SU79613A1 - DC to three phase converter - Google Patents

Description

The subject of the invention is a DC-to-three-phase converter, consisting of a switch, a rotating collector of a special design and a three-phase transformer.

In the known converters of this kind, the windings of the three-phase trapsformer are turned on by a star and connected to three collector brushes, the lamellae of which are connected to the poles of the direct current source.

The proposed converter is more perfect because it provides a closer approximation of 4) the form of the AC voltage curve to the sine wave.

This is achieved by a special arrangement of brushes on the collector and a selection of the appropriate insulation width between its lamellae, so that with each turn of the collector, the transformer windings are switched in various combinations.

The drawing shows a schematic diagram of the converter.

The electric motor / drives the rotation consisting of

two rings 2 and 3, the switch and the collector 4, sitting on the OlT, wah .ly. Rings 2 3 are isolated from the shaft. The collector 4 consists of two metal sectors or .camera 5, separated from each other with a solid insulator 9. On the collector 4, brush S, connected to the taps of the windings of the 1 phase transformer 7, 1c;

The width of the insulating layer of the col- lector is chosen such that, at a given diameter of 3sol.

The collector should have on each pair of lamellas three shch. In the insulator 9, the width of the insulator 9 between the lamellas is chosen to be 30 electrical degrees (without taking into account the 1 pyrine brush).

With the specified location HieTOK 8 and the width of the interlaminar insulator 9 at each turn

collector pa 30 electrical degrees will switch the windings of the transformer, providing different combinations of serial and mixed connections, helping to bring the shape of the voltage curve or the output of the transformer 7 to sinusoidal.

The capacitors b, connected at the output of the transformer 7, serve to compensate for the receiver's reactive power and at the same time to improve the output voltage crank.

The frequency of the alternating current is determined by the speed of rotation of the motor.

With one loop, the collector's d.h.: 1 but 50 hz frequency receiving gear requires that the motor / rotates at a speed of 3000 rpm.

If you increase the number of lamellae and, accordingly, the number of insulating layers of the collector and nget current 8, then the frequency of alternating current at TOII will increase by the same amount

Same speed 9; 1 electric engine.

Subject invention

DC to three-phase converter consisting of a switch, a rotating collector and a three-phase transformer with windings connected with a star and having faults connected to three (for each breaker bar) brushes; current, so that, in order to approximate the shape of the alternating voltage curve to the sinusoid, the brush collector is positioned at a distance of 120 electrical degrees from each other, and the width of the insulation between the lamellae p selected It is equal to 30 electrical degrees (without taking into account the brush brush) so that during each turn of the collector by 30 electrical degrees, the transformer windings are switched in different combinations of power and mixed power.