The Control System Of The Induction Heating Power Based On The FPGA

Induction heating power has been used widely in industrial areas for the advantages of protecting environment and saving energy. The control method for inverter is crucial to determine whether induction heating power can work safely and efficiently. At present, the induction heating equipments mostly use analog control circuit. The analog control circuit has some disadvantages such as too much contacts, jointing points and low system availability. The analog control circuit has difficult in modifying the control parameter, and has low agility. During these years, with the development of the micro-computer, digital control is more precise. The design of the software is more agile and the whole control system is easy implemented.In this paper, a digital control system which based on the FPGA is designed based on the analog inverter control system.Firstly, the digital parallel inverter control system of the induction heating is researched. Based on the available documents at home and abroad on this subject, the inverter function modules, such as all digital phase-locked loop(ADPLL) and swept-frequency start circuit, are designed. They are based on the operating principle of the analog control circuit. Each modules has been analyzed with mathematics and simulated functionally. The results show the modules reach the function target and design requires.Afterwards, the whole operation process of the induction heating power is analyzed. The analog control circuit has difficulties in modifying parameter and has low agility. For this problem, the function modules such as data collection, save and display, are designed. This is propitious to system debug, parameter modify, and so on.Finally, based on the analog control strategy, the control demand and strategy of digital controller is also analyzed. The digital controller has been designed with the hardware Finite State Machine(FSM). With the top to down method, combine all modules and make a SOC system. Each part has been simulated and validated with the FPGA software. The result shows the design reach the requests of the inverter control and the man-machine operations.