SU1679583A1 - Device for three-phase thyristor converter controlling - Google Patents

Abstract

The invention relates to converter technology, in particular, to thyristor converter control systems and can be used to control thyristor rectifiers. The aim of the invention is to stabilize the output pulse parameters. This goal is achieved by the fact that control pulses are generated in the impulse / field windings. transformer 11 that feeds dosing current pulses from the time of the driving capacitor 8 Three-channel phase distribution of output pulses is carried out by thyristor keys 17 included in the secondary windings of the transformer 11 and controlled from the synchronizing device 6 1 sludge

Description

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The invention relates to electrical engineering and can be used in thyristor rectifier control systems for inverters with current and voltage regulators.

The aim of the invention is to stabilize the parameters of the output voltage pulses.

The drawing shows a schematic diagram of a device for controlling a three-phase thyristor converter.

The device contains a three-phase transformer 1, phase-shifting capacitors 2, a three-phase uncontrolled rectifier 3, an adjusting resistor 4, a saw-tooth voltage generator 5, a three-phase synchronizing device 6, a distributor 7 pulses. The sawtooth generator consists of the time of the driving capacitor 8, the charging diode 9, the thyristor potential switch 10 of the pulse transformer 11, the extinguishing NS circuit 12 The synchronizing device consists of the control thyristor 13 of the separation diodes 14 of the connecting thyristors 15 of the pulse transformers 16 The pulse distributor consists of thyristors 17 included in the secondary windings of a pulse transformer of a sawtooth voltage generator

The device works as follows.

The three-phase voltage of the transformer 1 after transformation through the phase-dependent capacitors 2 is supplied to the three-phase rectifier 3 The rectified voltage through the resistor 4 charges and winds the driving capacitor 8 of the sawtooth generator 5 In this case, the diode 9 shunts the primary winding of the pulse transformer 11 eliminating in her

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the effect on the charging process of the arshm of the capacitor capacitor; When the voltage of the driving capacitor reaches the triggering value of the thyristor switch 10, this capacitor is discharged through the primary winding of the pulse transformer I. of the triac switch 10 and the extinguished BC chain 12, for example The secondary overrun of the transformer 11 is supplied to the control thyristor 13 for transmitting the signal to the synchronization device b and to the thyristors 17 of the pulse distributor. With constant capacitance, the time setting the capacitor 8 of the resistance The resistor 4 is always chosen such that the process of charging the capacitor 8 to the threshold voltage ends in time within the half-cycle of the alternating voltage of the supply transformer. Then, after the discharge of the capacitor 8 and supplying the control voltage to the thyristor 13 through one of the separation diodes 14, a control current arises in one of the thyristors 15, which will have a greater potential difference at the time of control. This thyristor opens and shunts the power supply circuit of the sawtooth generator. It zeroes out. At the same time, the thyristor clutch 15 remains in a conducting state until natural switching occurs, when the next phase valve should go into operation. At this point, the thyristor 15 closes and the charging capacitor 8 time starts again. The thyristors 15 open and close alternately in accordance with the alternating phase alternating voltage order, synchronizing the operation of the sawtooth generator, impulses are induced in the pulse transformers An emf is applied to the control electrodes of the thyristors 17 of the pulse distributor. The voltage of the secondary windings of the transformer 11 through the thyristors 17 is alternately supplied to the channels a, b, from a relatively common point from these windings. At a constant capacitance of the capacitor 8 and a constant voltage triggered by the switch-on key 10, metered current pulses of the discharge of the capacitor 8 will pass through the primary winding of the transformer 11. This ensures the stabilization of the parameters of the output voltage pulses of the transformer 11 and in channels ab. device. A characteristic feature of the device is the combination of functions by a capacitor 8, which is used not only as a time master, but also as a power element.

accumulating energy for generating control pulses of each of the three channels, the voltage at the time of the driving capacitor at the time of its discharge does not depend on the magnitude of the supply voltage, is determined only by the parameters of the thyristor potential key,

Claims (1)

The device will allow, at minimum cost, due to the use of an insignificant number of simple and reliable elements in the operation of building thyristors. converters with very technical and economic indicators and low cost. A special feature of the device is its ability to use it at increased vibrations and limited areas (for example, when placed on rotating parts of electric machines). At the same time, the stabilization of the parameters of the output pulses during the oscillation of the supply voltage increases the reliability of the converter. A device for controlling a three-phase thyristor converter containing a three-phase transformer, the primary windings of which are intended to be connected to the supply mains, the secondary windings through phase-shifting capacitors are connected to the input of a three-phase uncontrolled rectifier, the cathode output of which is connected to the common point of one output of the regulating element and the output of the resistor, another output of the regulating element is connected to the anode of the first diode, the cathode of which and the other output of the resistor are connected to a common anode of a three-phase zero rectifier made on thyristors, the power supply of each of which includes the primary winding of the corresponding pulse transformer, the output of a three-phase zero rectifier connected to the input of a three-phase uncontrolled rectifier, time setting the capacitor, one output which is connected to the anode output of a three-phase uncontrolled rectifier and one input terminal of the threshold element, the other is connected to the anode of the first diode and another input terminal of the threshold element This key element, the output of which is connected to the control inputs of the thyristors of the three-phase zero rectifier through the corresponding diodes, and the control input is connected to the discharge circuit of the driving capacitor, characterized in that, in order to stabilize the parameters of the output pulses, an additional pulse has been introduced transformer, three thyristors and a second a diode, the other output being connected to the anode of the first diode via the second diode, and to the other input terminal of the threshold element through the primary winding of an additional pulse transformer, the first secondary winding of which is connected to the control input of the key element whose input is connected with the cathode of the first diode, some. outputs of the second, third and fourth secondary windings of the additional pulse transformer F. combined and intended to be connected to the cathodes of the thyristors of the converter, the other terminals of these windings are connected to the anodes of the respective inserted thyristors, the control transitions of which are connected to the terminals of the secondary windings of the pulse transformers, the three-phase zero rectifier ,