SU669459A1 - Self-sustained inverter - Google Patents

Description

(54) AUTONOMOUS INVERTER

one

The invention relates to a converter technique and may find wide application in the technique of induction heating of metals.

Known multi-bridge autonomous inverters with counter diodes 1 and 2 are known.

Their disadvantage is a relatively low output voltage, as well as an increase in the voltage across the inverter valves when a high voltage is applied to the load by increasing the voltage of the power supply.

A multi-bridge autonomous inverter with counter-diodes is also known, allowing you to get a high voltage across the load 3.

Its disadvantages are the availability of the required number of isolated power sources, as well as the execution of additional conclusions in the load.

The purpose of the invention is to increase the output voltage of the inverter without increasing the voltage on the valves, as well as expanding the frequency range while deeply regulating the output voltage of a new torus.

To achieve this in a standalone inverter, serious, but at least.

four valve bridges with inverse1 1 mn diodes and commutated. lC-KOHTypaNUi on the diagonal of the alternating current, the anode and cathode outputs of the bridges are connected in pairs in pairs and through the half windings of the filter chokes are connected to the terminals of one power source, the output leads are formed by common connection points of the said half windings of chokes (i.e. with one of the permanent terminals current, at least two extreme valve bridges. Output pins are formed by common points C1) uniquely, 1 windings of filter chokes with one of the outputs of the constant current of four extreme bridges, which are Yelnia chain bridges two groups working with neremenshim retllirovani angle.

The author proposes a new multi-bridge autonomous inverter with nitnioma from a single low-voltage source, which makes it quite easy to get any regulated voltage on the load, not a new voltage on the inverter valves, but this does not require the output of the voltage. This goal is achieved due to the fact that in a multi-bridge inverter, the paired bridges are connected through the half windings of the filter chokes to the power supply and form a series circuit for the flow of alternating current, and in that the circuit between the common connection points poluobmotok filter chokes to one of the DC terminals of the two extreme axles load included. FIG. 1 is a schematic diagram of an inverter; in fig. 2 - the same, one of the options, providing a wide range.

The inverter consists of bridges 1, 2, 3, 4, 5, 6, each of which contains thyristors, 7, 8, 9, 10, diodes 11, 12, 13, 14, switching capacitor 15, inductance 16, load 17, included between the anodes of bridges 1, 6, and input chokes 18, 19.

The inverter (see Fig. 2) consists of similar bridges, the load 20 of which is connected between the anodes of bridges 1, 5, 21, 22 and input throttles 18 and 19.

The inverter operates in steady state as follows.

At each moment of time, the current is conducted by thyristors of one bridge and oncoming diodes of others. As a result, the oscillating current of the bridges, equal to the load current, closes through the load, the thyristors and the counter diodes of the bridges, and the voltage across the load will be equal to the sum of the output voltages of the paired groups of bridges.

The operation of the inverter (see FIG. 2) is identical to the operation of the inverter shown in FIG. one.

Bridges within each group 2, 3, 4, 5, 6, 21, 22 operate with a constant shift of 180 el. hail., and bridges 1, 2, 3, 4 relative to bridges 5, 6, 21, 22 work with adjustable shear from 0 to 180 e. hail. As a result, the load voltage is controlled from 100% to zero.

With such switching on of bridges and loads, the voltage on the load will be proportional to the sum of the voltages on the switching capacitors of all the bridges and in this case will be three times higher than in the known circuits. If it is necessary to obtain a higher stress on the load, the formula of the invention

Claims (3)

1. Autonomous inverter containing at least four valve bridges with reverse diodes and switching LC circuits in the diagonal of an alternating And the current, the anode and cathode leads of the bridges are pairwise connected to each other and through the half windings of the filter chokes are connected to the leads of a single power source, characterized in that, in order to obtain an increased voltage equal to n Ly, where n is the number of pairs of bridges; U is the power supply voltage, in it, the output pins are formed by the common points of connection of the said half windings of the filter chokes with one of the direct current pins of at least two extreme valve bridges. 2. An autonomous inverter according to claim 1, characterized in that, in order to expand the frequency range while deeply regulating the output voltage of the inverter, the output pins are formed by the common points of connection of the half-windings of the filter chokes with one of the direct current pins of the four extreme bridges that are included in the series circuit of two groups of bridges. p working with variable angle of adjustment. Sources of information taken into account in the examination 1. USSR author's certificate No. 286043, cl. H 02 M 7/515, 1975. 2. USSR author's certificate number 399038, cl. H 02 A-l 7/515, 1971. 3. USSR author's certificate number 547948, cl. H 02 M 7/515, 1977. nor connect the required number of adjacent pairs of bridges. It should be noted that, at the same time, the voltage across the inverter thyristors remains practically unchanged. Thus, the possibility of obtaining an overvoltage at the load while maintaining the lower values of the voltages on the thyristors of the inverter and powering it from one source and the possibility of adjusting the output voltage from 0 to 100% is a significant advantage of the proposed device compared to the known ones.