SU546067A1 - Device for generating thyristor control pulses - Google Patents

Description

a torrent by either continuing to supply control and multiplexes to all power thyristors of the shoulder, or simultaneously removing control signals from all power thyristors of the shoulder in the proposed device, the collectors of the last transistors of all cascades are interconnected by complementary diodes in a ring pattern.

FIG. 1 shows a schematic diagram of the device described; in fig. 2 is another possible embodiment of its implementation.

The diode / is intended for charging the capacitor 2. In addition, the diodes / and 5 exclude the mutual influence of the sources on each other. The secondary winding of any of the pulse transformers 4, 5, 6 is designed to control parallel-connected power thyristors of one row of the shoulder of the conversion unit. Diodes 7, 8, 9 are connected in a ring circuit and connect collector electrodes of transistors 10, 11, 12. Through a ballast resistor 13, a signal lamp 14 is connected to the sources, which is lit when the fuse 15 is working properly. tension and source 17 of constant voltage, and the amplitude of the voltage source 16 is greater than the magnitude of the source 17.

The principle of operation of the proposed device for shaping im. pulses of control in the nominal mode is as follows. In the positive half-period of the source voltage 16 (charge of the capacitor 2 from this source occurs through the diode /. In the next half-period of the voltage of the source 16, control bases from the preliminary stage, not In the diagram of Fig. 1. At the time of opening of the transistors 10, 11, 12, the discharge of the capacitor 2 occurs through the primary windings of the pulse transformers 4, 5, 6 and the transistors 10, 11, 12. In this case, in the control junctions of the power thyristors the shoulders are formed by falling impulses. with an amplitude of several times the largest static control current of the thyristor data. When the voltage 1 to the capacitor 2 when it is discharged is exhausted with the voltage of the source 17, the current from the source through the primary windings of the pulsed transformers 4, 5, 6 until the switching point of the transiutors. The amplitude of the control pulses at this time is slightly higher than the highest static control current of the thyristors. In the next voltage semipad, charge 7- occurs again: it, capacitor 2, and so on.

In emergency mode, the circuit in FIG. 1 works as follows. At the moment when a single transistor breaks down, a cyclone & is created at the output of a collector junction, such as a transistor, //. h (“Plus source 17, fuse 15, primary windings of transformers 4, 5, 6, diodes 8 and 9,

the transistor //, "minus source / 7), and after saturating the cores, the transformer 4, 5, 6 simultaneously stops the supply of control pulses to all the power tigrators of the shoulder. Mode K. h. in these chains

will take place. before the moment of burnout

fusible. insert fuse 15, after

which should go off the signal lamp 14.

In case of failure of any other.

transistor with a shorting collector junction or two transistors simultaneously processes in the circuit of the proposed device will develop in a similar way. In the TOIM case, if one. Of the transistors,

for example, // a collector-emitter has broken out, then the circuit from source 17 and capacitor 2 through the primary winding of the trap: Mator 5 is closed through diode 7 and transistor 10 or through diodes 7 and

5 and the transistor 12. As a consequence, the control pulses continue to flow to the power thyristors of the entire arm. The transistors 10 and 12 operate in this mode with some overload, but the circuit is still operable.

It is possible to connect the source 16 via the diode / and the fuse 18 to the collector of one of the transistors (Fig. 2).

There are also two sources in the circuit: the amplitude of the voltage of the source 16 of the alternating current is greater than the voltage of the source 17 of the direct current. Diode / in. Connected between the source 1/5 and the collector electrode of the transistor 10 and. intended for charge

the capacitor 2 in the positive half-period for the source 16.

This scheme works according to the following principle. At the moment when the transistors 10, 11, 12 are closed, the capacitor 2 is charged from the source 16 through the diodes /, 8, 9 and the primary windings of the pulsed transformers 4, 5, 6, and the charge current of the capacitor 2 causes a reversal ser.dechni1KOV 4, 5, 6. At the moment of opening the transistor, W, 11, 1,2, the capacitor 2 is discharged through the primary windings of transformers 4, 5, 6 and transistors 10, 11, 12. When the voltage is on the capacitor 2 is compared with the voltage of the source 17, it becomes possible for the current to flow from the source 17 through the first: windings rmatorov 4, 5, 6. The proposed device provides increased reliability preobrazavatelnogo device of bespechiva-protection in the breakdown of transistors.

Claims (3)

1.A. A. Sakovich, et al. "Application of Controlled Silicon Valves (thyristor) In the control circuits of static frequency converters, the journal Elektrokhestno, 1964, No. 7. 2. Avt. swith USSR № 217497, M. Kl. H 02 M 1/02. 1968. 3. Magazine “VVS-Nachrichten, 1968, N 3, pp. 125-126, fig. 5, 7 (prototype). 15