SYSTEM FOR FEEDING AND CONTROL OF POLYPHASE AC CONVERTER-FED MOTOR

摘要

A system for feeding and control of a polyphase ac converter-fed motor is proposed. The polyphase ac converter-fed motor consists of several reversible controlled rectifiers, their inputs are connected to an AC network, blocks controlling the reversible rectifiers, current sensors and a controlling line for master control provided with a feed back sensor. In order to ensure constant shapes and phase-shift angles of currents and voltages during operation with different rotation velocities and different output power and in order to increase operation reliability, every phase of the polyphase ac converter-fed motor is connected to the dedicated reversible rectifier and has the current sensor. In the proposed system the frequency of the feeding AC network is several times higher of the emf frequency of the polyphase ac converter-fed motor and the controlling block is capable to ensure a specified shape of current and phase-shift angle for every phase and to set amount of the current providing equality of the currents of all rectifiers and minimum value of the error signal through the controlling line.