SU1432695A1 - Apparatus for pulsed-phase control of thyristor converter - Google Patents

Abstract

The invention relates to electrical engineering and can be used in converter equipment for controlling thyristor converters with natural switching thyristors powered by a high-frequency power source with an unstable voltage. The aim of the invention is to fix (a. The device for pulse-phase control of thyristor converters consists of synchronization blocks 1, phase displacement 2, distribution 3, stable frequency generator 6. Introduction to the control system of an additional integrator 4, comparator 7, frequency divider 8, element 9 matches and switch 5 allows to exclude a voltage controlled oscillator. 2 or s (L

Description

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The invention relates to electrical engineering, in particular, to converter equipment, namely, devices for pulse-phase adjustment of natural-switching thyristor-type gate-type converters, and is intended to control direct-link thyristor frequency converters powered by an increased frequency energy source, with unstable in frequency and

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module voltage and can be used for mobile agricultural units with an autonomous power source.

The aim of the invention is to simplify the device.

FIG. 1 shows a diagram of a device for pulse-phase control of thyristor converters; in fig. 2 - timing charts of the device.

The device of pulse-phase control (Figo 1) contains synchronization blocks 1, phase displacement 2, distribution 3, integrator 4, the input of which is supplied by the control voltage and through the switch 5, the reference voltage 1)., The uncontrolled stable frequency generator 6, comparator 7, frequency divider 8 and coincidence element 9.

Synchronization unit 1 includes a three-phase transformer, the primary winding of which is connected to a star and four three-phase groups of antiphase-connected secondary windings, both printing phase shift 30 zlhrad, transistor switches for matching the synchronization voltage with the voltage level of logic elements and logic generating synchronization pulses. ,

The phase offset unit 2 (Fig. 1) consists of three by the number of phases of the power supply network, the same nodes 10-1, fig 1, consisting respectively of two elements 13 and 4 of coincidence, which serve to separately feed the counting pulses to the input. or Subtracting a multi-bit reversible counter 15 and a driver 16 for driving pulses.

FIG. 2 presents: 17 — strands of the 1st phase of a three-phase network; 18 - pulses with the following frequency 6 fj, corresponding to the moments of transition of linear and phase voltages through n

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left value; 19 is the output voltage of the integrator 4; 20 - the signal at the output of the element And 9; 21, 22 - strobing synchronization pulses, corresponding to the measurement interval of 30 al. and an adjustment interval lasting 150 degrees; 23, 24 - pulses at the output of the elements And 13 and 14; 25 - pulses at the output of the counter 15; 26-28 pulses at the output of the formers 16 of each channel, arriving at the input of the distributor 3 pulses.

In addition, the synchronization unit generates six pulses of a duration equal to the control range of 150 al. Degrees. and employees to isolate the work area of the thyristors, operating in the positive or negative half-periods of the three-phase network.

The device works as follows.

From the three-phase system of input supply voltages 17 (Fig. 2), at the moment the phase and linear voltages go through zero, a sequence of pulses 18 are formed in synchronization unit 1, which controls the operation of the switch 5. Depending on the state of the switch, on or off 5 at the output of the integrator 4, either the maximum or linearly varying voltage 19 is determined, determined by the parameters of the integrating circuit and the control voltage, which is then processed by the comparator 7 and logically multiplied with the pulses a stable frequency generator 6 using an AND 9 element, at the output of which a batch of pulses 20 of constant frequency is formed, but with a duration determined by the control voltage and power supply period. The pulses form 20 common for all phases of the converter, but are distributed across nodes 10- 12 phase-shifting device 2 in strict accordance with the phases of the supply voltage 17, for example, for phase A, the input of the subtraction of the reversible counter 15 pulses 20 are received through the element 13 and 13 only in the presence of a synchronizing pulse 21, produced synchronized by block 1, which corresponds to the timing diagram 23 (figure 2). The next time to enter the addition of the reversible counter 15

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pulses come from frequency divider 8 through element 14 in the presence of a synchronization pulse 22, which also generates synchronization by unit 1, at the time of zero counter 15 (time diagram 25), pulse shaper 16 generates a control pulse 26. Formation of pulses 27 and 28 for phases B and C It is similar to Phase A pulse 26. The control pulses 26-28 are amplified and distributed along the thyristor control transitions in distribution unit 3 in accordance with the clock pulses 29 of synchronization unit 1.

Thus, the proposed device performs phase control of the converter in the range of 150 electrons, hail, with fluctuations in the frequency of the mains supply when using more simple technical means, in particular, an unregulated frequency generator.

Claims (1)

Invention Formula A device for pulse-phase control of a thyristor converter containing an unregulated stable frequency generator, a sync block. the frequency of the sync pulses is sixfold with respect to the network frequency, and for each phase - the outputs of the gate pulses, which determine the range of variation of the control angle of the converter and the formation of pulses inverse to the pulses; 95 control by the number of phases of the network and the distributor of control pulses, each of the phase control blocks, is made in the form of two AND elements, a reversible counter and a t-ttulformer, the output of which is connected to the input of the pulse distributor, the input - with the output of the reversible counter, direct and the inverse inputs of which are connected to the outputs of the elements I, the first inputs of which are connected to the indicated outputs of the formation of gating pulses and pulses inverse to the gate pulses of the synchronization unit, characterized in that, for the purpose of simplification, it is provided with an integrator, a switch, a comparator, a frequency divider and a third AND element, the first input of the integrator is intended to be connected to a control voltage source, the second input is through a switch - the dp connection of the reference voltage source, the control input of the switch is connected to a six-fold frequency reference to the output of the sync pulse the synchronization unit, the integrator output is connected to the input of a comparator connected in series with one of the inputs of the third match element, the other input of which is connected to the output an uncontrolled generator of stable frequency and the input of the frequency divider, the output of the latter and the coincidence output of the third element are connected to second inputs of the first and second elements AND phase mixing units. L 18 M N M 27 28