SU147631A1 - Multi-motor electric finishing units - Google Patents

Description

The subject of the invention is a multi-motor electric drive for finishing units with unregulated driving current by DC motors powered from a three-phase network via individual semiconductor rectifiers. As in the known multi-motor drive circuits, these motors are controlled by changing the voltage of the rectifier at assistance booster bias transformers, which are controlled by compensator rollers position sensors.

A special feature of the proposed drive is the use of a control transformer common to all motors, which makes it possible to reduce the power of these booster transformers.

FIG. 1 shows a circuit diagram of the proposed multi-motor drive; in fig. A 2-prong circuit for controlling the current of the damping of the booster transformer from a rheostat sensor.

Independent drive direct current drive motors D /, D2, DZ, D4 are fed through individual solid rectifiers В, В2, ВЗ, 84 and booster transformers ВТ-, ВТ-2, ВТ-3 from the common feeder of three-phase current.

The voltage of this feeder can be regulated by means of a common regulating transformer (autotransformer) AT, smoothly or in steps, which makes it possible to set one or another base speed, and also reduces the starting current of the unit.

The booster transformer (Fig. 2) is an automagnetising autotransformer, allowing the core voltage U of each motor to be adjusted in small limits (± 5%), depending on the magnitude of the bias current.

No. 147631-2. The latter is controlled by an appropriate resistive or inductive sensor associated with the movable compensator roller of this machine. The unit is started to dry by turning on the supply feeder first for a lower and then for such a working voltage of the unit.

When the speed of one of the motors is not matched, the corresponding compensator roller (C, K2, CZ) rises or falls, thereby changing the excitation of the corresponding booster transformer, and consequently, the DC voltage applied to the core of this engine. .

As a result, the speed of rotation of the machine changes accordingly and is consistent with the speed of the machines adjacent to it.

The stiffness of the mechanical characteristics of the individual motors of the proposed drive, controlled by the root voltage, is kept constant at all speeds. Therefore, the range of adjustment that corresponds to the two extreme fields of the compensating roller may be limited to a small value, on the order of + 5%, which greatly increases the stability of the system and reduces the power of the booster transformer.

The drive maintains stability at any speed, i.e. at any network voltage of three-phase current, since a decrease in the core voltage does not reduce the effectiveness of the core control by additional voltage transformers.

These transformers and solid rectifiers of each of the drive motors, as well as the common control transformer, are located in control stations and installed directly in the workshop, near the respective machines, without requiring special premises and continuous monitoring by the operating personnel.

Subject invention

Multimotor electric finishing units with fixed downstream drive motors DC current fed from the three-phase network via individual semiconductor rectifiers and controlled by varying the supply voltage rectifiers using booster bias transformers which are controlled by position sensors compensatory rollers, wherein that, in order to reduce the power of booster transformers, an adjusting transformer.

Compiled by L. O. Soltz

Editor L. N. GoltsovTechred A. A. Kamyshnikova Corrector A. Bleus

Sub. to pec. 25 / VI-62 g. Format boom. 70Xl08 / 6 Volume 0.26 ed. l

Zak 6788 Circulation 1050. Price 4 con.

 TsBTI Committee for Inventions and Discoveries at the Council of Ministers of the USSR

Moscow Center, M. Cherkassky per., D. 2/6.

Printing house TsBTI, Moscow, Petrovka, 14.