SU58842A1 - Device for reversing a high voltage asynchronous motor - Google Patents

Description

Device

The reversal of powerful asynchronous motors requires the presence of a special apparatus-reverser.

The conditions of operation of this apparatus are usually very heavy, since it has to break (or turn on) large currents and withstand enormous overvoltages.

A modern high-voltage reverser is a device of impressive size and is PRESENTLY expensive. Oil reversers are smaller, but unreliable and dangerous with regard to the possibility of explosions.

Thus, the problem of reversing powerful electric motors is not yet fully resolved.

The subject of this author's certificate is the idea of reversing asynchronous motors, as seen in the drawing, in FIG. 1 of which the circuit diagram of the device is shown, and in FIG. 2, an electrical circuit of the contactors control circuit is possible.

According to the invention, the star A of the stator of an induction motor fed from the R, S, T network includes one high voltage bipolar contactor III, which performs virtually all the work of turning the machine on and off. Since the potential difference in a star is normally equal to zero, and the currents of high-voltage machines are small, the danger of overlapping is much less and the conditions of the contactor's operation are relatively unreliable. The stator phase switching (reversing) is performed by a separate reverser I, P (air or oil). Since the entire reversal is placed on the contactor III included in the star of the stator, the operations of the reverser I and II are performed in the absence of current in the circuit. Thus, the size of the reverser is reduced. The entire control and reversal process is performed by a K controller with contact fingers 6, 7, 8, 9, 10. The reversing processes occur in the following order: 1) the commander controller in the O-Sun position is turned off; 2) the controller in position 1 — the first system I is turned on for reversing a high-voltage asynchronous motor. It was filed on May 14, 1939, in the NKEP for L 24009. Published January 31, 1941.

reverser contacts; 3) the controller in position 2 is turning on the contactor of the third star and the engine starts to rotate.

With the reverse movement of the handle, the process is reversed.

The dimensions of the controller segments are chosen so as to ensure a sufficient time interval between the switching on of the star contactors and the reverser. It is possible for this purpose to use the contacts Ilia, Illb in the contactor of the star and electrically block the bridge of the actor with the reverser, as shown in the diagram of FIG. 2

Both reverser systems cannot be simultaneously turned on, since they are interlocked by contacts 1a and Pa. Contact Ib. and the lib of the reverse system is included in the coil circuit of the contactor III, as shown in FIG. 2

Naturally, the control scheme also admits a number of other modifications while maintaining the principle itself without changes and ensuring the installation of all sorts of accidents associated with erroneous actions of the elements constituting the circuit.

The subject matter of the invention.

A device for reversing a high-voltage asynchronous motor by means of a reverser controlled by a commander, characterized in that, in order to reduce the size of the reverser, a two-pole high-voltage contactor interlocked with the contactors of the reverser in such a way that the reversal of the motor occurs on a stator winding when a switch is detected with a switch. the stator.