SU1492429A1 - Device for control of power transformer - Google Patents

Abstract

The invention relates to the field of converter technology and can be used to reliably turn on thyristors in discontinuous current modes in installations for various purposes. The aim of the invention is to increase the reliability of the thyristor connection in the mode of intermittent currents and efficiency. If the trigger 1 is in a state where the transistors 5 and 7 are closed, the charge on the capacitors 13 and 15 starts, and a pulse appears on the control electrode of the thyristor 27, because Photo-thyristor optocoupler 23 is open. After unlocking the thyristor 27, the photo-thyristor of the optocoupler 23 is closed, which causes a breakdown in the generation of control pulses. In the absence of optocouplers 23 and 24, which play the role of thyristor state sensors 26,27, the control electrodes of thyristors 26 and 27 receive a burst of pulses, the duration of which depends on the time constant of the circuits, resistor 8 - capacitor 12 and resistor 9 - capacitor 13. After unlocking the transistor 17 on the resistor 19, a pulse appears, which switches the trigger 1, and a control pulse appears on the thyristor 26. Further work proceeds according to the described algorithm. 2 Il.

Description

Phage

Isobr cHHt; relates to converter equipment and can be used to reliably turn on thyristor in discontinuous current modes in installations of personal assignment.

The purpose of the invention is to ensure the reliability of the inclusion of thyristors in the mode of intermittent currents at the lowest losses in the control transition. Fig. 1 is a schematic diagram of the device; Fig. 2 shows voltage diagrams for individual circuit elements.

The device contains a trigger 1, the outputs of which through the Zener diodes 2 and 3 are connected to the installation inputs of the time of the driving circuits made on transistors 4-7, resistors 8-11 and capacitors 12-15, the outputs of KS-circuits 8-12, 9-13 through odnrpere - the input transistors 16 and 17 and the resistors 18 and 19 are connected to the trigger inputs, and the outputs of the KS circuits 10-14 and 11-15 through the single junction transistors 20 and 21, in the circuit of which the receiving parts of the optocouplers 22 and 23 are connected in series to the primary windings of pulse transformers 24 and 25, the secondary windings of which are connected with the thyristors 26 and 27, parallel to the thyristors, through the limiting resistors, the radiating parts of the optocouplers 22 and 23 are connected,

The device works as follows.

With the help of variable resistors 8 and 9, the required duration of the control pulse bursts is set, and with the help of resistors 10 and 11, the frequency of the pulses in the batch is set.

Assuming that the trigger is in such a state that the transistors 5 and 7 are closed, then the charge of the capacitors 13 and 15 (FIG. 2) starts and a pulse appears on the control electrode of the thyristor, since the photothyristor of the optocoupler 23 is opened by the presence of a positive voltage at the thyristor anode 27. After unlocking the thyristor 27, the voltage at its anode becomes close to zero and the optocoupler closes, causing a breakdown in the generation of control pulses. In the case of the thyristor 27 being locked (in the discontinuous current mode), a high positive voltage again appears at its anode,

Typical photo thyristor optocoupler 23 drops sharply and a pulse appears on the control electrode of the thyristor. nf) ii in the absence of an opto, which plays the role of a thyristor state sensor, a pulse train would arrive at the control electrode of the thyristor, the duration of which is due to constant time 1 and RC circuit 9, 13. After unlocking transistor 17 on resistor 19, a pulse that triggers trigger 1 (FIG. 2), and a control pulse appears on the thyristor 26. Further operation of this part of the circuit is performed using the same algorithm.

The proposed device provides reliable switching on of the thyristor in the mode of intermittent currents, which ensures a case-sustained load operation. At the same time, a reliable switching on of the thyristor is ensured with minimal losses in the control junction, which prevents the thyristor from overheating.

Claims (1)

Invention Formula five 0 five 0 five A device for controlling the power thyristor, containing a symmetric trigger, the outputs of which are connected through the zener diodes to the installation inputs of two time master circuits, the power inputs of which are connected to the positive output of the power source and the common point of the device, and the time outputs of the master circuits are connected. with corresponding mounting inputs of a symmetric trigger, and two pulse transformers, the secondary windings of which through diodes are designed to connect to the control electrodes of the corresponding power thyristors, characterized in that, in order to increase the reliability of the thyristors on in the discontinuous current mode and efficiency, two formers are introduced bursts of pulses, two thyristor optocouplers and two resistors, each of the drivers of the bursts of pulses made in the form of a KS circuit with an adjustable resistor, connected in parallel to the capacitor, which is connected to the junction of the collector -:) the mitter of the transistor, the base of which is through a current-limiting resistor connected to the anode according to: tvu 1.) sheg, zener diode, connection point od1P1X of the capacitor leads and adjustable resistor of the KC circuit connected to the emitter of the single junction transistor, the first base of which is connected to one output of the primary winding of the corresponding pulse transformer and the cathode of the diode, second base - the cathode of the photothyristor of the corresponding thyristor optocoupler, the LED of which through the corresponding resis lup is nice :); / t nod - n, - - raplplno gootlet (i wisely synov) to the thyristor, other control signals, No., 1X resistors of the KS circuit and photodiristor photo thyristor capacitors, are connected to the positive power supply of the optocoupler, - chains, diodes anodes and other conclusions of the primary windings of pulse transformers - with a common point of the device. Editor N. Tupitsa Compiled by A. Kiselev Tehred L. Serdyukova Proofreader O. Tsiple Order 3889 / 5D Circulation 646 RFILI of the State Committee for Inventions and Discoveries at the State Committee on Science and Technology of the USSR 113035, Moscow, Zh-35, Raushsk nab., D / 5 FIG. g Subscription