SU1684888A1 - D c to a c three-phase mechanical converter - Google Patents

Abstract

FIELD OF THE INVENTION The invention relates to electrical engineering, in particular, to direct current / alternating current converters. The aim of the invention is to simplify the design of the converter. The mechanical converter of direct current to alternating three-phase current contains three current-collecting terminal sectors, isolated from each other, two brushes touching these sectors, which are diametrically opposed and connected to the direct-current network. Token-ring sectors are mounted on the converter shaft coaxially with respect to an angular shift relative to each other of 120 ° C. In addition, contact rings are installed on the shaft, each of which is electrically connected to one of the collector ring sectors and each of which is provided with a contact brush connected to an AC network. 2 Il. WITH

Description

The invention relates to electrical engineering, in particular to mechanical current transducers — collector devices of electric motors and generators, and can be applied to current transducers in electric power supply circuits of electric motors.

The purpose of the invention is to simplify the design of the converter.

FIG. 1 is a schematic diagram of an AC-to-three-phase current converter; in fig. 2 - diagram of a three-phase collector converter

The current converter consists of an electric motor 1, on the shaft 2 of which a collector converter 3 is installed, which consists of a phase collector ring 4 and two or three collector rings 5. The phase collector ring consists of three sectors 6. isolated from each other For three-phase converter sectors phase collector ring is set with a shift of 120 °. All collector rings are fixed on the motor shaft rigidly. The distance C between the sectors of the phase collector ring is 2-3 mm greater than the width of the electrobrush. This is necessary

| 0 00 b. CO 00 00

for that. to avoid sparking on the collector and the short circuiting of the sectors with brushes.

DC current is supplied to the converter through brushes 7, which distribute the current to the collector sectors 6 Each collector sector is connected to an insulated ring 5, insulated wire 8. AC voltage is removed from the collector ring by means of a brush 9. Brushes 9 are connected by wires 10 to a consumer mi AC.

The current transducer works as follows.

Before turning on the converter, turn on the electric motor 1, operating on a direct current. Then a constant voltage is applied to the brushes 7 of the converter. The current transducer can produce an industrial frequency (50 Hz), a frequency of 200 or 400 Hz. For the required frequency, an appropriate gearbox can be used, mounted on the motor shaft. For a frequency of 50 Hz, the electric drive must have 1500 rpm. As can be seen from the three-phase collector circuit, the NL each sector b is supplied with the voltage of one sign, half a turn the sign of the voltage changes to the opposite. Therefore, for one half of the shaft turn (period) on the brush 9 there is a rectangular pulse of voltage of one sign, and for the other half of turn there is a rectangular pulse of opposite sign (Fig. 1 and 3). So in each

The phase (L, B and C) is alternating current of rectangular pulses with a phase shift of 120 °. However, such alternating current, instead of traditional sinusoidal pulses, is used to power small aviation and car consumers of three-phase current (H 200; 400 Hz), for example, artificial horizon, pointer of heel and slip, radio equipment, etc. Taking into account the fact that the load has an inductive resistance, rectangular impulses take a sinusoidal shape when the consumer is working.

Efficiency of the proposed converter

reaches 80-85%.

The proposed converter, compared with the known one, is simpler in design, more economical, has less weight and has EShKO reliability.

Claims (1)

Invention Formula Mechanical DC / AC converter to three phase current, containing tokosyomnyy ring sectors, isolated from each other, two brushes relating to these sectors, located diametrically opposite and connected to a DC network, differing in that, in order to simplify the design, the number of current-collecting ring sectors is equal to three, they are set to the shaft coaxially and with an angular shift relative to each other, equal to 120 °; in addition, a gripping rings are installed on the shaft, each of which is electrically connected to one of the current-collecting ring sectors and provided with a contact brush connected to the network alternating current, /, L 2