RU2358379C1 - Ac-to-dc voltage converter (versions) - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: invention deals with design of converter equipment; its implementation is to provide for conversion of three-phase ac voltage to 6-pulse or 12-pulse dc voltage at two rectifier diodes with the voltage thyristor-regulated on the group transformer input side. Under the first (6-pulse) design version the converter comprises two single-phase transformers, an additional pair of controllable gates, connected in parallel opposite and a secondary winding. One end of each single-phase transformer primary winding is connected to the phase input terminal and the other - to the common point of the controllable gate pair connected in parallel opposite; via the said common point the primary winding is connected to the opposite input terminal. The common points of the controllable gates serve to close the series circuit composed of all the gates specified and one of the primary windings. The secondary winding central and end outputs are connected to a double-diode rectifier. The secondary winding common cavity contains one core with each transformer's primary winding. Specificity of the second version (12-pulse) converter consists in it comprising four additional pairs of the aforesaid type gates and two additional primary windings, one of them applied on one transformer and the other, with a

-fold greater number of coils - on the other. The winding are connected via the corresponding gate pairs, the major - between the phase and the zero input terminals, the minor - between the phase input terminals. Each main primary winding contains an intermittent terminal that breaks down its total number of coils at a ratio of

with the major portion counted from the loose phase input terminal. The intermittent terminal is connected to the zero input terminal via a corresponding gate pair. The both design versions allow of usage of a varied design homotypic magnetic circuit pair including a two-limb core with sectioned primary and secondary windings. The third (6-pulse) converter design version differs from the first one due to it envisaging additional embedment of an identical single-phase transformer restricting the diversity of magnetic circuits used; all the three primary windings alongside with the controllable gates (joined in parallel opposite) delta-connected with the delta vertices linked to the phase input terminals. With regard to a 12-pulse converter design the third version envisages each primary winding having an intermittent terminal that breaks down its total number of coils at a ratio of

and connected to the zero input terminal via the aforesaid additional gate pair.

EFFECT: conversion process simplification combined with improved current usage at uniform distribution of current between the rectifier diodes.

16 cl, 8 dwg

Description

The invention relates to a conversion technique and can be used to convert a three-phase AC voltage to a constant, 6-pulse or 12-pulse, on two rectifying diodes when regulating the voltage with thyristors on the primary side of a group transformer.

All of the following analogues are analogues for all variants of the proposed Converter.

The AC-to-DC converter is widely known, comprising a single-phase rod-type transformer with a primary winding consisting of two sections located on different rods and connected in parallel to the input terminals, with two secondary windings consisting of each of two sections connected in opposite series and placed on different rods, the common point of one pair of the same terminals of which is connected to the first output of the load, and each output of another pair of the same terminals is connected to the anode an ode whose cathode is connected to the second output terminal of the load (see Kaganov I.L. Electronic and ionic converters. Part 3. 1956, p. 36 (two-phase rectification in the circuit with zero output at active load).

The circuit of this converter illustrates the possibility of converting a single-phase alternating voltage to constant on two diodes and a rod-type transformer with parallel and sequentially sectioned windings. The converter does not provide increased rectification frequency.

The set of reasons that impede the achievement of the required technical result is that its purpose is limited only by the possibility of converting a single-phase alternating voltage into alternating and / or constant, 2-pulse.

A known converter of alternating voltage to DC, containing a transformer, the primary and secondary three-phase windings of which are connected in a star, three valves connected to the free terminals of the secondary winding and the combined electrodes forming the first output terminal, an additional winding, one terminal of which is connected to the neutral of the star of the secondary winding, and the other forms a second output terminal, the transformer magnetic circuit is made with a gap for the fluxes of forced magnetization, an additional winding covering a three shaft transformer, said one is the start of its output and the other - the end (see AS №1328903, Cl H02M 7/06, 22.02.85..).

The disadvantage of this converter is that it does not provide increased rectification frequency on two diodes.

The set of reasons that impede the achievement of the required technical result is that the additional winding performs only compensation functions associated with the flow of only the zero sequence current in it, i.e. depending on the direction of its connection, it can either compensate the forced magnetization flux or suppress the ripple of the rectified voltage by a certain amount. It is unsuitable for converting the fundamental harmonics of voltage.

A known converter of three-phase AC to DC, containing two single-phase transformers with secondary windings connected to the inputs of single-phase rectifiers, the outputs of which are connected in parallel, forming a rectifier with the number of valves multiple of four, with two primary phase windings connected by intermediate terminals dividing the turns of each of them into equal parts, to the terminals of the first pair of counter-parallel-connected controlled valves, one pair of opposite extreme terminals of both windings - to opposite phase input terminals, and another pair of opposite extreme terminals - to the terminals of the second and third pairs of counter-parallel connected controlled valves, the free terminals of which are connected to a free phase input terminal (see AS No. 1457124, class Н02М 7 / 17, 06/01/08).

The disadvantage of this converter is the need for four diodes on the secondary side and an intermediate terminal in each primary phase winding, dividing it into equal parts for uniform distribution of the rectified current on the diodes. In addition, the conduction angle of each diode is only 120 el. hail.

The set of reasons that impede the achievement of the required technical result is that four out of six thyristors, pairwise connected to the primary winding of one of the transformers, do not have a control effect on the diodes connected to the secondary winding of another transformer.

части их витков, отсчитываемых от указанных фазных входных выводов, - к первому двухполюснику, а другой парой крайних выводов через второй и третий двухполюсники - к нулевому входному выводу, с двумя вторыми соответственно встречно или согласно-последовательно включенными первичными фазными обмотками, образующими с четвертым двухполюсником последовательную цепь, включенную между нулевым входным выводом и общей точкой пятого и шестого двухполюсников, с двумя третьими первичными фазными обмотками, третьи первичные фазные обмотки соединены соответственно встречно или согласно-последовательно и включены между третьим фазным входным выводом и общей точкой пятого и шестого двухполюсников, свободные выводы которых подключены соответственно к второму и третьему двухполюсникам, причем соотношение чисел витков первой и третьей первичных обмоток равно

(см. а.с. №1580508, кл Н02М 7/17, 11.01.88. Недостатком этого преобразователя является необходимость четырех первичных обмоток на каждом однофазном трансформаторе и четырех диодов, т.е. сложность. Кроме того, угол проводимости каждого диода равен всего 120 эл. град.A known Converter of three-phase AC to DC, containing six two-terminal, made in the form of counter-parallel connected controlled valves, two single-phase transformers with secondary phase windings connected to the inputs of single-phase rectifiers, the outputs of which are connected in parallel, forming a rectifier with the number of valves that are a multiple of four, with two first primary phase windings connected by one pair of opposite or similar extreme terminals of both windings to two phase input m conclusions from intermediate terminals

parts of their turns, counted from the indicated phase input terminals, to the first two-terminal device, and another pair of extreme terminals through the second and third two-terminal devices to the zero input terminal, with two second primary phase windings opposite or sequentially connected, forming with the fourth two-terminal device a serial circuit connected between the zero input terminal and the common point of the fifth and sixth bipolar, with two third primary phase windings, the third primary phase windings connected They are respectively counterclockwise or in series, and are connected between the third phase input terminal and the common point of the fifth and sixth two-terminal networks, the free terminals of which are connected respectively to the second and third two-terminal networks, and the ratio of the number of turns of the first and third primary windings is

(see AS No. 1580508, class Н02М 7/17, January 11, 1998. The disadvantage of this converter is the need for four primary windings on each single-phase transformer and four diodes, i.e. complexity. In addition, the conductivity angle of each diode is total 120 electric city

The set of reasons that impede the achievement of the required technical result is that four of the twelve thyristors, pairwise connected to the primary winding of one of the transformers, do not have a control effect on the diodes connected to the secondary winding of another transformer.

By additional auto No. 860238, cl. Н02М 7/12 from 08/02/79 to the main bus station No. 752681, cl. H02M 7/06, 02/04/76, a three-phase AC to DC converter is known, comprising a three-phase transformer, the primary windings of which together with the pairs of counter-parallel-connected controlled valves connected in series with them form a star connected to the phase input terminals, and the secondary windings connected to a star and connected to a rectifier bridge, while a set of secondary windings, a rectifier bridge and controlled valves are additionally introduced, moreover, the primary windings through supplement The oncoming parallel-parallel valves are connected to the zero input terminal, and an additional set of secondary windings and an additional rectifier bridge, together with the main secondary windings and the main rectifier bridge, are connected according to the twelve-pulse rectifier circuit, an additional three-phase transformer is introduced, the primary windings of which are connected to a star, a common point which is connected to the zero input terminal, and the group of secondary windings is connected in a triangle.

This converter illustrates the ability to connect to an artificial zero input terminal formed by the neutral of the winding of an additional transformer connected to a star and connected to the phase input terminals.

Its disadvantage is the need for 12 diodes, i.e. complexity, as well as the inequality of the conduction angles of the diodes of the main (90 electric grad.) and additional (30 electric grad.) bridges.

The set of reasons that prevent the desired technical result from being obtained is that the secondary winding of the main three-phase transformer is connected to a star.

The closest technical solution (prototype) is an AC to DC converter containing three single-phase transformers, the primary windings of which are connected to the main and additional pairs of counter-parallel connected valves, additional pairs of these valves are connected to a star, the common point of which is connected to the zero input terminal and the secondary windings are connected to the inputs of single-phase rectifiers, the outputs of which are connected in parallel, forming a rectifier with the number of valves multiple of w Each primary winding is made with a tap connected to the free terminal of the corresponding additional pair of counter-parallel connected valves, the beginning of each specified coil through the corresponding main pair of counter-parallel connected valves is connected to the output terminal, and the end of this winding is connected to the beginning of the leading phase winding wherein said tap from the primary winding divides its turns in relation to

where w ₁ is the number of turns from the beginning of the primary winding to the tap;

w ₂ - the number of turns from the tap to the end of the primary winding.

(see AS No. 995239, class Н02М 7/12 dated 03.24.81).

The disadvantage of this converter is the need for 6 diodes, i.e. complexity. In addition, the conduction angle of each diode is only 60 el. hail.

The set of reasons that prevent the desired technical result from being obtained is that the secondary winding of a three-phase transformer is connected to a three-phase group. The contradiction lies in the fact that during the operation of the device all three phase voltages of this winding (each for 120 electrical degrees) and, accordingly, six diodes to which it is connected must be involved, although not simultaneously.

The task to which the proposed technical solution is directed is to simplify the design by creating a three-phase AC to DC, 6-pulse or 12-pulse converter, rectifying on two diodes when regulating the voltage with thyristors on the primary side of the group transformer.

This problem in the first embodiment of the present invention is solved in that in an AC to DC converter containing two single-phase transformers with primary and secondary windings, for example, sectioned, each primary connected with one output to the first common point of the main counter-parallel connected controlled valves, the second the common point of which is connected to the phase input terminal, and the free terminal directly to the input terminal of the adjacent phase, with additional counter-parallel controlled valves connected by the first common point to the extreme terminal of one primary winding, two secondary windings, one pair of opposite terminals of which forms a common terminal, and the other is connected to the same electrode diodes connected by another pair of electrodes to the first output terminal, the second output terminal, in any cavity formed by the secondary winding, there is one rod with the primary winding of each transformer, the second common point of additional controlled valves is connected to the corresponding he concluded circuit containing a pair of basic together with controlled valves another primary winding, and closes the series circuit, consisting of all controlled valves and one of the primary windings, and the total output of secondary winding connected to the second output terminal.

The core of each transformer can be wound from a steel strip and have a ring shape in longitudinal section, and the rods of both transformers are placed in the common cavity of the secondary windings.

Each transformer winding can consist of two sections located on different rods of a 2-core magnetic circuit, and one rod with a primary winding section of each transformer is placed in the cavity of each section of the secondary winding.

The primary windings of each transformer can be made on the middle rod of a 3-rod flat magnetic circuit, and the middle rods of both transformers are placed in the common cavity of the secondary windings.

The primary windings of each transformer can be made on one rod of a 2-rod magnetic circuit, and the indicated rods of both transformers are placed in the common cavity of the secondary windings.

отсчитываемом от первого крайнего вывода, к первым общим точкам встречно-параллельно включенных управляемых вентилей, вторые общие точки которых соединены соответственно с входным выводом смежной фазы и нулевым входным выводом, третьей первичной обмоткой, подключенной аналогично первым двум крайними выводами к соответствующим фазным входным выводам, двумя вторичными обмотками, одна пара разноименных выводов которых образует общий вывод, а другая подключена к одноименным электродам диодов, соединенных другой парой электродов с первым выходным выводом, второй выходной вывод, дополнительные встречно-параллельно включенные управляемые вентили, в любой полости, образованной вторичной обмоткой, размещен один стержень с первичной обмоткой каждого трансформатора, общий вывод вторичных обмоток подключен ко второму выходному выводу, третья первичная обмотка выполнена на одном трансформаторе, а на другом - дополнительная первичная обмотка, с числом витков, равным числу витков основной между первым крайним и промежуточным выводами, подключенная одним выводом к первому крайнему выводу третьей первичной обмотки, а другим - к первой общей точке упомянутых дополнительных вентилей, вторая общая точка которых соединена с нулевым входным выводом.In the second embodiment of the invention, this problem is solved in that in an AC to DC converter, containing two single-phase transformers with primary and secondary windings, for example, sectioned, each primary connected by the first extreme terminal to the phase input terminal, and the second extreme terminal and intermediate terminal dividing its number of turns in relation

counted from the first extreme terminal, to the first common points of the on-parallel connected controlled valves, the second common points of which are connected respectively to the input terminal of the adjacent phase and the zero input terminal, the third primary winding connected similarly to the first two extreme terminals to the corresponding phase input terminals, two secondary windings, one pair of opposite terminals of which forms a common terminal, and the other is connected to the same electrode diodes connected by another pair of electrodes from the first m output terminal, second output terminal, additional counter-parallel controlled valves, in any cavity formed by the secondary winding, there is one rod with the primary winding of each transformer, the common output of the secondary windings is connected to the second output terminal, the third primary winding is made on one transformer and on the other - an additional primary winding, with the number of turns equal to the number of turns of the main between the first extreme and intermediate terminals, connected by one terminal to the first edge it third terminal of the primary winding and the other - to the first common point of said additional rectifiers, the second common point which is connected to the zero input terminal.

The core of each transformer can be wound from a steel strip and have a ring shape in longitudinal section, and the rods of both transformers are placed in the common cavity of the secondary windings.

Each transformer winding between its adjacent terminals can consist of two sections located on different rods of a 2-core magnetic circuit, and one rod with a primary winding section of each transformer is placed in the cavity of each section of the secondary winding.

The windings of each transformer can be made on the middle rod of a 3-rod flat magnetic circuit, and the middle rods of both transformers are placed in the common cavity of the secondary windings.

The windings of each transformer can be made on one rod of a 2-core magnetic circuit, and the indicated rods of both transformers are placed in the common cavity of the secondary windings.

The converter may contain an additional transformer, the primary winding of which is connected to a "star" and connected by one of the conclusions and the common point of the other conclusions, respectively, to the phase and zero input terminals.

In the third embodiment of the invention, this problem is solved in that in an AC / DC converter containing three single-phase transformers, with primary windings, each connected by one output to the first common point of the on-parallel-connected controlled valves, the second common point of which is connected to the phase input output, and a free output - directly to the input output of the corresponding adjacent phase, two secondary windings, one pair of opposite terminals of which forms a common water, and the other is connected to the like electrodes of diodes connected in another pair of electrodes to a first output terminal, the second output terminal of the secondary winding form a common cavity in which is placed a rod with a primary winding of each transformer, and the total output of secondary winding connected to the second output terminal.

, большая из которых отсчитывается от упомянутого свободного входного вывода, и подключенный к одному выводу соответствующей дополнительно введенной пары встречно параллельно включенных управляемых вентилей, другой вывод которой соединен с нулевым входным выводом.In addition, the primary winding of each transformer may contain an intermediate terminal dividing it into parts with respect to

most of which are counted from the aforementioned free input terminal, and connected to one terminal of the corresponding additionally introduced pair of counter-parallel controllable gates, the other terminal of which is connected to the zero input terminal.

The core of each transformer can be wound from a steel strip and have a ring shape in longitudinal section, and the rods of three transformers are placed in the common cavity of the secondary windings.

The windings of each transformer can be made on one rod of a 2-core magnetic circuit, and in the common cavity of the secondary windings the indicated rods of three transformers are placed with the possibility of mutual spatial shift.

The converter may contain an additional transformer, the primary winding of which is connected to a "star" and connected by one of the conclusions and the common point of the other conclusions, respectively, to the phase and zero input terminals.

The technical result achieved in all versions of the proposed is to simplify, namely: the possibility of converting a three-phase AC voltage to a constant, 6-pulse or 12-pulse, on two rectifying diodes with a conduction angle of each of them of 180 el. city., i.e. with better current usage with uniform distribution of the latter between them.

An additional technical result achieved in the first embodiment of the proposed relative to the above analogue (A.S. No. 1457124) is the lack of intermediate leads of the primary windings of the transformers.

An additional technical result achieved in the second version of the proposed relative to the above analogue (A.S. No. 1580508) is to reduce the number (three windings, taking into account taps, instead of four) of the primary windings of the transformers.

Figure 1 shows a schematic diagram of a first embodiment of a three-phase AC to DC converter on twisted tape magnetic circuits of toroidal transformers; figure 2 - the same, on 2 - core magnetic circuits with windings, divided into sections connected on the primary side in parallel, and on the secondary in pairs; figure 3 is the same, on a 2-rod magnetic circuits with windings divided into sections connected in series on the primary side and in parallel in parallel on the secondary side; figure 4 is the same on the middle rods of the 3-core magnetic cores; figure 5 is the same, on one of the rods of two 2-rod magnetic cores; Fig.6 is a schematic diagram of a second embodiment of a three-phase AC to DC converter with a conventionally axonometric image of the secondary winding, providing for the design of transformers similar to those indicated for the first embodiment; 7 is a schematic diagram of a third embodiment of a three-phase AC to DC, 12-pulse converter on twisted tape magnetic circuits of toroidal transformers; on Fig - the same, for the case of 6-pulse rectification.

The Converter in figure 1 contains counter-parallel connected pairs of thyristors, respectively 1 and 2, 3 and 4, 5 and 6, transformers made on twisted tape magnetic circuits 7, 8 with primary windings 9, 10 and a common secondary winding 11, respectively, in the cavity which contains the indicated magnetic cores. The beginning (end) of the secondary winding 11 is connected to the anode of the diode 12 (13), and a load 14 is connected between the common point of the cathodes of the diodes 12, 13 and the middle terminal of the winding 11. The end (beginning) of the winding 10 (9) is connected to the input terminal of phase A ( C), and the beginning (end) - to the common point of thyristors 1 and 2 (3 and 4), the other common of which is connected to the input terminal of phase B. Thyristors 5 and 6 are connected between the ends of the windings 9, 10.

Suppose that thyristor 1 is open from the line voltage applied to it between the input terminals of phases A and B. The current of the primary winding 10 of transformer 8 flows through the circuit: input terminal of phase A, from the end to the beginning of winding 10, from the anode to the cathode of thyristor 1, input the output of phase B. The current of the common secondary winding 11 of the transformers 7 and 8 flows through the circuit: the end of the winding 11, from the anode to the cathode of the diode 13, load 14, the middle output of the winding 11, i.e. one half of the winding 11 conducts a load current 14, and the other remains de-energized.

After 60 email deg., when the potential of phase C becomes more negative than the potential of phase B, thyristor 5 is unlocked from the line voltage applied to it between the phase input terminals A and C, and reverse voltage is applied to thyristor 1 and the current of the primary winding 9 of transformer 7 flows through the circuit : the input terminal of phase A, from the anode to the cathode of the thyristor 5, from the end to the beginning of the winding 9, the input terminal of phase C. The current of the common secondary winding 11 of the transformers 7 and 8 continues to flow along the same circuit through the diode 13, forming the next ripple in phase, because the direction of the magnetic flux relative to the secondary winding does not change.

Then through 60 email. deg., when the potential of phase B becomes greater than the potential of phase A, thyristor 3 is unlocked from the line voltage applied to it between the phase input terminals B and C, and reverse voltage is applied to thyristor 5 and the current of the primary winding 9 of transformer 7 flows through the circuit: the input terminal of phase B, from the anode to the cathode of the thyristor 3, from the end to the beginning of the winding 9, the input terminal of phase C. The current of the common secondary winding 11 of the transformers 7 and 8 again continues to flow through the same circuit through the diode 13, forming a phase-ripple.

In the next interval of discreteness, the potential of phase A becomes more negative than the potential of phase C, thyristor 2 is unlocked from the line voltage applied to it between the input terminals of phases B and A, and reverse voltage is applied to thyristor 3 and the current of the primary winding 10 of transformer 8 flows through the circuit : input terminal of phase B, from the anode to the cathode of thyristor 2, from the beginning to the end of the winding 10, input terminal of phase A. At the same time, the potential of the anode relative to the cathode of diode 12 becomes greater than that of diode 13, and the latter is locked. This is explained by the fact that the direction of the magnetic flux relative to the common secondary winding 11 changes its sign. The voltage that is transformed into the winding 11 also changes its sign, as a result of which the switching process occurs between the diodes 13 and 12. In the process of turning off the thyristor 3, the differential switching voltage between the lagging and leading half-waves of the linear voltage is transformed, which is applied to the turning off diode 13 in the opposite direction, and to turn on the diode 12 in the forward direction. The locking of the diode 13 de-energizes the thyristor 3 from the load current and the voltage at the load 14 generated by the open diode 12 rises to the nominal value. Now the current of the common secondary winding 11 of the transformers 7 and 8 flows through the other half of the circuit: the beginning of the winding 11, from the anode to the cathode of the diode 12, load 14, the middle output of the winding 11. Next, the diode 12, similar to the above, conducts current for two more cycles, then again, due to a change in the direction of the magnetic flux, diode 13 comes into operation. Thus, switching of thyristors and diodes, taking into account the change in the direction of the magnetic flux relative to the secondary winding, occurs with a frequency of 50 Hz. Due to the half-wave rectification scheme on the secondary side of the converter, the increase and decrease of the secondary currents during the switching of the diodes occurs, despite the common secondary winding, in different circuits, one of which is in a previously de-energized state.

раз превышает расчетную мощность обмотки 10. Однако это не нарушает равенства углов проводимости во вторичной цепи, т.е. угол проводимости каждого диода и вторичной полуобмотки равен 180 эл. град.Thyristors and diodes form a rectified voltage at load 14 with a frequency of m = 6 in the following sequence: 5-13, 1-13, 3-13, 2-12, 6-12, 4-12. The conduction angle of the primary winding 9 (10) is 240 (120) el. Therefore, the rated power of the winding is 9 v

times the rated power of the winding 10. However, this does not violate the equality of the conduction angles in the secondary circuit, i.e. the conduction angle of each diode and the secondary half-winding is 180 e. hail.

It should be noted that in the converter circuit of Fig. 1, thyristors 1 and 2, without changing the principle of operation, can similarly form a serial circuit with winding 10 even if they are interchanged, i.e. connect the beginning of winding 10 to the input terminal of phase B, and turn on thyristors 1 and 2 between the end of winding 10 and the common point of thyristors 5 and 6.

раз превышает расчетную мощность обмотки 9. Во всех случаях должна образовываться замкнутая последовательная цепь, содержащая все тиристоры и одну из первичных обмоток (например, обмотку 10 на фиг.1).In addition, in the converter circuit of FIG. 1, thyristors 5 and 6 can be turned on, without making changes to the connections of other elements, not between the ends, but between the beginning of the windings 9 and 10. In this case, the thyristors 3 and 4, without changing the principle of operation can similarly form a series circuit with a winding 9 and if they are interchanged, i.e. the end of the winding 9 is connected to the input terminal of phase B, and thyristors 3 and 4 are connected between the beginning of the winding 9 and the displaced common point of the thyristors 5 and 6. The difference between the second case of reconnecting the thyristors from the first is only in that the rated power of the winding 10 is now

times the calculated power of the winding 9. In all cases, a closed series circuit must be formed containing all thyristors and one of the primary windings (for example, winding 10 in figure 1).

The Converter according to figure 2 is characterized in that it is made on two two-core magnetic cores. The primary windings 9 and 10 are each divided into two sections located on different transformer rods 7 and 8, respectively, and connected relative to the supply voltage in parallel with such a connection of their beginnings and ends, which ensures a consistent direction of magnetic fluxes in each magnetic circuit, namely: the beginning (end ) of one section of the primary winding of each magnetic circuit is connected to the end (beginning) of its other section, and the corresponding linear voltage through the thyristors is connected to the terminals of each section.

Each half-winding of the secondary winding 11 between one of its extreme and middle terminals is also divided into two sections connected relative to the magnetic fluxes of the magnetic cores with such a connection of their beginnings and ends that provides summation of the voltage of the sections, while in the cavity of each section of the secondary winding there is one rod with section of the primary winding of each transformer, namely: the beginning of both sections of each half-winding are connected to each other, the end of one extreme section of the winding 11 is connected to the anode of the diode 12, and the end of the other goy - with the anode of the diode 13, between them and the ends of the cathodes secondary winding sections 11, 14 connected to the load.

Suppose that thyristor 1 is open and the linear voltage between the phase input terminals A and B is applied in parallel to the beginning (end) of one and to the end (beginning) of another section of the primary winding 10 on the magnetic circuit 8. Under the action of the secondary voltage, the load current flows from the beginning to the end the lower section of the lower half-winding of the winding 11, the anode of the diode 13, the load 14, from the end to the beginning of the upper section of the lower half-winding 11. In this interval of discreteness, the diode 12 is closed by reverse voltage applied to it by the upper sections of the upper half-winding 1 1. With the same direction of winding the sections of all windings, the coincidence of the polarity of their beginnings and ends is associated with the direction of the bypass of the rods with magnetic flux. The switching of diodes 12 and 13 between adjacent discrete intervals occurs when the polarity of the voltage changes between the sections of the upper and lower half windings 11. The tendency to inequality of currents in the parallel sections of the primary windings is counteracted by the serial connection of the sections of the secondary windings.

The Converter in figure 3 differs from the Converter in figure 2 only in that the sections of the primary windings 9 and 10 are connected to each other in series, and the secondary half windings 11 in parallel. The operation of the converter of FIG. 3 occurs similarly to that described for FIG. 2, and the series connection of the primary winding sections counteracts the current inequality in the parallel sections of the secondary half-windings supplying each diode.

The Converter in figure 4 differs from the Converter in figure 1 only in that it is made on the middle rods of two three-rod flat magnetic cores. There are no differences in their work. However, the design of the transformers is less convenient.

The Converter in figure 5 differs from the converters in Figs. 1 and 4 only in that it is made on one of the two rods of two two-core magnetic cores. There are no differences in their work. This design is simpler than in figure 2 and 3, however, with the same rated power requires higher rods.

, отсчитываемом от конца обмотки 10 (9). Число витков обмотки 15 равно большей части числа витков обмотки 9 или 10, а число витков обмотки 16 равно числу витков всей обмотки 9 или 10. Преобразователь содержит дополнительный маломощный трехфазный трансформатор 17, обмотка которого соединена в звезду и подключена концами к фазным входным выводам А, В, С, а общей точкой начал образует искусственный нулевой входной вывод 0. Кроме того, преобразователь дополнительно содержит встречно параллельно соединенные пары тиристоров соответственно 18 и 19, 20 и 21, 22 и 23, подключенные соответственно одной общей точкой к промежуточному выводу обмотки 10, к промежуточному выводу обмотки 9, к началу обмотки 15, а другой - к нулевому входному выводу 0. Концы обмоток 15 и 16 соединены с входным выводом фазы В, а начало обмотки 16 - с общей точкой тиристоров 5 и 6, другая общая точка которых подключена к входному выводу фазы А.The Converter in Fig.6 contains counter-parallel connected pairs of thyristors, respectively 1 and 2, 3 and 4, 5 and 6, transformers, for example, on twisted tape magnetic circuits 7, 8 with primary windings 9, 10 and a common secondary winding 11, respectively the cavity of which are located the indicated magnetic cores. The beginning (end) of the secondary winding 11 is connected to the anode of the diode 12 (13), and a load 14 is connected between the common point of the cathodes of the diodes 12, 13 and the middle output of the winding 11. The end of the winding 10 (9) is connected to the input terminal of phase A (C), and the beginning is to the common point of thyristors 1 and 2 (3 and 4), the other common of which is connected to the input terminal of phase C (B). On the transformer 8 (7), the primary winding 15 (16) is additionally made, and the primary winding 10 (9) contains an intermediate terminal dividing it with respect to

counted from the end of the winding 10 (9). The number of turns of the winding 15 is equal to most of the number of turns of the winding 9 or 10, and the number of turns of the winding 16 is equal to the number of turns of the entire winding 9 or 10. The converter contains an additional low-power three-phase transformer 17, the winding of which is connected to a star and connected by ends to the phase input terminals A, B, C, and a common point of origin forms an artificial zero input terminal 0. In addition, the converter additionally contains counter-paired pairs of thyristors, respectively 18 and 19, 20 and 21, 22 and 23, connected respectively to one a common point to the intermediate output of the winding 10, to the intermediate output of the winding 9, to the beginning of the winding 15, and the other to the zero input terminal 0. The ends of the windings 15 and 16 are connected to the input terminal of phase B, and the beginning of the winding 16 to the common point of thyristors 5 and 6, another common point of which is connected to the input terminal of phase A.

Suppose that the thyristor 22 is open from the phase voltage applied to it between the input terminals 0 and B. The current of the primary winding 15 of the transformer 8 flows through the circuit: zero input terminal, from the anode to the cathode of the thyristor 22, from the beginning to the end of the winding 15, the input phase output B. This current is the sum of equal in magnitude and phase-matched (branched) phase currents of the transformer winding 17, flowing in this discrete interval from its ends, connected to the input terminals of phases A, B, C to a common point 0 of its beginnings. The current of the common secondary winding 11 of the transformers 7 and 8 flows through the circuit: the end of the winding 11, from the anode to the cathode of the diode 12, load 14, the middle terminal of the winding 11, i.e. one half of the winding 11 conducts a load current 14, and the other remains de-energized.

раз больше фазного, то и прикладывается оно к числу витков обмотки 16, в

раз большему числа витков обмотки 15. К тиристору 22 прикладывается обратное напряжение между входными выводами А и 0, а ток первичной обмотки 16 трансформатора 7 протекает по цепи: входной вывод фазы А, от анода к катоду тиристора 6, от начала к концу обмотки 16, входной вывод фазы В. Ток общей вторичной обмотки 11 трансформаторов 7 и 8 продолжает протекать по цепи той же полуобмотки через диод 12, формируя следующую по фазе пульсацию, т.к. направление магнитного потока относительно вторичной обмотки не изменяется со сменой магнитопровода, пронизываемого этим потоком.After 30 email hail. thyristor 6 is unlocked from the line voltage applied to it between the input terminals of phases A and B. line voltage in

times more than phase, then it is applied to the number of turns of the winding 16, in

times the number of turns of the winding 15. A reverse voltage is applied to the thyristor 22 between the input terminals A and 0, and the current of the primary winding 16 of the transformer 7 flows through the circuit: the input terminal of phase A, from the anode to the cathode of the thyristor 6, from the beginning to the end of the winding 16, phase B input terminal. The current of the general secondary winding 11 of transformers 7 and 8 continues to flow along the circuit of the same half winding through diode 12, forming the next ripple in phase, because the direction of the magnetic flux relative to the secondary winding does not change with the change of the magnetic circuit penetrated by this flux.

раз меньше линейного, то и прикладывается оно к числу витков обмотки 10, в

раз меньшему числа витков обмотки 16. Ток первичной обмотки 10 протекает по цепи: входной вывод фазы А, от конца к промежуточному выводу части обмотки 10 с большим числом витков, от анода к катоду тиристора 19, искусственный входной вывод 0 соединенной в звезду обмотки трансформатора 17, далее разветвляется на три равные части, протекающие от общей точки начал к концам этой звезды и затем к соответствующим фазным входным выводам А, В, С. Направление результирующего магнитного потока относительно общей вторичной обмотки 11 изменяет свой знак. В связи с тем, что тиристор 6 в рассматриваемом коммутационном интервале остается включенным, это приводит к трансформированию в обмотку 11 разностного коммутационного напряжения между отстающей и опережающей равными по амплитуде полуволнами соответственно линейного и фазного напряжений, которое прикладывается к выключающемуся диоду 12 в обратном направлении, а к включающемуся диоду 13 в прямом направлении. Запирание диода 12 обесточивает от нагрузочного тока тиристор 6 и напряжение на нагрузке 14, формируемое открытым диодом 13, возрастает до номинального значения. Теперь ток общей вторичной обмотки 11 трансформаторов 7 и 8 протекает через другую ее половину по цепи: конец обмотки 11, от анода к катоду диода 13, нагрузка 14, средний вывод обмотки 11.Further through 30 email. hail. thyristor 19 is unlocked from the phase voltage applied to it between the input terminal of phase A and the zero input terminal 0. Since phase voltage in

times less than linear, then it is applied to the number of turns of the winding 10, in

times less than the number of turns of the winding 16. The current of the primary winding 10 flows through the circuit: the input terminal of phase A, from the end to the intermediate terminal of the part of the winding 10 with a large number of turns, from the anode to the cathode of the thyristor 19, the artificial input terminal 0 connected to the star of the transformer winding 17 , then branches into three equal parts flowing from the common point of the beginnings to the ends of this star and then to the corresponding phase input terminals A, B, C. The direction of the resulting magnetic flux relative to the common secondary winding 11 changes its sign. Due to the fact that the thyristor 6 remains switched on in the considered switching interval, this leads to the transformation into the winding 11 of the difference switching voltage between the lagging and leading equal-amplitude half-waves, respectively, of the linear and phase voltages, which is applied to the turning off diode 12 in the opposite direction, and to turn on the diode 13 in the forward direction. The locking of the diode 12 de-energizes the thyristor 6 from the load current and the voltage at the load 14 generated by the open diode 13 rises to the nominal value. Now the current of the common secondary winding 11 of transformers 7 and 8 flows through its other half along the circuit: the end of the winding 11, from the anode to the cathode of the diode 13, load 14, the middle terminal of the winding 11.

Then after another 30 email. hail. thyristor 2 is unlocked from the line voltage applied to it between the input terminals of phases A and C, and reverse voltages are applied to the thyristors 19 and 6 between input terminals 0, C and C, B. Current of the primary winding 10 flows through the circuit: input terminal of phase A , from the end to the beginning of the winding 10, from the anode to the cathode of the thyristor 2, the input terminal of phase C. The current of the general secondary winding 11 of the transformers 7 and 8 continues to flow through the circuit of the same half winding through the diode 13, forming the next phase ripple, because the direction of the magnetic flux relative to the secondary winding from switching from thyristor 19 to thyristor 2 does not change.

раз больше числа витков обмотки 15, т.е. сумма чисел витков всех первичных обмоток трансформатора 7 больше, чем трансформатора 8 в 1, 27 раз. Поэтому во столько же раз расчетная мощность первичных обмоток трансформатора 7 превышает расчетную мощность первичных обмоток трансформатора 8. Однако это не нарушает равенства углов проводимости во вторичной цепи, т.е. угол проводимости каждого диода и вторичной полуобмотки равен 180 эл. град.Thyristors and diodes form a rectified voltage at load 14 with a frequency of m = 12 in the following sequence: 22-12, 6-12, 19-13, 2-13, 20-12, 3-12, 23-13, 5-13, 18-12, 1-12, 21-13, 4-13. Thus, thyristor switching occurs at a frequency of 50 Hz, and diode switching, in accordance with a change in the direction of the magnetic flux relative to the secondary winding, occurs at a frequency of 150 Hz. Due to the half-wave rectification scheme on the secondary side of the converter, the increase and decrease of the secondary currents during the switching of the diodes occurs, despite the common secondary winding, in different circuits, one of which is in a previously de-energized state. The conduction angle of the primary winding 9 or 10 between its end and the intermediate terminal is 120 e. hail., and between the intermediate output and the beginning - 60 e. hail. The conduction angle of the primary winding 15 or 16 is 60 el. hail. On the other hand, the number of turns of the winding 9 is equal to the number of turns of the winding 10, and the number of turns of the winding 16 in

times the number of turns of the winding 15, i.e. the sum of the number of turns of all the primary windings of the transformer 7 is 1, 27 times greater than the transformer 8. Therefore, the design power of the primary windings of the transformer 7 is as many times the rated power of the primary windings of the transformer 8. However, this does not violate the equality of the conduction angles in the secondary circuit, i.e. the conduction angle of each diode and the secondary half-winding is 180 e. hail.

Instead of an additional three-phase transformer 17, a conventional four-wire network with a natural zero input terminal can be used. However, this is associated with the penetration into the supply network of higher harmonics that are multiples of three. The transformer 17 ensures the absence of these harmonics in the primary linear currents.

Similarly to the first variant of the proposed converter, the transformers of the second variant can be made on all types of the above magnetic cores, including two twisted tape magnetic cores with a longitudinal ring-shaped cross section, on two two-core magnetic cores with sectioned or non-partitioned primary and secondary windings, on two three-core flat magnetic circuits. In the case of two two-core magnetic cores with sectioned windings, it must be taken into account that each primary winding between its adjacent terminals, for example, between the intermediate and the extreme or between two extreme, should be divided into two sections and placed on different rods of the two-core magnetic core. Serial connection of it to the voltage of the supply network (as shown, for example, in Fig. 3, taking into account the correct connection of the beginnings and ends of the sections, ensures a consistent direction of the magnetic flux in the magnetic circuit. Secondary winding 11 must also be sectioned and connected as shown in Fig. 3). 3, i.e., paired in parallel.In this case, the series connection of the primary winding sections counteracts the current inequality in the parallel sections of the secondary semi-windings supplying each diode.

, отсчитываемом от ее конца. Магнитопроводы 7, 8, 24 размещены в полости общей вторичной обмотки 11, начало (конец) которой подключено к аноду диода 12 (13), а между общей точкой катодов диодов 12, 13 и средним выводом обмотки 11 подключена нагрузка 14. Концы обмоток 10; 9 и 16 подключены соответственно к входным выводам фаз А, С и В, а начала - к общим точкам пар тиристоров 1, 2; 3, 4 и 5, 6. Другие общие точки этих тиристоров к входным выводам фаз соответственно С, В и А. Преобразователь содержит дополнительный маломощный трехфазный трансформатор 17, обмотка которого соединена в звезду и подключена концами к фазным входным выводам А, В, С, а общей точкой начал образует искусственный нулевой входной вывод 0. Кроме того, преобразователь дополнительно содержит встречно-параллельно соединенные пары тиристоров соответственно 18, 19; 20, 21 и 22, 23, подключенные соответственно одной общей точкой к промежуточному выводу обмотки 10, 9 и 16, а другой - к нулевому входному выводу 0.The Converter in Fig.7 contains counter-parallel connected pairs of thyristors, respectively 1 and 2, 3 and 4, 5 and 6, 18 and 19, 20 and 21, 22 and 23, three transformers on twisted tape magnetic circuits 7, 8 and 24 with primary windings, respectively 9, 10 and 16, each of which contains an intermediate conclusion dividing its number of turns into parts in relation to

counted from its end. Magnetic cores 7, 8, 24 are placed in the cavity of the common secondary winding 11, the beginning (end) of which is connected to the anode of the diode 12 (13), and a load 14 is connected between the common point of the cathodes of the diodes 12, 13 and the middle terminal of the winding 11; The ends of the windings 10; 9 and 16 are connected respectively to the input terminals of phases A, C and B, and the beginning to the common points of the pairs of thyristors 1, 2; 3, 4 and 5, 6. Other common points of these thyristors to the input terminals of the phases, respectively, C, B and A. The converter contains an additional low-power three-phase transformer 17, the winding of which is connected to a star and connected by ends to the phase input terminals A, B, C, and the common point of origin forms an artificial zero input terminal 0. In addition, the converter additionally contains counter-parallel connected pairs of thyristors, respectively 18, 19; 20, 21 and 22, 23, respectively connected by one common point to the intermediate terminal of the winding 10, 9 and 16, and the other to the zero input terminal 0.

, размещенных на разных магнитопроводах с первичными обмотками соответственно 10 и 9, используется всего одна первичная обмотка 16 с промежуточным выводом, делящим ее число витков на части в отношении, равном

, но на дополнительном третьем магнитопроводе. Поэтому работа преобразователя по фиг.7 отличается от работы преобразователя по фиг.6 только тем, что вместо двух упомянутых первичных обмоток функционирует одна первичная обмотка на третьем магнитопроводе.The converter of FIG. 7 differs from the converter of FIG. 6 in that instead of the primary windings 15 and 16, with a reduced number of turns equal to 1 and

located on different magnetic cores with primary windings 10 and 9, respectively, only one primary winding 16 is used with an intermediate terminal dividing its number of turns into parts in a ratio equal to

, but on an additional third magnetic circuit. Therefore, the operation of the converter in Fig. 7 differs from the operation of the converter in Fig. 6 only in that instead of the two primary windings mentioned, one primary winding operates on the third magnetic circuit.

Thyristors and diodes form a rectified voltage at a load of 14 with a frequency of m = 12 in the following order: 22-12, 6-12, 19-13, 2-13, 20-12, 3-12, 23-13, 5-13, 18-12, 1-12, 21-13, 4-13. Similarly to the second option, thyristor switching occurs at a frequency of 50 Hz, and diode switching, in accordance with a change in the direction of the magnetic flux relative to the secondary winding, occurs at a frequency of 150 Hz. Due to the half-wave rectification scheme on the secondary side of the converter, the increase and decrease of the secondary currents during the switching of the diodes occurs, despite the common secondary winding, in different circuits, one of which is in a previously de-energized state. The conduction angle of each diode and secondary half-winding is 180 e. hail.

The conduction angle of each primary winding between its end (beginning) and intermediate terminal is 120 (60) e. hail. Therefore, taking into account the equality of their number of turns, they have equal design powers, i.e. transformers are identical.

The function of the auxiliary transformer 17 is similar to the second embodiment.

A special case of the Converter of Fig.7 is the Converter of Fig.8. The difference lies in the absence of intermediate terminals of the primary windings 9, 10, 16 and thyristors 18-23 connected to them, and also in the absence of the need for an additional transformer 17. The converter of Fig. 8 works with a frequency of m = 6, while the thyristors and diodes conduct currents with the following order: 6-12, 2-13, 3-12, 5-13, 1-12, 4-13. Thyristor switching occurs at a frequency of 50 Hz, and diode switching, in accordance with a change in the direction of the magnetic flux relative to the secondary winding, occurs at a frequency of 150 Hz. The conduction angle of each diode and secondary half-winding is 180 e. hail. The conduction angle of each primary winding is 120 e. hail.

Similarly to the first and second options of the proposed Converter, the transformers of the third option can be performed on the following types of magnetic cores: on three twisted tape magnetic cores with a longitudinal ring-shaped cross section and, for example, as shown in Fig. 5 with non-partitioned primary and secondary windings, but on three two-core magnetic cores, providing for the possibility of their mutual spatial shift by 120 el. hail. for uniform flux linkage with a common secondary winding. The actual design of the transformers, in contrast to the one shown in the drawings, should differ as close as possible relative to one another by the location of the magnetic cores, providing for minimizing the area of the cavity of the secondary winding or each of its sections.

Claims (16)

1. An AC to DC converter containing two single-phase transformers with primary and secondary windings, for example, sectioned, each primary connected by one output to the first common point of the main counter-parallel connected controlled valves, the second common point of which is connected to the phase input output, and free output - directly to the input output of the adjacent phase, additional counter-parallel connected controlled valves connected by the first common point to kr one terminal of one primary winding, two secondary windings, one pair of opposite terminals of which forms a common terminal, and the other is connected to the same electrode diodes connected by another pair of electrodes to the first output terminal, the second output terminal, characterized in that in any cavity formed by the secondary winding, one rod with the primary winding of each transformer is placed, the second common point of the additional controlled valves is connected to the corresponding terminal of the circuit, containing together with a pair of main ravlyaetsya valves another primary winding, and closes the series circuit, consisting of all controlled valves and one of the primary windings, and the total output of secondary winding connected to the second output terminal. 2. The Converter according to claim 1, characterized in that the rod of each transformer is wound from a steel strip and has a longitudinal cross-sectional shape, and the rods of both transformers are placed in the common cavity of the secondary windings. 3. The converter according to claim 1, characterized in that each transformer winding consists of two sections located on different rods of a 2-core magnetic circuit, and one rod with a primary winding section of each transformer is placed in the cavity of each section of the secondary winding. 4. The Converter according to claim 1, characterized in that the primary windings of each transformer are made on the middle rod of a 3-rod flat magnetic circuit, and the middle rods of both transformers are placed in the common cavity of the secondary windings. 5. The Converter according to claim 1, characterized in that the primary windings of each transformer are made on one rod of a 2-core magnetic circuit, and the indicated rods of both transformers are placed in the common cavity of the secondary windings. 6. An AC to DC converter containing two single-phase transformers with primary and secondary windings, for example, sectioned, each primary connected by the first extreme terminal to the phase input terminal, and the second extreme terminal and an intermediate terminal dividing its number of turns in relation

counted from the first extreme terminal to the first common points of the on-parallel-connected controlled valves, the second common points of which are connected respectively to the input terminal of the adjacent phase and the zero input terminal, the third primary winding connected similarly to the first two extreme terminals to the corresponding phase input terminals, two secondary windings, one pair of opposite terminals of which forms a common terminal, and the other is connected to the same electrode diodes connected by another pair of electrodes to the first output terminal, second output terminal, additional counter-parallel-connected controlled valves, characterized in that in any cavity formed by the secondary winding, there is one rod with the primary winding of each transformer, the common output of the secondary windings is connected to the second output terminal, the third primary winding made on one transformer, and on the other an additional primary winding, with the number of turns equal to the number of turns of the main between the first extreme and intermediate terminals, connected by one output to the first extreme terminal of the third primary winding, and the other to the first common point of the mentioned additional valves, the second common point of which is connected to the zero input terminal. 7. The Converter according to claim 6, characterized in that the core of each transformer is wound from a steel strip and has a ring-shaped shape in longitudinal section, and the rods of both transformers are placed in the common cavity of the secondary windings. 8. The Converter according to claim 6, characterized in that each transformer winding between its adjacent terminals consists of two sections located on different rods of a 2-core magnetic circuit, and one rod with a primary winding section of each transformer is placed in the cavity of each section of the secondary winding. 9. The converter according to claim 6, characterized in that the windings of each transformer are made on the middle rod of a 3-rod flat magnetic circuit, and the middle rods of both transformers are placed in the common cavity of the secondary windings. 10. The Converter according to claim 6, characterized in that the windings of each transformer are made on one rod of a 2-core magnetic circuit, and in the common cavity of the secondary windings the indicated rods of both transformers are placed, 11. The Converter according to claim 6, characterized in that it contains an additional transformer, the primary winding of which is connected to a "star" and connected by one of the conclusions and the common point of the other conclusions, respectively, to the phase and zero input terminals. 12. An AC to DC converter containing three single-phase transformers, with primary windings, each connected by one output to the first common point of the on-parallel-connected controlled valves, the second common point of which is connected to the phase input output, and the free output directly to the input output the corresponding adjacent phase, two secondary windings, one pair of opposite terminals of which forms a common terminal, and the other is connected to the same electrodes of the diodes connected to other goy pair of electrodes to a first output terminal, the second output terminal, characterized in that the secondary windings form a common cavity in which is placed a rod with a primary winding of each transformer, and the total output of secondary winding connected to the second output terminal. 13. The Converter according to item 12, characterized in that the primary winding of each transformer contains an intermediate output, dividing it into parts in relation

most of which are counted from the aforementioned free input terminal, and connected to one terminal of the corresponding additionally introduced pair of counter-parallel controllable gates, the other terminal of which is connected to the zero input terminal. 14. The Converter according to item 12 or 13, characterized in that the rod of each transformer is wound from a steel strip and has a longitudinal section in the form of a ring, and the rods of three transformers are placed in the common cavity of the secondary windings. 15. The Converter according to item 12 or 13, characterized in that the windings of each transformer are made on one rod of a 2-core magnetic circuit, and the said rods of three transformers are placed with the possibility of mutual spatial shift in the common cavity of the secondary windings. 16. The Converter according to item 13, characterized in that it contains an additional transformer, the primary winding of which is connected to a "star" and connected by one of the conclusions and the common point of the other conclusions, respectively, to the phase and zero input terminals.

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