SU982506A1 - D.c. voltage-to-d.c. voltage converter - Google Patents

Abstract

CONSTANT VOLTAGE CONVERTER CONSTANT CONVERTER, - containing a regulating element connected between the input and output terminals in series with the input filter, made in the form of a bridge on four thyristors, the diagonal of which includes a switching capacitor and a control unit, different in that in order to extend the range of regulation output voltage, the control unit contains a voltage switch-regulator, three delay elements, a high-frequency generator, a switch voltage level sensor A capacitor and four pulse drivers, with the voltage regulator switch made in the form of a transformer with an adjustable transformation ratio, the primary winding of which is located on the slide, the nominal frame with a constant winding pitch and connected to the output of the high-frequency generator, and three secondary windings are located On the common fixed frame and the conclusions of each of them are connected to the power terminals of the corresponding delay element, the first and second secondary windings are arranged in series in ol entire carcass winding step c length, a decreasing from left to right, and the winding length greater than the length of the primary winding and a third secondary winding is arranged along the entire length of the chassis with a winding pitch uvelichivayuschims left to right, the first and second delay elements have a common control input; connected to the output of the level sensor on the voltage on the switching capacitor, the output of the first and one of the outputs of the second delay element are connected to the control input of the third delay element, the other output of the second delay element is connected to the inputs of the first co and second pulse drivers, each of which connected to the control electrodes of the corresponding pair of series-connected thyristors of the bridge, and the output of the third delay element o is connected to the inputs of the third and fourth) form leu pulses, each output of which is connected to the gate electrodes corresponding diagonal bridge pair tiris- tori.

Description

The invention relates to electrical engineering, in particular to converter equipment, and a molset to be used to control the speed of the traction motors.

DC / DC converters are known that provide either frequency-pulse or pulse-width control; i and 2.

Of the famous converters. The closest technical solution is a DC / DC converter containing a regulating element connected between the input and output pins of a four-thyristor bridge in series with the input-filter. The switching capacitor and the control unit implementing it in the form of a bridge on four thyristors. pulse width control L2.

However, this converter has a relatively narrow range of regulation of the output voltage, so the shortest duration of the output pulses in it is limited by the recharging time of the switching capacitor and the own time of locking the thyristors.

The aim of the invention is to increase reliability and expand the range of output voltage control.

The goal is achieved by the fact that the control unit contains a voltage regulator switch, three delay elements, a high-frequency generator, and a level sensor. voltage on the switching capacitor and four pulse shapers, while the regulator switch is designed as a transformer with an adjustable transformation ratio, the primary winding of which is located on a moving frame with a constant step of winding and connected to the output of the high-frequency generator, and three secondary windings located on a common fixed frame and the conclusions of each of them are connected to the power terminals of the corresponding delay element, the first and second secondary windings are located They are consecutively along the entire length of the frame with a winding pitch decreasing from left to right and a winding length greater than the length of the primary winding, and a third secondary winding is located along the entire length of the frame with a winding pitch increasing from left to right, the first and second delay elements have common control input connected to the output of the voltage level sensor on the switching capacitor, the output of the first and one of the outputs of the second delay element are connected to the control input of the third delay element, the other output of the second The delay time is connected to the inputs of the first and second pulse shaper, the outputs of each one of which are connected to the control electrodes of the corresponding pair of series-connected thyristors of the bridge, and the output of the third delay element is connected to the inputs of the third and fourth pulse shapers, each output of which is connected to the control electrodes corresponding diagonal pair of thyristors of the bridge.

FIG. 1 shows a power circuit of a thyristor converter in FIG. 2 is a block diagram of a control system; FIG. 3 shows the combined scheme of the first and second delay terms, FIG. 4 shows the scheme of the third delay element; Fig. 5 shows the arrangement of the windings of the voltage regulator switch.

The power circuit includes an inductance 1 and a capacitance 2 of the input filter, the thyristors 3-6 of the power bridge, in the diagonal of which the switching capacitor 7 is switched on, the smoothing choke 8, the excitation winding 9 and the choke 10 of the motor, a check valve 11,

The block diagram of the converter control system includes a triggering gene; rator 12, a voltage level sensor 13 on a co-capacitor, the first delay element 14, a second delay element 15, a third delay element 16, drivers And v puls 17-20, a high-frequency generator 21 non-contact voltage regulator-switch 22,.

The first and second delay elements have capacitors 23 and 24, charged through resistors 25 and 26, and a common turn-on thyristor 27, whose control electrode is the common control terminal of elements 14 and 15 of smoothing filters consisting of resistors 28 and 29, capacitors 30 and 31, which in turn are connected to the outputs of rectifying bridges 32. and 33, the input terminals of which form the terminals for connecting the power supply of the elements 14 and 15,

In addition, there are thyristors 3 and 35, the control circuits of which are through zener diodes 36 and 37 and diodes 38 and 39 connected, to their anodes, transformers 40 and 34 and reset circuits and locking, consisting of diodes 42-44, thyristor 45, inductance dB and capacitor 47, the third delay element has a capacitor 48, charge through a resistor 49 and turn on the thyristor 50 from a smoothing filter consisting of a capacitor 51 and a resistor 52 connected through a distribution diode 53 to the output of the rectifier bridge 54, the thyristor 55, the control electrode which through the stabilizer it is 56 and the diode 57 is closed to the anode, the transformer 58, the locking circuit, consisting of capacitor 59, inductance 60, thyristor 61, and diodes 62 and 63. The high-frequency generator, whose power supply circuit is connected to any constant source, can be made according to any scheme (in particular, you can use a thyristor RC generator with anode control). A contactless voltage switch-regulator is a transformer, in which the transformation ratios between the primary winding and the three secondary windings are regulated by not shifting the primary winding relative to the secondary ones. The three secondary windings are located on one fixed frame, and the primary winding is located on the other — the movement of the frame. The first and second secondary windings are arranged successively one after the other from left to right along the entire length of the frame and the winding pitch of each winding of these windings is reduced from left to right. The third secondary winding is located under the first and second secondary windings along the entire length of the frame and its winding pitch increases from left to right. To the output of the high-frequency oscillator 21, a primary switching W of the voltage-switching regulator is connected. The first secondary winding W of the voltage regulating switch is connected via the rectifying bridge 32 to the power supply circuit of the first delay element, to the secondary winding H (/ 2 via the rectifying bridge 33 is connected to the third secondary winding W through rectifier bridge 54 is connected to the power supply circuit of the third delay element The control circuit of the common turn-on thyristor 27 of the first and second delay elements is connected to the output of the level sensor on the switching capacitor 13. The outputs of the first winding and a pulse transformer 40 of the first delay element is connected to a circuit (switching on the thyristor 50 of the third delay element and forming the output of the element 14, the second secondary winding of the pulse transformer 40 is connected to the control circuit of the common thyristor of locking 45 of the first and second delay elements). the transformer 41 of the second delay element is connected to the control circuit of the common thyristor of locking 45 of the first and second delay elements. The second secondary winding of the pulse transformer 41 is connected to the control circuit of the switching-on thyristor 50 of the third delay element and forms the first output of the element 15, and the third and fourth windings of the switching transformer 41 are connected to the control circuit of the thyristors of the switching of the pulse shaper 19 and 20 and form the second output of the element 15. The first and second secondary windings of the pulse transformer 58 of the third delay element are connected to the thyristors control circuits for switching on the pulse formers 17 and 18 and form the output element 16. The third secondary winding of the pulse transformer 58 is connected to the thyristor control circuit of the locking 61 of the third delay element. When voltage is applied to the input of the power circuit filter after reaching a predetermined voltage level on the capacitor 2, the starting generator 12, operating at a frequency less than the minimum operating frequency of the system, produces control pulses to the thyristors 3 and 5 of the power bridge. When the voltage on the cohp of the scrubbing capacitor reaches a level that provides the necessary switching capacity, the voltage level sensor 13 triggers and generates control pulses on the switching-on thyristor 27 of the first and second delay elements and on the starting generator blocking device . When the primary winding of the voltage-switching torus moves relative to the secondary one from left to right first (the supply voltage is fed from its windings to the first and the retium delay elements, the second delay element does not work. With further movement of the primary winding - the voltage regulator switch in the same direction, the supply voltage is fed from its windings to the second and third delay elements, the first delay element does not work. When triggered with an adjustable time delay, the first delay element triggers a pulse that opens the switching-on triangle 50 of the third delay element, simultaneously controlling the pulse. The thyristor locks 45 of the first and second delay elements to the thyristor and after recharging the capacitor 47 the switching-on thyristor 27 is locked, thereby closing the capacitors 23 and 24 of the first and second delay elements from the power source. With an adjustable time delay, the third delay element is triggered and sends a pulse to the thyristor of the locking device 61 and simultaneously issues control pulses to the driver of the pulses. and 18. The circuits feed all the pulse formers connected to the switching capacitor 7. At the polarity of the voltage indicated in FIG. 1, generates control pulses of the driver, 17 on the control circuits of the thyristors 3 and 5 of the power bridge, with reverse voltage, voltage pulses of the driver 18 on the control circuits of the thyristors 4 and b of the power bridge, thereby providing a reset of the switching capacitor 7. Change the response time of the first element is delayed. by adjusting the voltage level taken from the voltage regulator by moving its primary winding, the frequency-pulse regulation is performed at the first positions of the primary winding of the voltage regulator relative to the secondary ones, at the remaining positions of the primary the windings are relatively secondary, the second and third elements of the delay operate, and the first delay element does not work. When the second delay element is triggered, control pulses are applied to the thyristor locking 45 of the first and second delay elements, the switching-on thyristor 50 of the third delay element and simultaneously to the pulse conditioners 19 and 20. At the polarity of the voltage, the switching capacitor 7 shown in FIG. 1, pulse generator 19 is triggered and outputs control pulses to the thyristors 3 and 4 of the power bridge; when reversed, the pulse generator 20 is triggered and outputs control pulses to the thyristors 5 and 6 of the power bridge, thereby connecting the load directly to the input filter. Then, with adjustable time delay, a third delay element is emitted to the formers 17 and 18, which ensure recharging of the commutation capacitor 7 and locking of all four thyristors of the power bridge. Changing the response time of the second and third delay elements by moving the primary winding and the voltage-switching regulator, the pulse-width adjustment by the converter is carried out. When the primary winding and voltage regulator are moved from left to right relative to the secondary windings, the transformation ratio between the primary and first secondary windings and between the primary and third secondary windings first increases. The transformation ratio between the periodic and the second secondary winding increases insignificantly compared with the increase in the transformation ratio between the primary and the first secondary rfmotki, due to this, the voltage at the input of the first delay element is much greater than the voltage at the input of the second delay element, while the first delay element, and the second delay element does not work. The delay time of the first and third delay elements is reduced. Thus, the frequency-pulse control mode of the converter is carried out. With further movement of the primary winding relative to the secondary ones in the same direction, the transformation ratio between the primary and second toric windings begins to increase significantly, and the transformation ratio between the primary and first secondary windings changes significantly, thereby increasing the voltage at the input of the second delay element, than the voltage at the input of the first latch, the second is triggered. delay element, and the first delay element does not work. The transformation ratio between the primary winding and the third secondary winding continues to decrease smoothly. The delay time of the second delay element decreases, and that of the third delay element increases. Thus, the pulse-width adjustment mode of the converter is carried out. For normal operation of the circuit, it is necessary that when the first delay element triggers, the capacitor 24 of the second delay element is discharged and vice versa when the second delay element triggers, the capacitor 23 of the first delay element must be discharged. according to which

the capacitor 23 is discharged at the first delay element at the moment the second delay element is triggered, and at the moment the first delay element is fired, the capacitor 24 of the second delay element is discharged.

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/ T

with

The proposed thyristor converter favorably differs from the prototype and well-known thyristor converters, since the range of output voltage control is significantly expanded.

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FIG. five

Claims (1)

No. 1054186, class Н 02 М 3/14, 1963. 'A DC / DC converter to DC, - containing a control element connected in series between the input and output terminals in series with the input filter, made in the form of a bridge on four thyristors, the diagonal of which includes a switching capacitor and a control unit, from characterized in that, in order to expand the range of regulation of the output voltage, the control unit contains a voltage regulator-switch, three delay elements, a high-frequency generator, a voltage level sensor per comm a capacitor and four pulse shapers, while the voltage regulator-switch is made in the form of a transformer with an adjustable transformation coefficient, the primary winding of which is located on a movable frame with a constant step on the coils and connected to the output of a high-frequency generator, and three secondary windings are located on a common the fixed frame and the conclusions of each of them are connected to the power terminals of the corresponding delay element, the first and second secondary windings are arranged in series along the entire length of the frame with a winding step decreasing from left to right and the length of the winding longer than the length of the primary winding, and the third secondary winding is located along the entire length of the frame with the winding step increasing from left to right, the first and second delay elements have a common control input connected to the output of the voltage level sensor at the switching capacitor, the output of the first and one of the outputs of the second delay element are connected to the control input of the third delay element, the other output of the second delay element is connected the inputs of the first and second pulse shapers, the outputs of each of which are connected to the control electrodes of the corresponding pair of bridge thyristors connected in series, and the output of the third delay element is connected to the inputs of the third and fourth pulse shapers, · The output of each of which is connected to the control electrodes of the corresponding diagonal pair of thyristors bridge.