SU942224A1

SU942224A1 - Three-phase static converter

Info

Publication number: SU942224A1
Application number: SU792831882A
Authority: SU
Inventors: Вадим Андреевич Иванченко; Семен Соломонович Клямкин
Original assignee: Научно-Исследовательский Институт Постоянного Тока
Priority date: 1979-10-25
Filing date: 1979-10-25
Publication date: 1982-07-07

Description

Изобретение относится к преобразовательной технике и предназначено для использования в электротехнических и радиотехнических установках.The invention relates to a conversion technique and is intended for use in electrical and radio installations.

Для преобразования напряжения из постоянного в трехфазное перемен- ⁵ное или из трехфазного переменного в постоянное широко применяют трехфазную мостовую схему, содержащую в каждом из шести плеч ключевые эле- _J0менты, неуправляемые или управляемые частично или полностью (диоды, тиристоры, транзисторы и лампы и др) [1].To convert DC voltage from a three-phase alternating Noe ⁵ or from the three phase AC to DC widely used a three-phase bridge circuit comprising in each of the six arms key element _J0 cops, unguided or guided partly or completely (diodes, thyristors, transistors, lamps and other) [1].

Типичной аварией трехфазного мо- _t5стового преобразователя является короткое замыкание по одному:иэ плеч моста вследствие потери запирающих свойств одним из ключей (электрический пробой, неисправность системы 20 управления и др.), сопровождающееся повышенным аварийным током. Скорость нарастания и амплитуду тока короткого' замыкания обычно ограничивают реактором, включенным в цепь питания или в плечи моста, ухудшающим работу преобразователя в нормальных режимах. Реактор снижает предельную частоту преобразователя, приводит к накапливанию энергии и перенапряжениям на элементах схемы, к дополнительным потерям энергии и к снижению КПД преобразователя.A typical accident phase MO _t5 STOV inverter is short-circuited by one: IE bridge arms due to the loss of the locking properties of one of the keys (electrical breakdown, failure of a control system 20, and others.), Accompanied by an increased fault current. The slew rate and the amplitude of the short-circuit current are usually limited by a reactor connected to the power supply circuit or to the shoulders of the bridge, impairing the operation of the converter in normal conditions. The reactor reduces the limit frequency of the converter, leads to the accumulation of energy and overvoltage on the circuit elements, to additional energy losses and to reduce the efficiency of the converter.

Ограничение токов короткого замыкания в преобразователях с помощью плавких вставок £2j приводит к необходимости их замены после срабатывания, кроме того, они имеют низкую' чувствительность.The limitation of short-circuit currents in the converters using fuse-links £ 2j leads to the need to replace them after operation, in addition, they have a low sensitivity.

Наиболее близким к предлагаемому является статический мостовой преобразователь , у которого последовательно с каждым вентилем включен ' дроссель, причем обмотки дросселей, включенные в противолежащие плечи ' моста, размещены на общем магнитопроводе и включены встречно одна относительно Другой Сз1·’ ‘ !The closest to the proposed one is a static bridge converter, in which a throttle is connected in series with each valve, and the windings of the throttles included in the opposite shoulders of the bridge are placed on the common magnetic circuit and are turned on one opposite to the other Sz1 · ’‘!

Недостатком этого устройства при трехфа?ной мостовой схеме преобра- . эователя является то, что указанные дроссели должны иметь малую индуктивность, и, соответственно., мало ограничивают аварийные токи, что приводит к снижению надежности схемы. Большая индуктивность недопустима из-за режимов горения по трем вентилям, так как при этом повышается время коммутации тока, в прилежащих плечах снижается выпрямленное напряжение, cosЧ* и другие основные показатели нормального режима.The disadvantage of this device with a three-bridge bridge circuit is converted. It is necessary that these chokes should have a low inductance, and, accordingly, they will limit emergency currents a little, which leads to a decrease in the reliability of the circuit. A large inductance is unacceptable due to the combustion regimes of the three valves, since this increases the switching time of the current, in the adjacent shoulders the rectified voltage, cos * and other basic indicators of the normal mode decrease.

’Цель изобретения - повышение надежности статического преобразователя.’The purpose of the invention is to increase the reliability of the static Converter.

Поставленная цель достигается тем, что в трехфазном статическом преобразователе, содержащем вентильный мост с попарно магнитосвязанными обмоткёми дросселей, включенными встреч-* * но по отношению друг к другу, последовательно с каждым вентилем включены две параллельно соединенные обмот-] ки, причем каждые две обмотки дроссе-;²⁵лей одной фазы, включенные в анодную группу моста, магнитосвязаны с обмотками дросселей двух других фаз, включенными в катодную группу моста.This goal is achieved by the fact that in a three-phase static converter containing a valve bridge with magnetically coupled windings of the chokes, turned on- * * but with respect to each other, two parallel connected windings are connected in series with each valve, and every two windings of the dross -; ²⁵ lei of one phase included in the anode group of the bridge are magnetically connected to the windings of the chokes of the other two phases included in the cathode group of the bridge.

На чертеже представлена сх^ма преобразователя. .The drawing shows the converter circuit. .

Схема включает источник 1 питания (или нагрузку), ключевые элементы (вентили) 2-7, нагрузку (или источник питания) 8, дроссели 9“14, сгла, живакхций дроссель 15.The circuit includes a power supply 1 (or load), key elements (valves) 2-7, a load (or power supply) 8, inductors 9 “14, a diode, live reactors inductor 15.

Пары магнитосвяз^нных дросселей обозначены одним номером.Pairs of magnetically coupled chokes are indicated by one number.

нормальных режимах ток протелибо по двум вентилям (напри2 и 6), либо по трем (напри2, 6 и 7). В обоих случаях дросне оказывают сопротивления протак как их . При вклюUnder normal conditions, the current flowed through two valves (for example 2 and 6), or in three (for example 2, 6 and 7). In both cases, thrush resist a protak like them. When I turn on

IS . 30 *IS. thirty *

В кает мер, мер, сели теканию токов в схеме, обмотки включены встречно ценных вентилях 2 и 6 ток протекаетIn the case of measures, measures, the currents flow in the circuit, the windings are turned on counter-valuable valves 2 and 6, the current flows

942224 4 только по обмоткам дросселей 9. При переходе тока с вентиля 6 на вентиль 7 он одновременно под действием коммутирующей ЭДС беспрепятственно переходит из обмоток дросселей 9 в обмотки дросселей 10. При коротком замыкании по одному из плеч нарастание аварийного тока ограничивается ве'лиминой полного индуктивного сопро- тивления одного дросселя (четыре не имеющих общего магнитного, потока дросселя включены попарно параллельно-последовательно).942224 4 only along the windings of the chokes 9. When the current passes from valve 6 to valve 7, it simultaneously under the influence of a switching EMF freely passes from the windings of the chokes 9 to the windings of the chokes 10. In the event of a short circuit along one of the arms, the increase in the emergency current is limited by the maximum inductive the resistance of one inductor (four not having a common magnetic flux of the inductor are connected in pairs in parallel-series).

В случае короткого замыкания по двум или трем плечам преобразователя имеющиеся дроссели обеспечивают равномерное деление аварийного тока между плечами.In the event of a short circuit on two or three arms of the converter, the existing chokes provide a uniform division of the emergency current between the arms.

Claims

The invention relates to a conversion technique and is intended for use in electrical and radio engineering installations. To convert voltage from a constant to a three-phase AC or from a three-phase AC to a constant, a three-phase bridge circuit containing key elements uncontrollable is widely used. or controlled partially or completely (diodes, thyristors, transistors and lamps, etc.) 1. A typical accident of a three-phase bridge converter is a short 3 junction across dnomuie bridge arms due to the loss of the locking properties of one of the keys (electric breakdown neisprav.nost siste.my controlling et al.) up, followed by high fault current. The slew rate and amplitude of the short-circuit current are usually limited to a reactor connected to the power supply or to the shoulders of the bridge, which impair the operation of the converter in normal conditions. The reactor reduces the limiting frequency of the converter, leads to energy accumulation and overvoltages on the circuit elements, to additional energy losses and to a decrease in the efficiency of the converter. The limitation of short-scale currents in converters using fusible plugs, 2} makes it necessary to replace them after they are triggered, and they also have sensitivity. Closest to the offer is a static bridge converter, in which it is consistent. with each valve, a choke is turned on, and the windings of chokes, included in the opposite bridge pits, are placed on a common magnetic conductor and are connected opposite one with respect to Other Cz1. The disadvantage of this device when a three-phase bridge circuit is transformed. The evater is that the chokes must have a low inductance, and accordingly, the emergency currents are limited to a small extent, which leads to a decrease in the reliability of the circuit. Large inductance is unacceptable because of the burning modes in three valves, since this increases the switching time of the current, the rectified voltage, cos H and other basic indicators of the normal mode decrease in the adjacent arms. The purpose of the invention is to increase the reliability of the static converter. This goal is achieved by the fact that in a three-phase static converter containing a valve bridge with pair-wise magneto-coupled windings of chokes, which are connected in relation to each other, two parallel-connected windings are connected to each valve in series, included in the anode group of the bridge, are magnetically connected with the windings of the chokes of the other two phases included in the cathode group of the bridge. The drawing shows the cxieMa converter. . The circuit includes power supply 1. (or load), key elements (gates) 2-7, load (or power supply) 8, chokes 9-1, burned, living choke 15. Pairs of magnetically coupled chokes are denoted by one number. In normal modes, the current flows through either two valves (for example, 2 and 6), or three (for example, 2, 6 and 7). In both cases the droplets do not resist the flow of currents in the circuit, since their windings are connected in opposite directions. When valves 2 and 6 are turned on, the current flows only through the windings of the chokes 9. When the current passes from valve 6 to valve 7, it simultaneously under the action of the switching electromotive force, unhindered from the windings of the chokes 9 to the windings of the chokes 10 from the shoulders, the rise of the emergency current is limited by the full inductive resistance of one drossel (four that do not have a common magnetic, the throttle fluxes are connected in pairs in parallel-series). In the event of a short circuit across the two or three transducer arms, the available chokes provide a uniform division of the fault current between the arms. A three-phase static converter comprising a valve bridge with pairwise magnetically coupled windings of chokes connected oppositely to each other and in series with each bridge valve, differing in that, in order to increase reliability, two parallel-connected windings are connected with each valve Each of the two windings of the chokes of one phase, included in the anode group of the bridge, is magnetically connected with the windings of the chokes of the other two phases, included in the cathode group of the bridge. Sources of information taken into account in the examination 1. Autonomous inverters. Ed. GV Chaly. Stinitsa, 197, with. 172.

2.Rivkin G.A. High power conversion plants. SEI, 1959, p. 225.

3. Authors certificate of the USSR (f 650189, class H 02 M 7/515, 1977.