Frequency Conversion Control Research Of Electromagnetic Vibrating Feeder

This thesis topic mainly studied a new type of electromagnetic vibrating feederexcitation mode and control mode. Electromagnetic vibrating feeder as a commonfeeding device, with its low operating cost, long service life and many other advantages,widely used in metallurgical, coal chemical, light industry and grain industry etc.Atpresent the main excitation method of electromagnetic vibration feeder is the thyristorhalf-wave rectifier. In this excitation, the large feeder will appear some problems suchas the regulating of inherent frequency is inconvenience, the efficiency is low, theharmonic pollution of power grid ect. Focusing on above problems and by means offrequency conversion technology, this topic make a in-depth study the electromagneticvibrating feeder way of three-phase rectifier invert excitation method and frequencyconversion control mode.At the fiest, this paper established the mechanics model of electromagneticvibrating feeder. on the base of studing the kinetic parameters and electromagneticparameters of large electromagnetic vibrating feeder, this paper introduced the processof three-phase rectifier invert excitation and the principle of the best vibration frequencycontrol which based on Lag Phase Angle Measurement.This topic focus on projected and finished the three-phase rectifier invert excitationcontrol system. Discussed the current surge of electromagnet coil under the effect ofdirect current. And designed a special PWM signal generating circuit consist of squarewave generating circuit, phase-locked double frequency circuit andpulse width triggercircuit. In order to achieve high power output, this article used the excitation circuitwhich put the three-phase rectifier filter as a preceding stage and the high power IGBTinverter as a backward stage. Designed protection circuits including over-voltageprotection, over-current protection, start up protection, ensure the stable operation of theIGBT main circuit. This paper also designed the real-time monitoring system which including signal acquisition circuit and display interface programming.Finally, Completed vibration experiment on the basis of the hardware and softwaredebugging success. Proved the three-phase rectifier excitation frequency and frequencyconversion control method, which made a significant effect in improving workefficiency, enlarging the frequency range, enhancing real-time control, is feasible.Achieved the expected goals.