SU826302A1 - Converter with step regulation of output voltage - Google Patents

Description

I

The invention relates to electrical engineering and is intended for use at direct current electric substations.

Converters with output voltage regulation are known by connecting to a main rectifier connected in series on the DC side of booster rectifiers (VDV) shunted by diodes l j | and L2J.

The closest to the present invention is a converter with step regulation of the output voltage, containing a main uncontrolled rectifier and several series-connected and diode-biased diodes on the DC side of the booster rectifiers, made on the thyristors and uncontrolled ventilators in a three-phase bridge circuit, thyristors are connected to controlled groups.

associated with a 2G control pulse driver

The connection of the airborne troops is carried out by supplying control pulses to the airborne thyristors at the moments of their natural switching. In this case, a step change in the voltage at the output of the converter causes load current jumps at high speeds; This can worsen the operation of electric locomotive engines due to arcing and circular current on the collector. In addition, due to the presence of a smoothing device, an abrupt change in the controlled voltage leads to significant fluctuations in the rectified voltage, which can cause interference to the communication lines.

The purpose of the invention is to increase reliability.

Claims (2)

This goal is achieved by the fact that, in the converter, controlled groups of bridge circuits of booster rectifiers are placed alternately in their anode and cathode circuits, and the driver is connected to the circuits of controlling the thyristors of all these groups through a logic unit providing the shift of the first control pulse supplied thyristors of equal groups of each included booster rectifier with a lead of 60 el. hail, from the moment of natural switching thyristors of this group. FIG. 1 shows a converter; in fig. 2 is a logic block diagram. The converter (Fig. 1) contains serially connected main converter 1 and three semi-equal airborne units 2-4 with thyristors installed alternately in their anodic and cathodic groups. Airborne voltage strains are selected in increasing sequence with the difference between adjacent ones no more than the value determined by the conditions of the required quality of regulation and the minimum of the connected airborne forces. The control of the airborne thyristors is carried out from a control circuit including logic and shapers of 7 and 8 pulses. Block of logic 1FIG. 2} consists of two flip-flops 9 and 10 with dynamic inputs, logic circuits 11 and 12, and an output unit 13. The control voltage is carried out as follows. With the selected airborne voltage of 2-4 UjlOO V, and 200 V and U4 400 V in the sequence defined by the binary code, there are the following levels of adjustable output voltage of the converter with a magnitude of 100 V: 1) 000, 2) 100, 3) 010, 4) 110, 5) 001, 6) 101, 7) 011 and 8) 111, where O is the disabled state and G is the enabled state of the corresponding airborne forces. The decrease in voltage occurs in reverse order. To obtain the next voltage level, they include either only one airborne force (transitions from 1 to 2, from 4 to 5 and from 6 to 7 levels of regulation) or simultaneously disconnect another airborne forces (transitions from 2 to 3, from 3 to 4 and from 5 to 6 and reverse them when (decreasing the output voltage). In this case, at any of the 24 transitions of the on and off VDV, the controlled valves are in different groups (anodic and cathodic or vice versa). Consider the process of turning off one of the airborne forces 2 and the inclusion of another VDV 3. On the circuit AND logical unit 6 of the control circuit 5 from one From the formers 7, the pulses are constantly received in phase with the natural switching point of the controlled group of valves of the operating airborne unit, and the AND 12 circuit from the second generator 8 receives pulses shifted by 60 el.grad towards the leading side. the law of regulation of the Airborne Forces 2 must be turned off, the circuit 12 from the output I of the trigger 10 receives a signal O, and from the output 11 of the trigger 9 - 1. The circuit 11 from the output I of the trigger 9 receives a signal O. With this, both schemes -. There are no pulses at the output unit 13 and the latter does not issue control pulses to the thyristors of the disconnected airborne forces 2. When a command is received to activate the airborne forces from the voltage regulator, the trigger 10 switches, and a signal 12 appears at its output J permits the supply of pulses to the output unit 13, and the latter issues a control pulse to the airborne thyristors. Simultaneously, the pulse arrives at the input of the trigger 9 and switches it. At the same time, a signal 1 appears at the output J of the flip-flop, at the output of the C - O. The circuit 11 starts to transmit pulses to the output unit 13, the circuit 12 is closed. When a command is received to turn off the Airborne Forces, trigger 9 switches and the circuit returns to its original position. I.Z of the above it is clear that the logic block provides the supply of the first impulse of control to the switch on airborne forces with an advance of 60 el.grad. relative to the moment of natural commutation of its controlled group. The diagram (Fig. 3) shows these control pulses (i,) and the order in which they are delivered. Curves V and V represent the output voltages of the respective airborne forces 2 and 3. The diagram below shows the sinusoids of the phase voltages of the windings of these airborne forces. Formula of the invention Converter with stepwise regulation of the output voltage, containing the main uncontrolled rectifier and several serially connected and shunt diodes on the DC side of the booster rectifiers performed on the thyristors and out of control The fans are three-phase bridge circuits, and the thyristors are connected to controlled groups connected to a control pulse shaper, characterized in that, in order to increase reliability, adjustable bridge groups of booster rectifier circuits are placed alternately in their anode and cathode circuits, and the aforesaid driver is connected to the thyristor control circuits of all specified control groups via a logic block, which provides a shift of the first control pulse supplied to the control thyristors of each included booster rectifier with advance by 60 zl.grad. from the moment of natural commutation of this group. Sources of information taken into account during the examination 1. USSR author's certificate No. 214650, cl. N. 02 R 13/24, 1961. 2. The patent of France No. 2184916, cl. H 02 R 13/16, 1965. um rester aa wives Lee