Intermediate Frequency Induction Heating Intelligent Controller

With the conception "Industry 4.0" put forward, China has taken an active part in and accelerated the development of science and technology industrial. At present, the traditional induction heating controller adopts the system mode of the analog control device combined with the classical control strategy. There are many shortcomings in the control process and the output effect Thus, it is of great value to design a digital and intelligent controller for improving the induction heating controller control effect and efficiency.Aiming at the problems of temp,erature drift, circuit complexity and poor stability in the traditional induction heating controller, and the general control method in the heating process,the temperature nonlinear time-varying problem can not be improved effectively. In this paper,the 90kW/lkHz intermediate frequency induction heating half-Topology algorithm is studied,and its working characteristic is canalyzed. A Complex power regulation algorithm based on FPGA is proposed, and the feasibility verification and model design and testing are carried out in Simulink. The specific work is as follows: Firstly, the operating mode and load characteristic of half-bridge series main circuit topology is analyzed and a power regulation strategy combined pulse width and pulse frequency is put forward. Secondly, the induction heating system model is built in Simulink envirornment. Phase-locked loop and fuzzy-PI multi-modal control algorithm is proposerd that to achieve the induction heating power adjustment. At the same time, the effects of the traditional PI algorithm and the fuzzy PI multi-modal algorithm on the system control are compared. The result shows that fuzzy-PI multi-modal control algorithm is the feasible and it has superiority on steady, celerity,accuracy and anti-interference. On this basis, The main circuit parameters are calculated and the trigger control system is designed based on FPGA controller, The hardware module has been tested including FPGA smallest system, A/D acquisition module of feedback signal,separated excitation to self-excitation boot module, adjusting module of feedback signal,isolation drive and protection module. Finally, the pure logic device is used in the software to achieve the phase-locked loop signal tracking function, and NIOS ? is used to achieve power closed-loop regulation in the Qsys system.Based on the above hardware and software design, experimental prototype is set up to test intermediate frequency induction heating series half-bridge intelligent controller and debugging of project is completed. Experimental results show that the topology of half bridge series circuit adopts composite power control strategy, realizes frequency tracking and constant output power control, improves power factor, reduce the power loss of the switch,the system has stronger robustness and adaptability. It has certain reference significance to the development of the intermediate frequency induction heating smelting industry.