SU1605300A1 - Transformer-less variable a.c. to d.c. voltage converter - Google Patents

Abstract

The invention relates to electrical engineering and can be used as a transformerless power supply. The purpose of the invention is to simplify and increase reliability. The device consists of a voltage divider 3, connected through charging 4, 5 and bit 6, 7 thyristors between the output of rectifier 1 with filter 2 and through a DLC filter with a load circuit 10. Each of the thyristors 6, 7 is additionally bridged by a chain of series connected auxiliary charge 17 (19) and switching 18 (20) thyristors connected in the conducting direction. Switching capacitor 21 is connected between common points of thyristors of these chains. Parallel to the output of voltage divider 3, a chain of storage capacitor 11 and zener diode 12, shunted by primary winding 13 of pulse transformer 14, is connected. Secondary windings 15, 16 of this transformer are included in thyristor control circuits 6, 7 respectively. This design of the device ensures reliable galvanic isolation of the power supply network and load 10, as well as reliable operation of thyristors 4-7 by using a capacitor 11, a zener diode 12 and a pulse transformer 14, since the opening of thyristors 4, 5 and 6, 7 is excluded. 2 Il.

Description

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but zgipuptirovoy chain of series-connected auxiliary charge 17 (9) and commuting 18 (20) thyristors, included in the conducting direction. Between the common points of connection of the thyristors of these chains are switched to commute (u-1st capacitor 21, Parallel to the output of the voltage divider 3, the circuit is connected from the storage capacitor 1i and the zener diode 12, which is bridged by the primary winding 13 of the pulse

transformer 14; Secondary windings 15, 16 of this transformer are included in the thyristor control circuits 6.7, respectively. This design of the device ensures reliable galvanic isolation of the mains supply and 1 O load, as well as reliable operation of thyristors 4–7 due to the use of a capacitor 11, a zener diode 12 and a pulse transformer 14, since the simultaneous opening of thyristors .4,5 and 6,7 is excluded. 2 Il.

The invention relates to electrical engineering, in particular to adjustable power sources with transformerless conversion of alternating voltage to constant voltage.

The purpose of the invention is to simplify and increase reliability.

FIG. 1 shows the scheme of the proposed transformerless regulated converter of variable voltage to constant; in fig. 2 - stress diagrams, explaining the principle of operation.

The spheres of the mat or i-shsh r e gul and ru e converter converter (fig. 1) contain the rectifier: 1, filter 2 rectifier - t-voltage, diode-capacitor divider 3 voltage connected to rectifier filter 2 celler cherz first and second charge thyristors / 4 and 5 and through the first and second discharge thyristors b and 7 to the input C of the filter 8, the output of which is connected to the voltage sensor 9 and load 10. Parallel to the bottom-capacitor divider 3 are connected in series connected storage capacitor 1 and zener diode 12, the primary winding 13 is pulse The first transformer 14 is connected to the zener diode 12j and the secondary windings 15 and 16 of the pulse transformer 14 are connected respectively to the control elec- trons of the AM. The first and second discharge thyristors 6 and 7; Auxiliary charging and switching thyristors 17-20 are connected in pairs according to series and free power electrodes are connected in a conducting direction to discharge thyristors 6 and 7, and the plates are connected to their common points KONJ-mutating capacitor 21, outputs

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the thyristor control unit 22 is connected to the control electrodes of charge 4.5 and 18.20 switching thyristors, the input of the thyristor control unit 22 is connected to the output of the voltage sensor 9.

The transformerless variable voltage-to-constant converter operates as follows.

When the AC mains voltage is turned on, the thyristor control unit 22 generates a control pulse for the simultaneous opening of charge thyristors 4 and 5 and auxiliary thyristors 17 and 19, the series-connected capacitors of the same capacity of the single-capacitor voltage divider 3 are charged. 11 and kom-tiruyuschego 21 capacitors, at the end of their charge occurs a natural shutdown of auxiliary charge thyristors 17 and 19 and charge thyristors 4 and 5, which turn off the diode-condenser torny voltage divider 3 from the filter 2 rectifier. The voltage on the diode-capacitor voltage divider 3 abruptly (Fig. 2) decreases by a factor of n (n is the voltage division factor) due to a change in its structure — switching capacitors to parallel connection. In this case, the storage capacitor 11, charged to the output voltage and (Fig. 2) of the filter 2 of the rectifier, will be discharged through the paraplally connected Zener diode 12 and the primary winding 13 of the pulse. transformer 14, which will form a voltage on its secondary windings to turn on discharge thyristors 6 and 7.

A Zener diode 12 connected in the direction of stabilization for the discharge current of the storage capacitor 11 ensures the stabilization of the voltage on the primary winding 13. Thus, the opening of the discharge thyristors 6 and 7 can occur only after turning off the charge: x thyristors 4 and 5, which contributes the exclusion of the simultaneous opening of charge and discharge thyristors and the mains voltage on the subsequent power links, i.e., reliable electroplating, isolation of the supply mains and load 10, and, therefore, one of its The outputs can be grounded. Through discharge thyristors 6 and 7, the voltage reduced in. n times, it will be applied to the input of the DLC filter 8, and when it reaches the output of the set value from the output of the divider 9 voltage, the input of the thyristor control unit 22 will receive a signal which, after comparing it with the reference voltage, will be converted into triggering pulses to open the switching thyristors 18 and 20, which, when opened, apply the voltage of the switching capacitor 21 to the discharge thyristors 6 and 7 in the blocking direction. When the voltage is reduced at the load 10, the thyristor control unit 22 together with the voltage sensor 9 generates, the triggering impulses of charge thyristors 4 and 5, and then the process repeats.

Thus, in the scheme of the proposed device, due to the presence of a price

The feedback will be controlled (stabilized) on. load voltage 10.

Claims (1)

Formula IZ A transformerless variable voltage-to-constant voltage converter containing input and output terminals for connecting the supply network and load, respectively, a rectifier with a filter at the output connected by an input with input terminals, a diode-capacitor voltage divider, one output of which is connected to The positive output of the rectifier filter through the first charge thyristor and with one of the power electrodes of the first discharge thyristor, as well as the voltage sensor, is turned on-. “20 25 so 35 40 45 c g between the output pins, and the thyristor control unit, the outputs of which are connected to the control pods of the corresponding thyristors, distinguished by the fact that, in order to simplify and increase reliability, it is additionally equipped with a DLC filter, second charge and discharge one thyristor, two chains, each of which consists of auxiliary-connected charging and switching thyristors connected in series, switching and storage capacitors, a zener diode and a pulse transformer with one primary oh and two secondary windings, the second charge and discharge thyristors are connected in series and connected in the conductive direction between the second output terminal and the negative output of the filter and the other capacitor voltage divider connected to the common point of the second charge one and the other thyristors, to one of the conclusions of the chain, formed in series by connected storage capacitors and a zener diode, shunted by the primary winding of the transistor and the common connection point of the second discharge thyristor with the auxiliary charge thyristor is the second of these chains connected in the conducting direction parallel to the second loop of the discharge digit thyristor, the other output of the chain from the zener diode and the storage capacitor is connected to the common connection point of the first charging and discharge thyristors and auxiliary charge thyristor of the first of these chains, connected in the conducting direction parallel to the first discharge thyristor, between common connection points Auxiliary charging and switching thyristors of the above chains include a commutating capacitor, the input of the DLC filter is connected to the free terminals of the power electrodes, the first and second discharge thyristors, and its output is connected to the output terminals of the pulse transformer respectively included in the circuit control of the first and second discharge thyristors, and the control circuit of the second charge thyristor and auxiliary switching thyristors of the indicated chains of coupling with the corresponding additional FIG. g the outputs of the control unit, the input of which is connected to the output of the voltage sensor.