SU120566A1 - Synchronous motor compounding device - Google Patents

Description

The proposed device for compounding a synchronous motor driven by an electrical exciter is of a known type of devices of the same purpose, containing a rectifier whose input is connected through a magnetic amplifier to the secondary winding of the current transformer connected to the motor power supply circuit and the output is connected directly (t without the switches) to the excitation winding of the exciter.

In contrast to the known devices, which use a choke magnetic type amplifier, the proposed device uses a transformer type amplifier with biasing from two differentially operating control windings, one of which is connected in parallel to the control resistor in the exciter excitation circuit, and the second in series in the rectifier circuit. Met. This achieves a simplification of the device and provides an increase in the stability of the engine in case of accidental overloads and decreases in voltage.

The drawing shows a circuit diagram of the proposed device for compounding a synchronous motor.

The synchronous motor SD is excited by an electrically driven EM driver, the field winding of which is connected directly (without a switch) to the output of rectifier B. The input of this rectifier is connected through a transformer with bias PT to the secondary winding of the current transformer of the CT connected to the power circuit of the engine of the SD.

The transformer PT is magnetized by two differentially operating control windings, W i and y2

No. 120566-2 -

On these windings, parallel to the adjusting rheostat R is connected to the excitation circuit of the EM driver, another Wy2, sequentially to the output circuit of rectifier B.

Analysis of the proposed device shows that it. on the one hand, it reduces the extent of possible overloads of the engine during operating fluctuations of the mains voltage and the engine load, facilitating the work of the personnel on duty, and, on the other hand, increases the stability of the engine with reduced mains voltage and overloads.

The use in the proposed device of a transformer with bias instead of the chokes used in the known devices allows the selection of the transformation ratio so that in emergency conditions (at a ratio of 1.5-2.0 stator current), the engine will be forced to gives relay boost forcing. In the normal mode, due to the strong bias of the transformer, the primary current / is mainly magnetizing and the output current / 2, and consequently, the current of the BiB i i If are small; therefore, the motor drive current does not exceed the nominal value. Thus, the device is potentially prepared for forcing a motor drive. When the magnetizing current decreases in emergency conditions, there is a sharp increase in the excitation current of the engine.

The use of the additional control winding (bias) W, connected in the main winding W 1, on the transformer DC allows the proposed device to be used for the purpose of forcing a motor that operates with shock and jog-like loads under normal mains voltage. This provides the possibility of a significant increase in the overload capacity of the engine due to the higher rate of rise of the excitation current compared to the relay forcing of the excitation.

With a decrease in voltage and a sharp increase in load, the magnetizing current in the transformer decreases inertia-free and falls lower than would be the case with slower processes, thus achieving an inertia-free increase in the intensity of compounding the motor excitation.

The proposed device, improving the synchronization of the engine under load, makes it possible to extend the range of application of simple starting circuits with a deaf connection of the exciter to the rotor according to the starting conditions and thereby reduce the cost of the engine control equipment, its installation and commissioning.

Subject invention

A device for compounding a synchronous motor, driven by an electromachine exciter, containing a rectifier, whose input is connected through a magnetic amplifier to the secondary winding of a current transformer connected to the motor power supply circuit, and the output is connected directly (i.e., without switches) to the exciter winding of the exciter, characterized in that, in order to simplify the device and increase engine stability, a transformer with bias oj of two differentially active control windings, one of which is connected in parallel to the adjusting rheostat in the excitation circuit of the exciter, and the second is sequentially connected to the rectifier circuit.