Category: Transport control systems

Authors:

Kovkin A. N.

Annotation:
Issues related to the use of converting schemes were considered in the article; the latter form three-phase alternating voltage in order to conjugate supervisory computer control system of computer-based interlocking control with electric drives of station switches, equipped with three-phase asynchronous alternating current motors. Modern trends for power electronics were examined at the beginning of the article particularly concerning the development of electric energy transducers and frequency-controlled electric drive. Problems related to the use of frequency-controlled drive for remote electric machinery control were stated. Specific requirements for point machine control on railway transport were formulated in course of presentation of basic material. Moreover, the appropriateness of pulse-width modulation disuse, as well as application of invertors as conjugation facilities, requiring low-frequency operation of switching elements, was justified. A scheme of bridge invertor performed on the basis of insulated-gate bipolar transistors was examined; the former carrying out the formation of stepwise rectangular voltage at motor windings. The requirements to electric power supply of invertors being part of conjugation facilities were also formulated. Particularly, constant voltage values at the output of the invertor, providing torque data similar to that in the current electric interlocking systems, were determined. Issues of practical realization of three-phase bridge inverters with low-frequency commutation based on current integrated circuit were considered. A solution providing optimization of timing parameters for semiconductor keys was suggested. Attention was paid to problems of concordance of the inverter as interface with multi-channel computational structures in railway automation security systems. A method of safe formation of control signals for power keys of the inverter, consisting in control signal generator usage, was introduced. It should be noted that the power supply of the latter is formed by means of a safe gate circuit

Key words:
Interface, functional generator, three-phase induction motor, invertor, low-frequency commutation, stepwise rectangular voltage, torque, insulated gate bipolar transistor, control signal generator


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