SU138993A1 - Device for controlling an adjustable AC drive - Google Patents

Description

The invention relates to phase control systems for two asynchronous motors operating on a common shaft, using a static zero phase shifter device according to the author. St. No. 101655.

In a related invention, a device for controlling an adjustable AC drive is provided.

A device for controlling an adjustable AC drive consisting of two asynchronous motors with a phase-rotor operating on a common shaft, with a series connection of the rotor windings is known. The stator winding is powered by one of the electric motors directly from the mains, and the other from the static phase regulator. Also known are devices for controlling electric drives of this type, but with a double (having a two-pack stator) short-circuit asynchronous electric motor.

Phase shifters used in these systems had low efficiency. and the electric drive as a whole had low technical and economic indicators.

A distinctive feature of the proposed device is that, in order to improve the technical and economic performance of the drive and improve its adjusting properties, a chorustam efficiency factor is used as a phase regulator. zero static phase shifter.

FIG. 1 shows the electrical circuit of the device; in fig. 2- twin motor design with short-circuit rotor.

Two asynchronous electric motors 1 and 2 with a phase rotor operate on a common shaft. The windings of the rotors of these motors

No. 138993, - 2 are connected in series. Winding Cs Ca, Sz stator motor / connected directly to the AC network.

The winding C4, Cs, Sat of the stator of the electric motor 2 is connected to the network through a static zero phase shifter.

The static zero three phase phase shifter is made up of three single phase phase shifters 5, each of which is a combination of three reactances connected in a star (the elements of the phase shifter are not shown in the drawing).

One of these resistances is a saturation inductor, the change in inductance of which leads to a purely phase change in the output voltage. By changing the magnetisation of the saturation chokes of single-phase phase shifters, the phase of the track-phase voltage system feeding the stator of the electric motor 2 changes. This change is equivalent to turning the stator of the electric motor 2 and leads to a change in the rotation speed of the electric drive.

The static phase shifter can be composed of static capacitors and magnetic amplifiers manufactured by industry.

The proposed device can be used to control a double short-circuited electric motor (Fig. 2).

In the housing 4 of such an electric motor are placed two stator 5 and b with the same winding and structural data. The common rotor has two separate packages 7 and 8, in which the short-circuited winding rods are laid. The rods are connected by short-circuited rings on the outer torpas of the rotor packages. Due to this, two emfs are induced in the rods of each packet. from stators 5 and (5.

By rotating the phase of the rotating magnetic field with one static phase shifter in one of the stators relative to the field of the other stator connected directly to the network, the speed of the electric motor can be adjusted.

Subject invention

Claims (2)

1. A device for controlling an adjustable AC drive consisting of two asynchronous motors with a phase-rotor operating on a common shaft, with a series connection of the rotor windings and powering the stator winding of one of the motors directly from the network, and the other from a static phase regulator, different By the fact that, in order to improve the technical and economic performance of the drive and improve its regulating properties, a zero static phase shifter according to the author was used as a phase shifter. St. No. 101655. 2. Use of a device according to claim 1 for controlling a dual adjustable short-circuited asynchronous motor. 68