SU824388A2

SU824388A2 - Three-phase inverter

Info

Publication number: SU824388A2
Application number: SU792792648A
Authority: SU
Inventors: Виктор Романович Бирюков
Original assignee: Предприятие П/Я В-2431
Priority date: 1979-07-09
Filing date: 1979-07-09
Publication date: 1981-04-23

Description

(54) ТРЕХФАЗНЫЙ ИНВЕРТОР(54) THREE-PHASE INVERTER

1one

Изобретение относитс к электротехнике и может быть использовано в системах электропитани и электропривода дл преобразовани посто нного напр жени в трехфазное переменное напр жение посредством инверторов .The invention relates to electrical engineering and can be used in power supply and electric drive systems for converting a DC voltage to a three-phase AC voltage by means of inverters.

По основному авт. св. № 652670 известен трехфазный инвертор, который содержит трехфазный мост управл емых ключей, подключенный к входным выводам, дополнйтель ную двухтактную чейку, выход которой подключен между выводом дл подклк)чени средней точки источника и выводом дл подключени нулевой точки трехфазной нагрузки , и блок управлени , причем двухтактова чейка имеет дополнительный выход, кото-, рый подключен через дополнительные управл емые ключи переменного тока к выходу трехфазного моста и к выводу дл подключени нулевой точки трехфазной нагрузки 1.According to the main author. St. No. 652670 is a three-phase inverter that contains a three-phase controlled key bridge connected to the input terminals, an additional push-pull cell whose output is connected between the output for connecting the center point of the source and the output for connecting the zero point of the three-phase load, and a control unit the two-stroke cell has an additional output that is connected via additional controlled AC switches to the output of the three-phase bridge and to the output for connecting the zero point of the three-phase load one.

Цель изобретени - упрощение блока управлени инвертора.The purpose of the invention is to simplify the inverter control unit.

Поставленна цель достигаетс тем, что три транзистора трехфазного моста выполнены р-п-р типа, а три других транзистора - п-р-п типа, а базы транзисторов одинакового типа проводимости через обмотки трансформатора блока управлени соединены с .первым выводом общего базового резистора, второй вывод которого подключен к эмиттерам этих транзисторов.,The goal is achieved by the fact that three transistors of a three-phase bridge are made of pnp type, and three other transistors are pnp type, and the bases of transistors of the same conductivity type are connected to the first terminal of a common base resistor, through transformer windings the second output of which is connected to the emitters of these transistors.,

На фиг. 1 представлена принципиальна электрическа схема предлагаемого трехфазного инвертора; на фиг. 2 - эпюры напр жений , по сн ющие принцип действи .FIG. 1 shows the basic electrical circuit of the proposed three-phase inverter; in fig. 2 - stress diagrams, explaining the principle of operation.

Инвертор содержит трехфазный транзисторный мост на транзисторах , источник 7 питани со средней точкой, выходные обмотки 8--13 трансформаторов управлени , резисторы 14 и 15, двухтактную чейку 16 и ключи 17 переменного тока.The inverter contains a three-phase transistor bridge on transistors, a mid-point power supply 7, output windings 8-13 of control transformers, resistors 14 and 15, a push-pull cell 16, and AC switches 17.

Трехфазный мост на транзисторах 1-6 подключен к источнику 7 питани , выходные обмотки трансформаторов управлени подключены через резисторы 14 и 15 к управл ющим входам транзисторов 1-6, один из входов двухтактной чейки 16 включен между средней точкой источника питани и нулевой точкой трехфазной нагрузки, а другой - параллельно на.грузке через ключи 17 переменного тока.A three-phase bridge on transistors 1-6 is connected to the power supply 7, the output windings of the control transformers are connected through resistors 14 and 15 to the control inputs of transistors 1-6, one of the inputs of the push-pull cell 16 is connected between the midpoint of the power supply and the zero point of the three-phase load, and the other in parallel on the load through the keys 17 AC.

Claims

The device works as follows. Phase A voltage (Fig. 2a) is generated with transistors 1 and 4 and a push-pull cell 16. The first stage is generated with keys 17, connecting the output of cell 16 in parallel with the load. The second and third stages are formed with the help of transistors 1 and 4, connecting the power supply voltage over the interval 120 (Fig. 2a, dashed line), which is added to the voltage of the push-pull cell (output connected between the midpoint of the power source and the zero point of the three-phase load). Similarly, the voltages of other phases are formed. To control transistors 1-6, opening pulses are needed at 120 ° intervals and locking pulses at 240 ° intervals. Usually, additional elements are required to obtain a blocking pulse, which complicates the inverter circuit. In order to simplify, the three-phase bridge is made on ppp and ppp transistors. In this case, it is possible to close phase A transistor 1 in section tj-U (Fig. 2b) with opening signals of transistors 2 and 3 in sections and tj -ti, phases B and C Indeed, if the transistor 2 is open at the U-tj portion of the resistor 14, a signal is released that through the winding 8 is applied Fmg. It rises to the input of transistor 1 in the blocking direction. Similarly, all other transistors 2-6 are locked. Thus, the use of transistors with different types of conductivity allows us to simplify the inverter circuit in part of the control circuit. In addition, the number of resistors in the control circuit of transistors 1-6 is reduced from two to two. The invention is a three-phase inverter according to the author. St. No. 652670 characterized in that, in order to simplify, the three-phase bridge is made of three type pnp transistors, the emitters of which are connected to the positive input terminal of the inverter, and three pnp type transistors, the emitters of which are connected to the negative input terminal, and the bases of transistors of the same conductivity type are connected through the transformer windings of the control unit to the first terminal of the common base resistor, the second terminal of which is connected to the emitters of these transistors. Sources of information taken into account during the examination 1. USSR Author's Certificate No. 652673, cl. H 02 M 7/515, 1976.

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