SU777832A1 - Dc-to-ac voltage converter - Google Patents

Description

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 -777832

13-18, an inverter switching unit comprising p, distribution thyristors 19-24 and separation thyristors 25, 26, choke 27 and a condenser 28 (reactive elements), connected via thyristors 29, 30 to the iTitanium source, additional bottom 31 for connecting the switching unit to the power thyristor controller. In order to ensure the switching of the thyristor of the regulator in the intervals between the switches of the inverter, the device can be equipped with an additional recharging thyristor 32 connected in parallel with the reactive elements.

The Converter operates as follows.

Suppose that before the next switching, the currents flow through the thyristors 2, 7, 9 and 12, and the capacitor 28 is precharged from source 1 through the thyristors 29 and 30. For switching the current of the thyristor 7, the thyristors 20 and 25 are unlocked, while the discharge current of the capacitor 28 around the circuit: capacitor 28 - choke 27 - thyristor 20 - thyristor 7 - thyristor 25 - capacitor 28 - thyristor 7 locked. A further recharge of the capacitor occurs but the circuit: capacitor 28 - choke 27 - thyristor 20 - thyristor 13 - thyristor 25 - capacitor 28. When reducing the recharge current to the load current, diode 14 is opened, ensuring the flow of reactive current and reverse voltage in the switched phase load. At the end of the switching process, a control pulse is applied to the thyristor 8, which begins to conduct current after the reactive current of the diode 14 drops to zero.

Subsequent switching of the current of the thyristor 2 is provided when the thyristor 29 is unlocked. In this case, the thyristor 2 is locked by the circuit current: capacitor 28 - diode 31 - thyristor 2 - thyristor 29 - choke 27 - co-capacitor 28, and capacitor 28 recharges to the original circuit voltage: 28 - diode 31 - diode 3 - thyristor 29 - choke 27 - capacitor 28. When the overcharge current decreases to the value of the thyristor current of the regulator, diode 4 is unlocked, ensuring the transfer of the energy stored in the choke 5 to the capacitor 6. After the current switching is completed thyristor re the thyristors 29 and 30 are unlocked at the gullet, the dositor dispenses the capacitor 28 to the circuit: source 1 - thyristor 29 - throttle 27 - capacitor 28 - thyristor 30 source 1.

The unlocking of the thyristor 2 during switching is carried out with a delay determined by the law of voltage regulation at the output of the inverter.

The next switching of the currents of thyristors 12 and 2 is similar to that described. When the thyristors 23 and 26 are unlocked, the inverter 12 is locked by the loop current: capacitor 28 - choke 27 - thyristor 26 - tunneled switch 12 - thyristor 23 - capacitor 28, and capacitor 28 not cut along the circuit: capacitor 28 - choke 27 - thyristor 26 - diode 18 - the thyristor 23 is a capacitor 28. When the switching current decreases, the reactive load current flows through the diode 17. After the reactive current drops to zero, the thyristor 11 begins to conduct.

The thyristor unlocking switch 28 again switches the current of the thyristor 2. Thus, the controller operates with a frequency of 2tnf, where t is the number of phases of the inverter, and / is its

output frequency. When the inverter operates with a low output frequency, maintaining the high frequency of the controller (to reduce the mass and size parameters of the smoothing filter) can be ensured by additional switching of the regulator thyristor current in the intervals between the inverter thyristor current switches. To do this, the thyristor 32 is opened, the capacitor 28 is pre-recharged around the circuit: capacitor 28 — choke 27 — thyristor 32 — capacitor 28, and then when the thyristor 29 is unlocked, the current of the thyristor 2 switches, after which the capacitor 28 is charged through the thyristors 29 and 30 .

Thus, the connection of the inverter switching unit using an additional diode to the power thyristor of the regulator makes it possible to use the same

the same reactive elements for switching both the inverter and the controller, and in general, simplify the device.

Claims (3)

1. A DC / DC converter containing a series-connected DC voltage regulator and an autonomous voltage inverter, the DC voltage regulator including a power voltage circuit and a series switching circuit formed by a choke n capacitor, the first end of which is connected with the anode of the power thyristor with the help of a switching thyristor, the second is connected with the cathode of the power thyristor, and the autonomous voltage inverter contains a bridge of working thyristors, bypass reverse diodes, and distribution thyristors, characterized in that, for the purpose of simplification, the second end of the switching circuit is connected to the cathode of the power thyristor via an additional bottom, and both ends of the said circuit are connected to the corresponding distribution thyristors. 2. The converter according to claim 1, separately from the fact that the sequential switching circuit is shunted by an additional recharging thyristor. Sources of information taken into account in the examination 1. Sandler, AS, et al. Frequency converters on thyristors for controlling high-speed motors. - M. Energie, 1970. 2. Chizhenko IM and others. Fundamentals of transformative technology. - M. Higher School, 1974. 3. USSR author's certificate number 301801, cl. H 02M 5/42, 1969.