwpuletransfora & toren. 10. Trigger switching according to "iE" sa or several of the Claims 1 to % characterized in that each thyrietor chain ufwelet both series and parallel connections of thyrietorsa. I BAD ORIGINAL 11. Trlggereehaltung according to claim 10, characterized in that each pulse transformer with a look! of parallel groups coupled via an auxiliary transformer which has a winding coupled to the associated pulse transformer and a number of further windings coupled with the thyristors of the parallel groups . 0 0 9885/0502 Blank page