SU1001389A1 - Dc voltage converter - Google Patents

Description

(5) MULTIBLOCK INVERTER

The invention relates to electrical engineering and can be used in converter equipment. High-frequency thyristor inverters are known, made according to multi-cell circuits. 1 1 The disadvantage of such inverters is the poor use of thyristors in voltage, as well as a significant change in the voltage on the thyristors and the circuit time provided to the thyristors to restore their electrical strength due to changes in load parameters and frequency of oscillations generated. Similar drawbacks are inherent to inverters made according to multi-cell C 2} bridge circuits. Closest to the proposed is a high-frequency thyristor inverter, made according to the scheme of multi-cell inverters with reverse thyristors. Each cell consists of two series-connected main and two reverse thyristors, two chokes, connected in series with the thyristors, a switching capacitor and a multi-winding transformer, in which the number of primary windings is equal to the number of cells. The cathode of one reverse thyristor is connected directly to the anode of the main thyristor which is opposite to it, and the cathode of another reverse thyristor is connected to the anode of the other main thyristor connected to it through the primary winding of the output transformer. One plate of the switching capacitor is connected to the point of connection of the anode and cathode of the reverse type and of the resistance, and to one end of the primary winding of the transformer, the other end of which is connected to the point of connection of the anode and cathode of the main thyristors, the second plate of the capacitor is connected to the middle point of the filter capacitors, the power source, the second terminals of which are connected to the drossel 31310. The disadvantage of the known device consists in a substantial increase in the voltage on the switching capacitors, and consequently on the basis of overt and reverse thyristors, caused incomplete recharging of the capacitor switching house caused by increase in frequency of the oscillations generated during inverter operation in the frequency range, target invention - an extension of the frequency range generated by oscillations of a lot cheykovom thyristor inverter. To achieve this goal, there is a multi-cell inverter containing pits, each of which consists of two series-connected main thyristors connected to a power source through inductors, and two series-connected reverse thyristors, the common point of which is connected through the primary winding of a multi-winding output transformer common point of the two main thyristors, and through the switching capacitor - with the midpoint of the power source, the chokes are made with taps, and the reverse tiri Stores are connected to the tapes of the indicated chokes. FIG. 1 shows a diagram of the device; in fig. 2 - time diagrams of his work. The inverter contains main thyristors 1-0, reverse thyristors 7-12, chokes, switching capacitors, a power source with a midpoint 22, a multiwinding output transformer 23, a load 2 The inverter operates as follows. At each time point, the main and reverse thyristors of different cells 1 and 7, 2 and 8, 3 and 9, t and 10, 5 and 11, 6 and 12 are turned on. When the main thyristor 1 is turned on along the circuit: plus the power source, the choke 13 is the main thyristor 1 -. the primary winding of a multi-winding transformer 23 switching capacitor 19 is the middle point of the source (capacitors) flowing a sinusoidal current pulse i (Fig. 2d, solid line |). Capacitor 19 is recharged from negative voltage -U ((o) to positive voltage U 25). After the current pulse through the thyristor 1 is terminated, a reverse voltage is applied to it (Fig. 2c), equal to the voltage difference across the switching capacitor 19 at time t and half the voltage of the power supply U-, t then turns on SL I GPO thyristor 2 and the current pulse flows through the circuit: the middle point of the source 22, the capacitor 20 - the primary winding of the transformer 23 - the main thyristor 2, the choke 16 - minus the power source 22 (Fig. 2a, the negative current pulse - dashed line II). During the flow of current through the thyristor 2, a reverse voltage is applied to the thyristor 1. The following half-cycle includes the main and reverse thyristors 3 and 9. Turning on the thyristor 3 ensures the flow of the current pulse in the load of FIG. 2c |) | and thyristor 9 bit of switching capacitor 19 from the voltage flag from ,,. To Uj, (o) along the circuit: positive capacitor plate 19 reverse thyristor 9 - choke 13 - plus source E - middle point of the source (capacitors) - negative capacitor plate 19. In the conductivity interval of the reverse thyristor 9, a load voltage is applied to the thyristor 1. When the thyristor k is unlocked, the capacitor 19 is recharged from the value of U (0) to -and, h / g, g- –gnciX, (Fig. 26). In this device, since the reverse thyristors are connected to the taps, i.e. parts of chokes when the inverter operates in the frequency range, the switching capacitor has time to be recharged completely and the voltage increase on the capacitor and thyristors will not occur. Thus, the connection of the cathode of one reverse thyristor and the anode of the second reverse thyristor of each cell to the taps of chokes, i.e. their parts, connected in series, respectively, between the anode of one main thyristor and the plus of the power source and between the cathode of the second main thyristor and the minus of the power source, increase the frequency range of the generated oscillations. . Formula of the Invention A multi-cell inverter containing pits, each of which consists of two series-connected main thyristors, connected

S1001

to the power source through chokes, and two series-connected reverse thyristors, the common point of which is connected through the primary winding of the multi-winding output tran-5 reformer with the common point of two main thyristors, and through the switching capacitor - with the middle point, the power source, characterized in that in order to expand the frequency range of 10, the chokes are made with tapes, the reverse thyristors

89A

connected to the tapes specified chokes.

Sources of information taken into account in the examination

1.Artym A.D. Key generators of harmonic vibrations. M., Energie, 1976.

2.Berkovich E.I. and others. Thyristor converters of high frequency. L., Energie, 1973, p. 200

3.Avtorskoe certificate of the USSR | № 81972, cl. H 02 M, 1971

Claims (1)

Claim A multi-cell inverter containing η cells, each of which consists of two series-connected main thyristors connected 5 1001389 to the power source through inductors, and two series-connected reverse thyristors, the common point of which is connected through the primary winding of the multi-winding output transformer 5 with the common point of the two main thyristors, and through the switching capacitor with the middle point, the power source, characterized in that, in order to expand the frequency range of 10, the chokes are made with taps, and the reverse thyristors are connected to the taps of these chokes.