SU1332476A1 - Device for forming the driving pulses for the pulse-phase control system of a thyristor converter - Google Patents

Abstract

The invention relates to electrical engineering and can be used in systems of pulse-phase control of converters. The aim of the invention is to twist the symmetry of the synchronization pulses and control them. The device generates the first and second master pulses shifted relative to each other by 2; i7in in the interval of 5 fl / 3, and duplicating the master pulses. Using the 1K-trigger, their moments of occurrence are compared and the level of asymmetry is determined by a signal at its output. In the presence of asymmetry, change the parameters of time-shapers. 3 il. (L

Description

The invention relates to electrical engineering and can be used in systems of pulse-phase control of thyristor-based and transducers.

The purpose of the invention is to increase the symmetry of the driving pulses of the thyristor converter control system.

FIG. 1 shows a block diagram of an apparatus for carrying out the proposed method; in fig. 2 and 3 are potential time diagrams that illustrate the operation of the device.

ten

The input of the device receives the voltage of one of the phases of the mains Un; i (Figs. 1 and 2), which is filtered by the RC filter and shifted by it by the angle Y. This voltage goes to the input of the zero-organ 2. At the moment of passing the negative half-wave voltage Uux (Fig. 2a) rectangular pulses of duration (Fig. 26) are removed from the zero-organ output and at the time of the rising edges of these pulses using an RC circuit, synchronizing pulses are formed. The device contains a filter 1, 15 first logical zeros U ,, / (fig. 2c),

Connected to a single-phase supply voltage Uj. The output of filter 1 is connected to the input of a null organ 2, the output of which is connected via the differentiating EC-circuit-3 to the input of the third one-oscillator 4. The output of the latter through the differentiating RC-circuit 5 is connected with the input of the fourth one-oscillator 6, its direct output through the differentiating KS circuit 7 is connected to the input of the first single vibrator 8, and the inverse output to the first input of the first AND 9 element 9.

The output of the fifth one-shot is connected to the second input of the element AND-HE 9, the output of which is connected to the input of the first element NOT 10 and the first input of the second element AND-NOT 11. The output of the last is connected to the first input of the fourth element AND-NOT 12, the output of which is connected with output terminal

UflbK device and through the second element is NOT 13 with the input of the first one-shot 14.

The output of the one-shot 14 through the differentiating RC-circuit 15 is connected to the input of the second one-shot 16, the output of which through the differentiating RC-circuit 17 and the third element NOT 18 is connected to the second input of the third element AND-HE 19, the second input of the second element NAND, while the first input of the NAND 19 element is connected to the output of the first inverter, and the output to the first input of the trigger 20, the second input of which is connected to the second input of the fourth NAND element, which through a differentiating RC circuit connected to the output of the zero-organ, the output of the trigger 20 through the amplifier 21 St It is engaged with the node 22 of the indication of the symmetry of the driving pulses.

The device works as follows.

The input of the device receives the voltage of one of the phases of the mains Un; i (Figs. 1 and 2), which is filtered by the RC filter and shifted by it by the angle Y. This voltage goes to the input of the zero-organ 2. At the moment of passing the negative half-wave Uux voltages (Fig. 2a), square-wave pulses of duration (Fig. 26) are removed from the zero-organ output, and at the time of the rising edges of these pulses, using a RC circuit, synchronizing pulses are generated that trigger the third one-oscillator 4 and are applied to the resetting 1K-trigger input and the second input Werth NAND 12.

The third one-shot 4 are formed by rectangular pulses of duration 2 G

at the moment of passage

no more -

m

The days of the leading edges of which, using a differentiating RC circuit 5, form the second logical zeros Uoi (time tj, fig.2d), used to start the single-oscillator 6, the output pulses of which Ufe (fig. 2e) of 57G duration (back fronts) are used to form /

the third logical zeros Uoj (Fig. 2g). .

The third logical zeros trigger the one-shot 8. The duration of its output pulse is also equal to

(fng. 2 s).

The total duration of exposures of single vibrators 6 and 8 is chosen from the ratio

(| - -tjcL) + / 3 + tnMn 5 (+ tiQ,) (2 (r / m-t3q) +,

where the total duration of the outgoing pulses of one-shot 14 16 (equal to, where m is the pulse of the power circuit of the TP);

tjoAe and t

- the duration of the output pulses of the single vibrators 6 and zaf, the duration of the pulses of the single vibrator 4, is equal to.

The signals Ue and g (Fig. 3 and 3h) from the inverse outflows of the one-shot 6 and 8 are summed by element 9, from the output of which at the moment of time the pulse Uj is removed with a duration

3

 (+ which is fed simultaneously to the input of the element NOT 10 and to the first input of the element NAND.

The formation of the driving pulses with a frequency tG occurs as follows.

The signals of logic zeros U ,, o / are used not only to form the first driving pulses in a series, but also to form all subsequent pulses Ugbu (Fig. 2L) through the interval. in the range of 5 (/ 3T (Fig. 2k). The interval is formed by two consecutively via a differentiating KS circuit with a single vibrator 14 and 16. The total time delay of one-shot 14 and 16 is set to 2 / G / T.

A series of pulses U, j from the output is eleterval 2 / G / t at time t (fi Zi). This pulse does not trigger one vibrators 14 and 16, since at the time moment g the pulse is not removed from the NAND 11 element (Fig. 2k). The selection of this pulse (duplicate J imprint is at the output of the circuit of the AND-NE element 19 due to the formation of the resolution signal 10 (Fig. 3) at the output of the inverter 10, while the pulses U | f

(Fig. 3) through the element AND-NOT 19 is not passed, because at time tj. . . no permission.

15 When comparing time signals, duplicate signals (logical and, o, fig. 3) and signals C, o- (fig. 2c) in the case of symmetry Ug, (fig. 2, the leading edges of these pulses

20 is given, which is fixed by the induction unit 22 containing the trigger, amplify and the LED.

With symmetry Ug on the outputs of the trigger 20 and the amplifier 21 is set

and Ujj, equal to the power supply voltage + Un and therefore, the output current does not pass through the LED and it does not light up (Fig. 3k, l).

The HE 13 (Fig. 3a) periodically triggers a one-shot 14. Its output pulses, UK, are generated by a duration of / a / t (Fig. 3B) and are converted. 25 signals are sent to logic zero signals using an RC differentiating chain 15 (Fig. 3 Sv).

Pulses and, 04 start. A single-pulse, the output pulse of which is also 30 pulse fronts and

When symmetry is broken, n

form duration / g / ha (fig.Zg). These pulses are differentiated by circuit 17 (Fig. A). The resulting logical zeros are used to obtain subsequent pulses in the series (at times tj ... .ty), for which they are inverted by the element HE, 18.

Thus, at the output of the inverter 18, a series of impulses is formed.

(with a shift between pulses by 2 7 7 hectares) .40 nor an inductor. These pulses arrive at the second input of the element AND-NO 11, from the output of which until then pulses are output to the element AND-NO 12, as long as there is an enabling signal at the first input of element 11 with a duration of 3 / G / C. The ion is matched (Fig. 4m), while the outputs of flip-flop 20 and amplifier 2 show dips of constant voltage (Fig. 3 N. O), the duration of which 35 is determined by the level of unmet meter (Fig. 3 l).

Restoration of a given symmetry is achieved by changing the vapor of the one-shot 16 to a full ha.

45

this at the output of the device go | (fig. 2l) in the period of time t -t we have a sequence of pulses with a frequency mf.

The device scheme allows for continuous monitoring of the symmetry of the intervals between pulses in a series and makes it possible to restore the specified level of symmetry, for which the pulse formed at time t (Fig. Ze) is used to form a special backup pulse U (3, ..., o through i) .

Claims (1)

Invention Formula A device for forming a back louijix pulse of a pulse-phase control system of a thyristor converter containing a null organ with a shortening KS circuit at the output of two consecutively connected vibrators through a differentiating R 5Q circuit with a shortening RC circuit on during the second one-shot, the third one-shot, the input of which through the RC-circuit is connected to the zero-org output, characterized in that 55 aiming to increase the symmetry of the driving pulses, it is equipped with the fourth fifth one-shot, four AND-NOT elements, three NOT elements, an amplifier trigger at the output 32476 interval 2 / G / t at time t (Fig. Z). This pulse does not trigger single-vibrators 14 and 16, since at time moment g, the pulses from the N-11 element are not removed (Fig. 2k). The selection of this pulse (duplicated J is carried out at the output of the circuit of the IS-NE element 19 due to the formation of the resolution signal 10 (Fig. 3) at the output of the inverter 10, while the pulses U | f (Fig. 3) through the element AND-NOT 19 is not passed, because at time tj. . . no permission. 15 When comparing the time positions of duplicate signals (logical zeros and, o, fig. 3) and signals C, o- (fig. 2c) in the case of symmetry Ug, (fig. 2l), the leading edges of these pulses coincide20 give what is fixed by node 22 display containing the trigger, amplifier and LED. With the symmetry Ug at the outputs of the trigger 20 and the amplifier 21, the settings Ujj are equal to the supply voltage + Un and therefore the output does not pass the current through the LED and it does not glow (Fig. 3k, l). .25 signals impulse fronts and When the symmetry is broken, the leading edges of the pulses and do not match (Fig. 4 m), while the outputs of the trigger 20 and the amplifier 2I appear dips of a constant voltage (Fig. 3 N. O), the duration of which is determined by the level of asymmetry (Fig. 3l). Restoration of a given symmetry. is achieved by changing the parameters of the one-shot 16 until the inductor is completely quenched. Invention Formula A device for generating a pulse-xix pulse of a pulse-phase control system of a thyristor converter containing a null organ with a shortening QC circuit at the output, two serially connected single-vibrator through a differentiating RC circuit with a shortening RC circuit at the output of the second single-oscillator, the third single-vibration whose input via an RC circuit is connected to a null organ output, characterized in that, with the purpose of increasing the symmetry of the driving pulses, it is equipped with fourth and fifth one-shot, four AND-NOT elements, three NOT elements, an amplifier trigger at the output and l 1 a pulse symmetry indication node, the fourth one-shot having the direct and inverse outputs, the output of the third one-shot through the differentiating RC-circuit connected to the input of the fourth one-shot, the inverse output of which is connected to the first input of the first AND-NO element, and the direct output through the differentiating EC-circuit is connected to the input of the fifth one-one, the output of the latter is connected to the second input of the first NAND element, the output of which through the first element is NOT connected to the first input of the second AND-NAND element and to the first input of the third ementa NAND directly output the last is connected to the first input 32476 the fourth NAND element, the second input of which is connected through the differentiating EC circuit with the output of the zero organ and the second trigger input directly, the output of the fourth NAND element is connected to the output of the device and through the second element NOT to the first single vibrator, the output the second one-vibrator with a shortening EC circuit at the output through the third element is NOT connected to the second input of the third element AND-NOT and the second input of the second element AND-NOT, and the output of the last 15 is connected to the first input of the trigger, the output of which is through the amplifier a node defining symmetry indicating pulses. FIG. / FIG, g FIG. H