RU2340072C1 - Ac-to-dc voltage transducer - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: AC-to-DC voltage transducer provides AC-to-DC voltage transformation for power supply of high-demanding consumers with exclusive standards for rectified voltage quality. It contains two three-phase transformers (1) and (2), forming two phase-shifted relatively to each other at 30 electrical degrees six-phase voltage system expressed with phase leads a, z, b, x, u of six-phase star and with leads a', z,' b', x', c', u' of the second six-phase star, as well as twenty four isolators (3...26) used to form two six-isolator stars, anode of isolators (3), (7), (12), (15), (20), (23) and cathodic of isolators (5), (6), (9), (14), (17), (22) and twelve-isolator ring (isolators (4), (8), (10), (11), (13), (16), (18), (19), (21), (24), (25), (26) so that power electrodes of similar isolators. And each phase of secondary windings of transformer (1) (2) is connected to integrated anodes (cathodes) of two isolators through which it is connected to two phases of secondary windings of transformer (2) (1), having relative phase shift

electrical degrees relative to this phase. Common points (27) and (28) of isolator connection of anode and cathodic six-isolator stars respectively form output leads of transducer with connected loading (29). Each connection point of twelve-isolator ring isolator electrodes has connected electrode of the other name and attached to one isolator of six-isolator stars. Thus numbers of secondary phase winding turns of both stars (back stars), comprising six-phase stars are equal, while ratio of numbers of stars secondary phase windings turns (back stars) to numbers of secondary phase winding turns of back stars (stars) is

.

EFFECT: twenty-four-fold ripple frequency of rectified voltage.

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Description

The invention relates to electrical engineering and power converting equipment and can be used as an AC to DC converter for supplying consumers with increased demands on the quality of the rectified voltage.

A known converter of alternating voltage to DC, providing m-fold frequency of the ripple of the rectified voltage (considered m = 24), containing 12 sources of arbitrary EMF and 24 valves connected to two series-connected six-cell valve bridges [A.S. USSR No. 917280, MKI N02M 7/10, publ. 03/30/1982].

The disadvantage of this converter is the large number of transformers used - twelve single-phase or four three-phase, and relatively large power losses in the valves, sequentially streamlined by the load current.

, считается от одноименного зажима каждой обмотки, причем первичные обмотки одного трансформатора соединены в звезду, а второго в треугольник, а выходы всех выпрямителей включены параллельно.Also known is an AC to DC converter, providing a twenty-fourfold frequency of the ripple of the rectified voltage [Pat. No. 2219647 of the Russian Federation, MKI N02M 7/08, publ. December 20, 2003], containing two three-phase transformers, the secondary phase windings of each transformer are connected in a triangle, and each phase secondary winding is equipped with two internal taps that are connected to the AC diagonals of two bridge rectifiers connected in parallel in the input, while the indicated taps from the phase windings are made from parts in the ratio

, is counted from the same clamp of each winding, with the primary windings of one transformer connected to a star, and the second to a triangle, and the outputs of all rectifiers are connected in parallel.

The disadvantages of this converter are the large weight and size indicators and the use of secondary windings in transformers, parts of which have three values of coil numbers, which at small numbers of turns limits the ability to provide a calculated ratio of the number of turns, thereby reducing the efficiency of electric energy conversion.

эл. град. относительно данной фазы, при этом общие точки соединения вторичных обмоток в каждом трансформаторе образуют два выходных вывода преобразователя.Closest to the invention adopted for the prototype is an AC to DC converter (AS USSR No. 803089, MKI N02M 7/06, publ. 02/07/1981), containing two three-phase transformers, the primary winding of one transformer is made according to the star scheme , the second according to the scheme is a triangle, and the secondary windings in each transformer are made according to the star and reverse star circuits connected by zero points to a six-phase star, and twelve valves forming a twelve-vent ring circuit connected in series ak that have the same name are combined pairwise power electrodes, each phase of the secondary windings of the first transformer is connected to the combined power of the same name electrodes two gates through which it is connected with two phases of the second transformer secondary winding having a relative phase shift

email hail. relative to this phase, while the common connection points of the secondary windings in each transformer form two output terminals of the converter.

The specified Converter provides only twelve times the ripple frequency of the rectified voltage.

The objective of the invention is the creation of an AC to DC converter, providing twenty-four times the ripple frequency of the rectified voltage.

эл. гр. относительно данной фазы, при этом он снабжен двенадцатью дополнительными вентилями, соединенными в две шестивентильных звезды, анодную и катодную, общие точки соединения вентилей которых образуют выходные выводы преобразователя, причем к каждой точке соединения одноименных электродов вентилей двенадцативентильного кольца присоединен силовой электрод с другим наименованием, принадлежащий одному из вентилей шестивентильных звезд, при этом числа витков вторичных фазных обмоток обеих звезд (обратных звезд) равны, а отношение чисел витков вторичных фазных обмоток звезд (обратных звезд) к числам витков вторичных фазных обмоток обратных звезд (звезд) составляет

.This task is achieved by the fact that the AC to DC converter contains two three-phase transformers, the primary winding of one transformer is made according to the star scheme, the second according to the triangle scheme, and the secondary windings in each transformer are made according to the star and reverse star circuits connected by zero points to a six-phase star , and twelve gates forming a twelve-valve ring circuit, connected in series so that they have the same name electrodes in pairs, etc. than the secondary windings of each phase of the transformer is connected to the combined power of the same name electrodes two gates through which it is connected to the secondary windings of the two phases other transformer having a relative phase shift

email column relative to this phase, while it is equipped with twelve additional valves connected to two six-valve stars, anode and cathode, common points of connection of the valves of which form the output terminals of the converter, and a power electrode of a different name is attached to each connection point of the same electrode of the valves of the twelve-valve ring one of the valves of hexavalent stars, while the number of turns of the secondary phase windings of both stars (reverse stars) are equal, and the ratio of the numbers of turns of the secondary phase windings of stars (reverse stars) to the number of turns of the secondary phase windings of reverse stars (stars) is

.

Figure 1 shows a circuit diagram of the proposed Converter; figure 2 - vector voltage diagrams presented in the form of amplitude-phase portraits of voltages of the secondary phase windings; figure 3 - detailed vector diagrams explaining the principle of formation of the vectors of the resulting stresses; figure 4 is a diagram of the operation of the windings and valves of the Converter, showing the circuit flow of the load current in each of the twenty-four phases of the conversion process.

эл. гр. относительно данной фазы. Общие точки 27 и 28 соединения вентилей соответственно анодной и катодной шестивентильных звезд образуют выходные выводы преобразователя, к которым подключена нагрузка 29. К каждой точке соединения одноименных электродов вентилей двенадцативентильного кольца присоединен электрод с другим наименованием, принадлежащий одному из вентилей шестивентильных звезд, при этом числа витков вторичных фазных обмоток обеих звезд (обратных звезд), составляющих шестифазные звезды, равны, а отношение чисел витков вторичных фазных обмоток звезд (обратных звезд) к числам витков вторичных фазных обмоток обратных звезд (звезд) составляет

.The AC to DC Converter (Figure 1) contains two three-phase transformers 1 and 2, forming two phase-shifted by 30 el. hail. six-phase EMF systems relative to each other, represented by the phase leads a, z, b, x, s, y of one six-phase star and the leads a ', z' in ', x', c ', y' - the second six-phase star, as well as twenty four valves 3 ... 26, of which two six-valve stars are formed, the anode of valves 3, 7, 12, 15, 20, 23 and the cathode of valves 5, 6, 9, 14, 17, 22 and the twelve-valve ring (valves 4 , 8, 10, 11, 13, 16, 18, 19, 21, 24, 25, 26) so that the same power electrodes of the valves are combined in pairs, while each phase of the secondary windings of the transformer 1 (2) is connected to the combined anodes (cathodes) of the two valves, via which it is connected with two phases of the secondary windings of the transformer 2 (1) having a relative phase shift

email column relative to this phase. Common points 27 and 28 of the connection of the valves of the anode and cathode six-valve stars, respectively, form the output terminals of the converter, to which the load 29 is connected. An electrode with a different name, connected to one of the valves of the six-valve stars, is connected to each connection point of the same electrode valves of the twelve-valve rings, with the number of turns the secondary phase windings of both stars (reverse stars) constituting six-phase stars are equal, and the ratio of the numbers of turns of the secondary phase windings of stars (reverse x star) to the numbers of turns of the secondary phase windings inverse star (star) is

.

The principle of operation of the device (Figure 1) is illustrated by vector diagrams of voltage sources EMF, presented in the form of amplitude-phase portraits of the voltage of the secondary windings (Figure 2) and detailed vector diagrams explaining the principle of formation of the vectors of the resulting voltages (Figure 3), as well as the diagram the work of the windings and valves of the Converter, revealing the flow of the load current in each of the twenty-four phases of the conversion process (Figure 4).

. При таком соотношении обеспечивается динамичное формирование результирующих напряжений, модули векторов которых равны и сдвинуты друг относительно друга на фазовой плоскости на 15 эл. град. Условно зафиксировав векторную диаграмму напряжений одной системы и перемещая вокруг нее векторную диаграмму напряжений другой системы, за период сетевого напряжения получим 24 вектора результирующих напряжений (Фиг.3). В каждом положении систем на фазовой плоскости определяются элементы вентильных связей, время работы вентилей и вторичных обмоток. Для иллюстративности на Фиг.3 приведены два положения систем на фазовой плоскости, при которых формируются векторы результирующих напряжений S1...S3, S23, S24. Весь цикл работы преобразователя при идеальной коммутации представлен токопроводящими цепями на Фиг.4.Vector diagrams (Figure 2) show the amplitude-phase characteristics of each of the six-phase EMF systems used. The ratio of the number of turns of the phase windings of the star and the reverse star in each source of EMF is

. With this ratio, the dynamic formation of the resulting stresses is provided, the vector modules of which are equal and shifted relative to each other on the phase plane by 15 el. hail. Conventionally fixing the vector diagram of the voltages of one system and moving around it the vector diagram of the voltages of another system, for the period of the mains voltage we get 24 vectors of the resulting voltages (Figure 3). In each position of the systems on the phase plane, the elements of valve connections, the operating time of the valves and secondary windings are determined. For illustrative purposes, Fig. 3 shows two positions of systems in the phase plane at which the resulting voltage vectors S1 ... S3, S23, S24 are formed. The entire cycle of the Converter with perfect switching is represented by conductive circuits in Figure 4.

The analysis of vector diagrams showed that the windings of three-phase stars making up six-phase stars are in a conducting state of 150 el. hail., and windings of reverse stars - 90 el. hail. Valves 3, 12, 20; 6, 14, 22 of the anodic and cathodic valve stars pass a current of 45 el. hail., and valves 7, 15, 23; 5, 9, 17 - 75 email. hail. The conduction angle of the valves 4, 13, 21 of the ring is 45 el. hail., valves 8, 11, 16, 19, 24, 26 - 30 email. hail., and valves 10, 18, 25 - 15 el. hail.

The total power of the secondary windings of the transformers of the proposed device is equal to 1.274 · P _d , while the total power of the secondary windings of the transformers of the prototype is 1.388 · P _d . The transformers of the proposed Converter have an estimated typical power S _T = 1,185 · R _d . Given the need to increase the typical power of the transformer 1 (Figure 1) due to the action of the magnetizing forces created by the 3rd and multiple harmonics of the currents of the secondary windings, the overall dimensions of the transformers of the proposed device are slightly different from the transformers of the prototype.

The proposed converter, assembled according to the twenty-four pulse rectification scheme, provides better quality of the rectified voltage and the consumed alternating currents than the prototype.

In addition, the use of secondary windings in transformers of a converter with two closer values of the number of turns (in relative units of 1.0 and 0.8587) compared with the ratios of the number of turns of the secondary windings of transformers of other 24-pulse converters provides better equality of electromagnetic conditions for the windings when placed in the magnetic circuit window. This broadens the possibilities of choosing circuit solutions for integer manufacturing of secondary windings, which is essential when creating powerful converters, as well as with a relatively low level of rectified voltage, when it is difficult to ensure the value of the structural asymmetry of the secondary winding voltages within specified limits.

Three valve arms are connected in series in the load current flow circuit, which may be the optimal solution for a certain part of consumers.

Thus, the proposed Converter AC to DC has, compared with the prototype, twenty-four times the frequency of the ripple of the rectified voltage.

Claims (1)

An AC to DC converter containing two three-phase transformers, the primary winding of one transformer is made according to the star scheme, the second according to the triangle scheme, and the secondary windings in each transformer are made according to the star and reverse star schemes connected by zero points to a six-phase star, and twelve valves, forming a twelve-vent ring circuit connected in series so that they have the same name electrodes in pairs, with each phase of the secondary circuits a transformer connected to the combined power of the same name electrodes two gates through which it is connected to the secondary windings of the two phases other transformer having a relative phase shift

electrical degrees relative to this phase, characterized in that it is equipped with twelve additional valves connected to two six-valve stars, anode and cathode, the common connection points of the valves of which form the output terminals of the converter, and a power electrode is connected to each connection point of the same electrode of the valves of the twelve-valve ring another name belonging to one of the valves of six-star stars, while the number of turns of the secondary windings made according to the star circuit yes, equal to each other, the number of turns of the secondary windings made according to the reverse star scheme, are also equal to each other, the ratio of the numbers of turns of the secondary windings made according to the reverse star scheme to the numbers of turns of the secondary windings made according to the star scheme, or the numbers of turns of the secondary windings made according to the star pattern to the numbers of turns of the secondary windings made according to the reverse star pattern is

.

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