SU1094121A2 - Three-phase ac voltage regulator - Google Patents

Abstract

THREE-PHASE ACCESS VOLTAGE REGULATOR according to aut. P. No. 393736, O. a three-phase rectifying bridge, while the cathode of the second charge thyristor is connected to the negative terminal of the three-phase rectifying bridge.

Description

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- "The invention relates to electrical engineering and is intended to regulate the exchanging three-phase voltage at different consumers of electrical energy.

According to the main author. St. No. 393736, a three-phase alternating voltage regulator is known, containing three diode-thyristor switches, three distribution diodes, the cathodes of which are connected to the cathodes of thyristors and 10 thyristor switches, and combined. anodes - with a switching thyristor cathode, a switching capacitor and a choke, a charge thyristor, a trephase rectifying bridge closed by a shunt thyristor, with; By this, the anode of the switching thyristor is connected to the cathode of the charge thyristor and through the switching capacitor and choke to the negative lead of the three- to 20-phase rectifying bridge, to the positive terminal of which the charge thyristor anode fi is connected.

The disadvantage of such a regulator is the presence of a short-loop circuit when the shunt thyristor is turned on, which short-circuits the rectifier bridge at the moment of switching the thyristor switches.

To limit this current, an inductive filter must be included in each phase. But the introduction of the filter only: .... limits this current, which remains always greater than the operating current. Therefore, the elements of the switching circuit are chosen based on the necessity of switching both the operating current and the limited short circuit current.

The aim of the invention is to improve its weight and size parameters.

The goal is achieved by introducing a second 45 charge thyristor into the three-phase AC voltage regulator, connected between the common point of the circuit from the switching droplet, the capacitor and the shunt thyristor cathode, and a 1-phase tap of the three-phase rectifying VQ bridge, when the second charge cathode the thyristor is connected with a minus tap of a three-phase rectifier stop.

The introduction of a second charge thyristor eliminates the formation of a short-circuit and, therefore, the need to include an inductive filter in each file of the power supply network, and a short-circuit current limiting, which improves the device’s weight and dimensions, since the switching thyristors are selected less current and also less switching capacity 65

condenser, which also improves weight and size.

The drawing shows a functional diagram of a variable three-phase voltage regulator.

The proposed device contains a three-phase supply network 1 connected to the load 2 via diode thyristor switches 3-8, charge thyristors 9 and 10, switching capacitor 11, rectifying diode bridge 12-17, switching choke 1 shunting 19 and switching 20 thyristors, distribution diodes 21-23, each of the cathodes of which is connected to one phase of network 1, a: their anodes are combined and connected to the cathode of switching thyristor 20, the anode of which is connected to the cathode of charging thyristor, and through switching commutator 11 and choke 18 connecting with the anode of the charge thyristor 10 and the cathode of the shunt thyristor 19, the anode of which is connected to the anode of the charge thyristor 9 and with the positive terminal of the rectifying bridge 12-17, the negative terminal of which is connected to the cathode of the charge thyristor 10. WCHR of the rectifier 12 -17 bridges are connected respectively to the outputs of the diode-thyristor switches 3-8 and the inputs of the load 2.

The regulator works as follows.

When the mains 1 is turned on before the control pulses are supplied, the current in the load 2 is absent, since the thyristor diodes 3-8 are turned off. When applying control pulses to thyristors 4, b and 8 of diode-thyristor switches 3-8 and charging thyristors 9 and 10, the latter are turned on and the load 2 is applied to the voltage of network 1. Simultaneously the switching capacitor 11 is charged along the circuit: positive terminal rectifying bridge 12-17, first charge thyristor 9, capacitor 11, choke 18, second charge thyristor 10, bridge negative lead 12-17. The polarity of the charge of the capacitor is indicated on the drawing without brackets.

At the moment of time necessary for switching thyristors 4,6 and 8 s, control pulses are removed, control pulses are also removed from charge thyristors 9 and 10, and shunt 19 and commuting 20 thyristors are simultaneously turned on. At the time of their inclusion, the switching capacitor 11 is recharged along the circuit: switching thyristor 20, distribution diodes 21-23, diodes 3, 5 and 7 of diode-thyristor switches 3-8, diodes 12-14 of the rectifying bridge 12-17, shunt thyristor 19, the commutating choke 18. The current recharging 1094121L

Yes, the capacitor 11 is directed to the encounter 19 and the opposite is applied to the load current, due to which the current is from the capacitor 20. Minus

thyristors 4.6 and 8 are interrupted and they are through thyristor 9 to thyristor anode

off. With a time delay of / 19, plus through the choke 18, to the time specified for turning off the thyristor 19 by the ti-tune, and it is turned off. Resistors 4, 6, and 8 after switching on 5 By varying the switching time and switching off switches 19 and 20, the second thyristor 4, 6, and 8 are switched on and the reactive thyristor switches can be switched on by rectifying the voltage from the load.

strutting bridge 12-17, shunting Ti-zero to nominal. ristor 19, charge thyristor 10. According to

polarity recharge, condenser 11 The proposed device is improved in the drawing in parentheses. weight and dimensions indicators, so

The next time you turn on the charge, the formation of a circuit is eliminated.

thyristors 9 and 10 and thyristors 4,6, short-circuit the network at the moment

8 (before this, the control switching 15, and, therefore, the out-of-band signals from the commuting switch are removed, and it shunts the need to install inductive thyristors) to the shunt thyristor filters.

Claims (1)

THREE-PHASE AC VOLTAGE REGULATOR according to Autost No. 393736, characterized in that, in order to improve the overall dimensions, a second charging thyristor is introduced, connected between the common point of the circuit from a switching reactor, capacitor and cathode of a shunt 'thyristor and a negative branch of a three-phase rectifier bridge while the cathode of the second charging thyristor is connected to the negative tap of three KO 4*.