SU74405A1 - Device for regulating the speed of an asynchronous motor - Google Patents

Description

The present invention relates to a yittipoficrBaM for controlling the speed of an asynchronous motor through a thyratron frequency converter connected via a train to the mains and connected to the rotor circuit of the engine.

According to the invention, in order to regulate the power ratio of a motor-nni motor, it is proposed to connect thyratron nets to a phase-mixing transformer connected to an adjustable roshor, tel.

In order to obtain the serial characteristic of a regulated motor, a regulated primary winding 1; pa; nspor1m of a tori supplying thyratrons is connected in series with the stator of the motor.

In the drawing, Lp1I1 is represented by the circuit diagram of the proposed device with a full-wave rectification of the current entering the rotor. With a one-half-wave period, the number of thyratrons decreases to six.

Each phase of the rotor of the engine 1 n "has four thyratrons 3, feeding the rotor through smoothing throttles 4.

The control of the nets of the thyratrono-pro- cedure is made of phase-mixing device against voltage on the rings (X of the rotor. As a result, each of the three groups of thyratrons supplies a current to the rotor whose frequency automatically coincides with the slip frequency.

The adjustment of the engine revolutions, as well as compensation, can occur from a phase-mixing transformer 6, in series with which resistance 5 is switched on to reduce the magnetizing current at low frequencies. The voltage removed from transformer 6 is transmitted through transformer 7 to thyratron meshes. {The drawing shows the connection for only one group of thyratrons; the remaining groups are connected similarly).

The parameters of the grid circuit - transformer 7 - transformer 6 - the rotor must be chosen so that, if the operating modes of the engine are changed, the stability of the engine is not affected.

When parallel or serial connection of the power transformer 2 to the network, the motor / will acquire shunt or serial characteristics.

171

The subject matter of the invention 1. A device for controlling the speed of an induction motor through a tiratron frequency converter connected via a transformer to the supply network and connected to the rotor circuit of the engine, characterized in that, in order to regulate the power factor of the engine, the thyratron grids are connected to a phase mixer: i tf .

,

to the transformer connected to the rotor of the regulated motor.

2. Modification of the device according to claim 1, characterized in that, in order to obtain a serial performance of an adjustable motor, the primary winding of the transformer feeding the thyratrons is connected in series with. stator motor.