SU991565A1

SU991565A1 - Series inverter

Info

Publication number: SU991565A1
Application number: SU813311052A
Authority: SU
Inventors: Александр Васильевич Иванов; Владимир Михайлович Марон; Петр Семенович Ройзман; Альберт Хубутдинович Узянбаев; Рифхат Гадылевич Юнусов
Original assignee: Уфимский авиационный институт им.С.Орджоникидзе
Priority date: 1981-07-03
Filing date: 1981-07-03
Publication date: 1983-01-23

Description

Изобретение относитс к преобразовательной технике и может быть использовано в высокочастотных регулируемых электротерг шческих установках .The invention relates to converter equipment and can be used in high frequency adjustable electrothermal installations.

Известны инверторы, содержащие последовательные колебательный цепи, встречно-параллельные пары вентилей и входные фильтры 1.Known inverters containing serial oscillatory circuit, anti-parallel pairs of gates and input filters 1.

Недостатком этих инверторов вл - , етс ограниченный снизу диапазон регулировани мощности.The disadvantage of these inverters is the limited range of power control from below.

Наиболее близким к изобретению вл етс инвертор, содержащий последовательные LC-цепи, св занные с выходными зажимами, встречно-параллельные пары вентилей, подключенные к входным,выводам через фильтровый дроссель, и дроссель насыщени 2.Closest to the invention is an inverter comprising serial LC circuits connected to output terminals, anti-parallel valve pairs connected to input terminals through a filter choke, and a saturation choke 2.

Недостатками инвертора вл ютс сложность и большие габариты, обусловленные наличием дроссел насыщени , и высокий уровень искажений в сети при работе инвертора в промежуточном между режимами малой и максимальной входной мощности. Последнее обусловлено тем, что амплитуда переменной составл ющей входного тока при насыщенном дросселе, т.е. во всех режимах, кроме режима малой мощности.The disadvantages of the inverter are the complexity and large size, due to the presence of saturation throttles, and the high level of distortion in the network when the inverter operates in the intermediate mode between low and maximum input power. The latter is due to the fact that the amplitude of the variable component of the input current with a saturated choke, i.e. in all modes except low power mode.

не зависит от величины входной мощности и имеет величинуdoes not depend on the value of input power and has a value

С-% где и - напр жени источника питани ;C-% where and are the voltage of the power source;

L - динамическа индуктивность дроссел фильтра;L is the dynamic inductance of the filter drossel;

f - частота выходного тока;f is the frequency of the output current;

q - скважность выходного тока. q is the duty cycle of the output current.

10 Причем динамическа индуктивность линейного дроссел не зависит от уровн посто нной составл ющей входного тока. Индуктивность линейного дроссел фильтра ограничиваетс его 10 Moreover, the dynamic inductance of a linear droplet does not depend on the level of the constant component of the input current. The inductance of the linear throttle filter is limited by its

15 габаритами и велччиной тока насыщени , т.е. величиной входного тока в режиме максимальной мощности. При снижении мощности от максимальной величины посто нна составл юща 15 dimensions and high saturation current, i.e. the value of the input current in the maximum power mode. When the power decreases from the maximum value, the constant component is

20 входного тока снижаетс , что приводит к увеличению отношени lyy, / . Вместе с тем дроссель не используетс полностью, поскольку величина тока , протекающего в нем, значительно The input current 20 decreases, resulting in an increase in the ratio lyy, /. However, the choke is not fully utilized, since the amount of current flowing through it is significantly

25 ниже номинального уровн , что составл ет резерв дл увеличени индуктивности .25 below the nominal level, which is a reserve for increasing the inductance.

Целью изобретени вл етс упрощение и снижение искажений в питаю- The aim of the invention is to simplify and reduce the distortions in the power supply.

Claims

30th network. The goal is achieved by the fact that in an inverter containing a counter-parallel valve pair connected to the input pins via a filter choke and a serial LC chain connected to the output pins, the filter choke is nonlinear with a maximum current characteristic decreasing in the operating input current range negative slope at a current value corresponding to the mode of low input power. The use of droplets of the filter with a falling Henry-ampere characteristic makes it possible to reduce the variable component of the input current while adjusting the power from the maximum value downwards without increasing the overall dimensions relative to the dimensions of the villages of the filter. An increase in the inductance of the filter droplets with a decrease in the current level, and with a maximum negative slope at low currents, also makes it possible to reject the droplets from the saturation that adds an additional inductance only in the low massed mode. To obtain a constant fyvi / Jf ratio as can be seen from (1), it is necessary to implement the Henry-Ampere characteristic of throttles of the form (i; where C 2 ± f is the ratio / Oy ' in maximum power mode. A decreasing henry-ampere characteristic of the throttle filter can be obtained by performing a magnetic core choke with a magnetic gap, the saturation of the material of the magnetic gap is less than the saturation induction of the core material, or the gap must be filled with a ferromagnetic material with a cross section decreasing along the gap. Fig. 2 is a falling Henry-ampere characteristic of the filter cross-over; in Fig. 3 a magnetic section with a gap filled with ferromagnetic material in Fig. 4 is a magnetic section with a gap filled with ferromagnetic material with a variable cross-section along the length of the gap. The circuit (Fig. 1) contains the main valve 1 (thyristor), non-return valve 2 (diode), switching capacitor 3, switching choke 4, load 5, filter choke with incident Henry-ampere characteristic, where Lg is the dynamic inductance of another filter 6, Dg- constant input current component. The magnetic core contains rods 7 and 8, a gap 9. The inverter operates as follows. In the initial state, the capacitor 3 is charged with polarity indicated in the drawing. When a control pulse is applied to the thyristor 1, the capacitor 3 is discharged through the switching choke 4, the load resistance 5 and the gates 1 and 2. The parameters of this circuit are selected such that the discharge current has a vibrating form. Then the reverse half-wave of this current creates a direct voltage across diode 2, which is blocking for thyristor 1, therefore, at the end of the oscillating current period, valves 1 and 2 are closed. After that, the input current through the filter choke charges the capacitor 3. When the next control pulse is applied, the processes are repeated. When the power is regulated downwards, the constant component of the input current drops, the dynamic inductance of the filter throttles increases, which leads to a decrease in the variable component of the input current. When a low input power level is reached, the inductance increases even more abruptly, which reduces the lower threshold for controlling the ms value. When performing throttles with a gap in FIG. 3, the Henry-Ampere characteristic is determined by the material of the gap, in the embodiment of FIG. 4 of its configuration. The use of the invention allows to simplify the converter, since it eliminates the need for a saturation throttle, which is achieved by increasing the value of the dynamic inductance of the throttle filter while reducing the input currents, i.e. in the small ms mode. Increasing the value of dynamic inductance also makes it possible to reduce the amount of distortion in the supply network. The reduction in distortion is proportional to the ratio of the increment of the dynamic inductance at low currents to the inductance of the unsaturated saturation saturation of the known device and is, for example, when the gap is filled with ferrite, a value of 2-3. This ratio also determines the reduction of the lower limit of regulation. Consequently, a reduction in distortion and a lower limit of regulation of 2-3 times is achieved. Claim 1. A series inverter comprising an anti-parallel valve pair connected to the input terminals through a filter choke and a serial LC-chain connected to the output terminals, which, in order to simplify and reduce distortions in the mains, filter the choke is made non-linear with a Henry-ampere characteristic decreasing in the operating range of the input currents, which has the maximum negative slope with a current value corresponding to the low input power mode 2. In The apparatus according to claim 1, wherein the filter choke is provided with a magnetic core with a magnetic gap, wherein induction of saturation of the material of the magnetic

the gap is less than the induction saturation of the core material.

3. The inverter according to claim 1, in accordance with the principle that the filter choke is equipped with a magnetic core with a gap filled with ferromagnetic material with a section decreasing along the gap length.

Sources of information taken into account in the examination

1. USSR author's certificate No. 155222, cl. H 02 M 7/48, 1962.

2. USSR author's certificate number 687547, cl. H 02 M 7/515, 1979.

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