SU620020A1 - Three-phase current switch - Google Patents

Description

(54) THREE PHASE CURRENT SWITCH

The invention relates to the field of automation and electrical engineering and can be used in switching equipment operating in AC circuits.

Three-phase AC switches made on three thyristors and controlled from a source of control signal 1J are known. The disadvantage of these switches is 1 second.

Closest to the proposed are three-phase current switches containing a rectifier, in each phase a thyristor, a load and an electrically protected unit f2j. The disadvantage of these switches is low efficiency, which is caused by losses in their individual units.

The purpose of the invention is to simplify the switch and increase its efficiency.

The goal is achieved by the fact that the three-phase switching device, which contains the load in each phase, the power thyristor and the electronic protection unit, is switched on.

A voltage regulator, a control device made on the transformer, the secondary winding of which is connected to the base of the transistor and to each phase emitter follower and diode, are inserted between the control electrode and the thyristor cathode, and the rectifier whose terminals are connected to the thyristor anodes. The anode of the diode is connected to the anode of the thyristor, and the cathode is connected to the business unit of the electronic protection unit. Moreover, the collectors of all the emitter followers are connected to the collector of the transistor of the control device and voltage regulator, the other output of which is connected to the high voltage collector, the emitters of the repeaters are connected to the collectors of the transistors of the corresponding electronic protection blocks and the base to the emitter of the control transistor.

Claims (3)

In the drawing, a circuit diagram of a switch, each phase of which contains a load 1, a thyristor 2, an electronic protection unit 3, a transistor 4 and a diode 5, is presented. In addition, the switch has a driver 6, a voltage generator 7, and a control device 8 on the transistor 9 and the transformer 10 the three-phase AC switch operates as follows: The control pulses are fed to the aHard of the transformer 1O of the control device 8, from the emitter of the transistor S are sent to the bases of the transistors 4 m odes them TCI {1toe state. the passage of the emergency t (the junction of the pv t and the pa 2 through the zero value of the eject block) of the protection 3 is in the closed state and the control impulse is amplified in power, from the transistor 4 PEChpunt into the chain and the power thyristor 2. When a tick passes through a control electrode circuit, the power thyristor is turned on, since the electronic protection unit is closed only at the mass passes of the anode current of the thyristor through zero, and during the ettalny time, the power thyristor turns on only at this moment . In the case of the absence of control pulses, the thyristor is upgraded at the moment of anode 0k change to a greater, smaller holding current. An increase in load current 1 over the setpoint value causes the electronic protection unit 3 to trip, which bypasses the power thyristor 2, and at the moment changed :( The polarity of the voltage at the anode of the power thyristor is turned off. When the control pulses arrive at the base of the transistor 4, when the direction of the anode of the power thyristor is positive with respect to the cathode e load exceeding the set value ,, thyristor switch not proiskhodit.taK; his control circuit shunted otkryoym unit elek1 ronnoy zaischty 3. Due to the fact that in any mode of operation, the switching switch is carried out when the voltage goes over zero, the switch can be used in any kind of load peaks (inductive, switch-capacitive, inductive-active), with changes in load parameters over a wide range the minimum level of the interference spectrum in the power supply network without imposing strict requirements on the anodic current rise rate in MObieHT of switching on the power thyristor. Claims of the Invention A three-phase current switch comprising in each phase a load, a power thyristor and a blackjack electronic switch connected between the control alev; the thrasad and the thyristor cathode, and the rectifier, the terminals of which are connected to the anodes of the thyristors, characterized in that, in order to simplify the switch and improve its efficiency, a voltage regulator, a control device, made on a single line, is inserted into it. formatter, the secondary winding is connected to the base of the transistor, each emitter emitter follower and diode whose circuit is connected to the anode tirzh, torus, and the cathode to the divider of the electronic protection unit, and the collectors of all emitter repeaters are connected to the collector of the transistor control april device and stabilizer congestion, another KOfraporo pin is connected to the rectifier | mitter repeaters are connected to the collectors of the transistors of the corresponding protection modules, and bugs are connected to the transistor of the control transistor, which is controlled (information sources taken during examination: 1. S. Brufman, N. Trofimov | P. | Variable switches of a variable, M., Energie, 1969, pp. 22-29, 2, USSR Author's Certificate of 413623 cells, NOZK 17/56, 7.04,71. Il.