SU1534703A1 - Series inverter - Google Patents

Abstract

The invention relates to power converter technology. The goal is to increase reliability and improve weight and size. The device contains the main thyristors 1 - 8. Switching throttles 17, 18 are connected between the counter thyristors 13 - 16 and thyristors 2, 3, 6, 7, the windings of which are magnetically connected and connected according to. The control unit 19 simultaneously generates control pulses on thyristors 1, 6, 3, 8, 13, 16 and respectively on thyristors 5, 2, 7, 4, 14, 15. 1 c.p. f-ly, 2 ill.

Description

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The invention relates to electro-fexmuce, namely to power converter equipment.

The purpose of the invention is to increase reliability, improve weight and size indicators,

Figure 1 shows a diagram of a serial inverter; figure 2 - diagram of the inverter with the disks.

The series inverter (figure 1) consists of two chains containing rto four series-connected gates (thyristors) 1-4 and. 5-8, input droplets 9, two switching capacitors 10 and I, switched off between common points of connection of thyristors 1,2 and 5.69 and such 3.4 and 7.8, loads 12, connected rioft between common points of connection of thyristors 2, 2, 3, and 6, 7, four counter aristors 13–16, which are paired with t | o connected in series and counter-parallel to the chain of valves 1–4 and 5–8, two magnetically connected commutating chokes 17,18 and a control unit 19, the outputs of which are connected to the inputs of the respective thyristors. The inverter is powered from a direct current source with voltage C ,.

The series inverter (FIG. 2) is made identical to the inverter of FIG. Which has introduced two additional diodes 20 and 21 with a short recovery time. Diode 20 is connected between Common anodes of counter thyristors 4.16 and common cathodes of thyristors 4 and 8, and diode 21 - between common cathodes of counter thyristors 13,15 and Common anodes of thyristors 1 and 5,

Serial inverter (figure 1) in the steady state operates as follows.

Let the thyristors 1,6,3,8,13,16 unlock at a given moment of time determined by the control unit 19. At the same time, capacitors 10 and 11 charge

up to a voltage greater than U is the voltage of the power source with the polarity indicated in FIG. 1,

As a result, two flow paths of the oscillating current through the load 12: 1-10-6-12-17-13-1 and 3-11-8-16-18-12-3 are formed. The currents of these circuits in the load add up, and the frequency of the oscillating current is determined by the parameters of the elements of the oscillating circuit: capacitors

0

five

0

five

10.11 and chokes 17.18. After the oscillating current drops to zero, the thyristors 13 and 16 are locked, the input current flows through the input choke 9 and the thyristors 1, 6, 3, 8 and the load 12, recharging the capacitors 10 and 11 to a voltage greater than U. In the next clock cycle Inverter control unit 19 supplies control pulses to thyristors 5, 2, 7, 4, 14, and 15. As a result, thyristors 1.6 and 3.8 are turned off and two other oscillatory current flow paths are formed: 5-10-2-12-12-18 -15-5 and 7-11-4-14- 17-12-7, the processes in which are identical to that described. Further, in the next cycle of work, the thyristors 1, 6, 3, 8, 13, 16 are included and all the processes are repeated. Thus, an alternating current (voltage) flows through the load, but is close to the sinusoidal form,

The operation of the inverter of FIG. 2 is identical to that described for the inverter of FIG. It is distinctive that due to the inclusion of diodes 20 and 21 with a short recovery time, the reverse thyristors 13 16 are switched off at significantly lower values of the reverse current through them, and therefore through throttles

17 and 18. This allows significant coupling of switching overvoltages on the valves arising from the current interruption to the throttle x 17 and 18.

The proposed construction of the inverter significantly improves its reliability by increasing the recovery time, as well as the magnitude of the reverse voltage on thyristors. Improving reliability is also achieved by appropriately turning on magnetically coupled chokes, which makes it possible to equalize the recovery time of the thyristors by reducing switching surges due to the inclusion of diodes with a short recovery time. The inclusion of magnetically coupled chokes between the load terminals and common points with The coupling of the counter thyristors results in the reduction of their weight and size parameters, since only the oscillatory part of the load current flows through these chokes.

Claims (2)

Invention Formula I, A sequential inverter containing two chains, each of which consists of four valves connected in series, the anodes of the first and the fourth cathodes are combined and through the input choke under the chains in the opposite direction, each winding is connected between one of the output pins and the connection point of the corresponding pair counter-thyristors, and the control unit is made to form unlocking pulses of each counter-valve simultaneously with unlocking the keys are. to the input terminals, between the point of impulse of the main valve, the connections of the first and second chain valves and between the connection points of the third and fourth chain valves include the corresponding switching capacitors, and the points of the second and third valves are connected to the output pins, two pairs according to opposite-connected gates in series, two commutating throttles, the windings of which are magnetically connected and connected according to, as well as a control unit, characterized in that, in order to increase reliability and mass parameters, thyristors are used as all chain gates and counter gates, parallel thyristor pairs are included connected to the counter valve and part of the chain connected to this counter valve through the choke. 2. Pop-up inverter 1, characterized in that, in order to further increase reliability by reducing switching overvoltages on the gates, two diodes with a short recovery time are inserted in it, which are connected respectively between common cathodes of two opposite thyristors and common anodes the first valves of the chains, also between the common anodes of the two other counter thyristors and the common cathodes of the fourth valves.