SU758462A1 - Device for control of thyristors with antiparallel switching on of high-voltage change-over switch - Google Patents

Description

The invention relates to high voltage (thyristor switches solder power transformers, specifically to a device for distributing control pulses.

A device for controlling thyristors containing a thyristor unlocking unit transmitting a high voltage cable with a control pulse distribution system made in the form of high voltage pulse transformers (1] and [2] is known.

This device is complicated and expensive.

The closest technical solution for the achieved result to the invention is a device for controlling thyristors with antiparallel switching on of a high voltage switch, containing a thyristor unlocking unit, transmitting a cable with a control pulse distribution system [3].

The disadvantage of this device is its complexity.

The aim of the invention is to simplify the thyristor control device.

This goal is achieved by the fact that the device for. control thyristors with anti2 (parallel switching on of the high-voltage switch, containing the thyristor unlocking unit, transmitting cable with a control pulse distribution system, characterized in that the control pulse distribution system is made on sealed magnetically controlled contacts with ferromagnetic springs (reed switches) connecting the control electrodes to each other thyristors connected antiparallel through a limiting resistor, and the reed field excitation windings connected to a low-voltage cable it to the unit thyristor firing.

In FIG. 1 shows the placement of the main elements of a high-voltage thyristor switch and their interconnection, 'in FIG. 2 shows a control pulse distribution unit; in FIG. 3 shows a cell of counter-parallel connected thyristors controlled by a reed switch.

A device for controlling thyristors with antiparallel switching on of a high-voltage switch for soldering a power transformer contains an automation cabinet 1 connected by a cable with unlocking blocks 2 made on reed switches 3 connecting the control electrodes of each cell of on-parallel connected thyristors.

The cells 4 of the thyristors are connected to the tap of the high-voltage winding 5, located in the tank 6 with oil.

Each reed switch is placed between the poles of the U-shaped magnetic circuit 7, on which the reed excitation winding 8 is placed. The ends of the winding 8 are removed from the tank 6 and are connected by a cable to the automation cabinet 1.

The gaps between the terminals of the reed switch, the magnetic circuit 9 and the field winding 8 are designed for the full operating voltage of the high-voltage thyristor switch. To reduce these gaps and prevent their breakdown, the reed switch, the magnetic circuit and the field winding are sealed with a dielectric with high electrical strength. When the reed switch is activated and the control electrodes of the thyristors of one cell are connected to each other, this cell is unlocked and attaches the corresponding terminal of the high-voltage winding;

The thyristors are unlocked by bias current pulses, the anode voltage formed from them, which branches into the control transitions of the thyristors through the contacts of the reed switch and the limiting resistor R at the beginning of each half-period of the mains voltage. The thyristor T1 is switched on by the current flowing through the cathode, the control electrode T2, the resistor R, the contacts of the reed switch 3 and the current electrode - the cathode T1.

When the thyristor T1 is turned on, the lazy signal is automatically removed from it, the voltage drop across the open thyristor does not exceed 1 V. When the current sinusoid passes through zero, the thyristor T1 closes.

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With the start of the next half-wave, T2 is unlocked in a similar way.

Thus, the control pulses arrive at the thyristors synchronously with the mains voltage at the beginning of each positive half-period of the network with constantly closed contacts of the reed switch. The time of the closed state of the contacts of the reed switch is determined by the necessary time to turn on the switch on this tap of the transformer.

The use of this device simplifies the control pulse distribution system.

Claims (3)

The cable with blocks 2 is unlocked, performed by HetfflbiMH on reed switches 3, which interconnect the control electrodes of each cell 4 counter-parallel to the on-line thyristors. Cells 4 thyristors are connected to the high voltage winding tap 5, located in the tank 6 with oil. Each reed switch is placed between the poles of the U-shaped magnetic core 7, on which is placed the winding 8 of the reed switch excitation. The end of the winding 8 is taken out of the tank 6 and connected by cable to the terminal 1 of the automation. The gaps between the terminals of the reed switch, mag- netline 9 and the excitation winding 8 are designed for the full operating voltage of the high-voltage thyristor switch. To reduce these gaps and prevent their breakdown, the reed switch, the magnetic conductor and the excitation winding are sealed with a dielectric with high electrical strength. When the reed switch is triggered and interconnected between the control electrodes of the thyristors of one cell, this cell is unlocked and connects the corresponding output of the high-voltage winding. the limiting resistor R at the beginning of each half-period of the network voltage. The thyristor T1 is turned on by the current flowing through the cathode - the pickup electrode T2, the resistor R, the contacts of the reed switch 3 and the control electrode - the cathode T1. When the thyristor T1 is unlocked, the control signal is automatically removed from it, so as the voltage drop across the open thyristor does not exceed 1 V. When the current sinusoid passes through zero, the TI thyristor closes. Starting from the next half-wave in the same way, T2 is unlocked. Thus, the control pulses arrive at the thyristors synchronously with the voltage of the network at the beginning of each positive half-period of the network with permanently closed reed switch contacts. The time of the closed contact of the reed switch is determined by the required turn-on time of the switch on this tap of the transformer. The use of this device simplifies the control pulse distribution system. Claims An apparatus for controlling thyristors with an anti-parallel connection of a high-voltage switch comprising a thyristor de-energizing unit, a transmission cable with a control pulse distribution system, which is designed to simplify the distribution of control pulses on sealed magnetically controlled contacts with ferromagnetic springs (reed), connecting control electrodes with antiparallel thyristors through a limiting resistor, and The bobbins are excited by dry-pockets connected by a low-voltage cable to the tarottor device. Sources of information ,, 1fin t1 1e into account when examining 1. USSR author's certificate No. 259998, CL. H 02 R 13/16, 1968. 2. Authors certificate of the USSR N 256049, CL. H 02 R 13/16, 1968. 3. The UK patent number 1252139, CL. Н2 (ШН). 1971. V 7 / t And