SU1387139A1 - Thyristor control unit - Google Patents

Abstract

The invention relates to electrical engineering and can be used for phase control of thyristors operating under inductive load. The aim of the invention is to simplify. The goal is achieved by the fact that the switching circuit of the power thyristor 1 is made up of a switch 3 connected to the series-connected capacitor 2 and the primary winding of the pulse transformer 4, the secondary winding of which is connected to the control terminal of the power thyristor 1. The capacitor 2 is connected to a switching source the power supply, and the input of the key 3 is connected to the output of the phase-shifting unit 5. Thus, the number of power sources is reduced, which simplifies the device. 1 il.

Description

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The invention relates to electrical engineering and can be used for phase control of power thyristors.

The aim of the invention is to simplify.

The drawing shows a schematic diagram of the device.

The device for controlling the thyristor 1 contains a storage capacitor 2 connected via a thyristor switch 3 to the primary winding of the pulse transformer 4, the secondary winding of which is connected to the control transition of the thyristor I. The control input of switch 3 is connected to the output of the phase-shifting unit 5. Connection point of one output the capacitor 2 with the anode of the key 3 and the cathode of the Zener diode 6 is connected to the same terminal of the AC power supply 7, the other terminal of which is connected through the capacitor 8 to the junction point of two atelno included diodes 9 and 10 are connected in parallel and in accordance with the zener 6, the anode of which is connected to the junction between the other output of the capacitor 2 from the end of the primary winding of the transformer 4. The load 11 is connected in series with the thyristor 1 to 7 source circuit.

The device works as follows.

When a positive voltage appears on the cathode of the thyristor 1, the capacitor 8 through the diode 9 in the first half of the half-period is charged to the amplitude value of the voltage UHHT. In the second half of the positive half cycle, the capacitor 8 is discharged through the power supply 7, the capacitor 2 and the diode 10, charging the capacitor 2 to the voltage of the breakdown of the zener diode 6.

During the negative half-wave action of the supply voltage, the phase-shifting unit 6 turns on the thyristor switch 3, as a result of which an abrupt voltage of the capacitor 2 is applied to the primary winding of the transformer 4. When

This forms a trigger pulse, which is fed to the control transition of the power thyristor 1, opening it. The triggering pulse lasts until the capacitor 8 is fully discharged. In subsequent cycles of a power alternating voltage, the described operation cycle of the thyristor converter is repeated. With the phase shifting unit 5, the switching on angle of the power thyristor 1 varies from zero to 180 degrees.

Thus, by combining the elements, the proposed device for controlling the thyristor is simplified by reducing the number of power sources.

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Claims (1)

Invention Formula A device for controlling the thyristor, containing a storage capacitor connected via a thyristor switch, the control input of which is connected to the output phase-shifting unit, to the primary winding of a pulse transformer, the secondary winding of which is intended to be connected to the thyristor control transition, an AC power supply, one terminal of which is connected to one the output of the storage capacitor, and the other through the capacitor - to the junction point of two series-connected diodes, and a zener diode, characterized in that, for the purpose of simplification, the series-connected diodes are connected in parallel and according to the zener diode, the cathode of which is connected to one and the anode to the other terminals of the storage capacitor.