SU1368941A1 - Device for monitoring the state of parallel-connected thyristors of converter - Google Patents

Abstract

The invention relates to electrical engineering and can be used to monitor the health of parallel-connected thyristors of the converter. The aim of the invention is to increase reliability, speed and increased functionality. The power current through the controlled thyristor 3 creates a constant voltage at its control junction to the input of the null indicator 5, and from its output through the optron 13 to the summing element 14. The goal is achieved by eliminating . 1 pe. about s

Description

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In the protection scheme and. alarms.

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The invention relates to electrical engineering and can be used to monitor the health of a parallel connected thyristor transform tel.

The purpose of the invention is to increase the reliability, speed and enhanced functionality of the device.

Fia drawing shows a diagram of the proposed device.

The secondary winding of the pulse transformer 1, which is included in the pulse control system of the converter, is connected via diode 2 to the thyristor 3 control junction and rectifier 1digital 4, inverting the zero-input (of the shifter 5 through the resistor 6 to the control unit). Tiris 1or 3 and through the resistor 7 to the negative bias source, the resistor 8 and the diode 9, and the input inverter through the I O resistor and the diode 11 to the secondary winding of the pulse transformer 1 and through the resistor 12 to the common the point vtr - blinked, and the output of the null indicator 5 is connected to the input of the optocoupler 13, the output of which through the summing body I-I is connected to the protection and signaling circuit,

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The device works as follows.

When a 1-p-1-pulsed transformer 1 of two-pole pulses appears on the secondary winding, it receives power from the null indicator 5 through a single-half-period expander A. At the same time, these pulses through the diode 1 and resistor 10 are fed to a non-inverting input zero. indicator 5 and through diode 2 to the thyristor 3 control transition, as well as through the resistor 6 to the inverting input zero of the indicator 5. With the same pulse shape on the secondary winding of the pulse transformer and the control transition, which corresponds to the closed state of the thyristor, and the output of the zero indicator is present are positive signal as the signal strength on the secondary winding of the transformer is greater than on the steered switching thyristor. In addition, a negative is fed to the inverting input of the null indicator 5 through a resistor 8

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This is a direct shift from diode 9, which ensures the maintenance of a positive potential at the output of the zero indicator in the intervals between the high-frequency pulses.

When current flows through thyrisor 3 at its control transition

a fall impulse is appearing

10 neither. the duration of which corresponds to the duration of the current flow, and the amplitude exceeds the amount of negative mixing on the diode 9. In this mode, a negative signal appears at the zero-indicator1f pa 5 output, affecting the optical isolation switch i3, as a result of which a signal is generated at its output, which post at the input of the summing body 14.

20 In the summing body, an alarm is generated by comparing the sum signal with a setpoint, which is selected from the conditions of the minimum allowable number of honest valves in the parallel circuits of the thyristor converter. inductive current dividers in the power circuits of thyristors eliminates the dependence of the operation of the device on the parameters of the power circuit, increases speed and reliability, as well as expands the scope of use due to the possibility of using converters without inductive current dividers.

Claims (1)

Invention Formula A device for monitoring the state of parallel-connected thyristors of the converter, equipped with control system with channels by the number of thyristors, containing a summing organ, and by the number of controlled thyristors, control blocks, each of which includes the first a diode, a first resistor, a two-input null indicator and an optocoupler, characterized in that, in order to increase reliability, speed and functionality, a rectifier with a two-polar output, a second and a third diode, are introduced into each control unit, the third, quarter and fifth resistors, with the first the rectifier input is designed to connect the converter control system to the first output channel of the converter control system connected to the thyristor cathode controlled by the second control input of the rectifier to the second output control of the specified channel of the converter control system; connected to the anodes of the first and second diodes, the cathode of the first diode through the first resistor is connected to the common output terminal of the miter connected to the anode of the third diode, and through the second Zistor - with the first input of the null indicator, the power terminals of which are connected to the output terminals of the solders, the second input through the third resistor is connected to the cathode of the second diode, intended for connection with the control electrode of the corresponding controlled thyristor, and through the fourth resistor is connected to the cathode the third diode, through the fifth resistor to the negative output of the rectifier, the output of the null indicator is connected to the input of the optocoupler, the output of which is connected to one of the inputs of the summing organ.