Electromagnetic Continuous Casting Of Improved Composite Magnetic Field Control System Design And Research

Aluminum electromagnetic casting-rolling is a high and new technology with high efficiency and less energy-consuming. Aluminum crystal is refined and casting-rolling strip's performance is improved by introducing special electromagnetic field into continuous casting-rolling zone to change solidification and crystallization condition for molten aluminum.In order to solve defects of electromagnetic field control system, some important improvement is made. Matrix Convertor (MC) is adopted to design the main circuit, and current is selected as controlled parameter. And a closed-loop output current control method based on the space vector modulation is designed. So that current is forced to trace reference and good control performance is obtained.The software and hardware schemes of control system are researched in the paper. "DSP+CPLD" architecture is control core. Modularization design philosophy is adopted in design of periphery circuit and some modules are emphasized in the paper, such as input process module of analog signals, communication module and human-machine interface module, etc.Because of difficulties in modeling electromagnetic induction set precisely, self-adaptive PID control arithmetic base on Genetic Algorithm (GA) is adopted to optimize the PID parameters. By turnning on or off the software switch to active or inactivate the optimization, which has advantages of saving CPU resource and convenience when debugging. Simulation results show that self-adaptive PID control arithmetic base on Genetic Algorithm can effectively improve dynamic performance of control system and get better control effect than routine PID and fuzzy self-adaptive PID control arithmetic.Embedded real-time operation systemμC/OS-Ⅱis improved to build the structure of control system' s program to switch between tasks real-timely, assign resource properly, and to build a thick foundation in secondary design. Current waveform generator which is realized by software is researched and proved true by simulation. Establishment of communication protocol and design of CAN/RS485 communication software are also introduced in this paper.Experiment results show that the improved system can improve the quality of aluminous material dramatically.