| Induction heating power is widely used in industry with its character of highefficiency, energy saving, environmental protection and security, and the capability ofits control system directly affects the security of industrial production and outputpower. By studying the induction heating power control technology, design of theinduction heating power with excellent control properties, and the result can be paly apositive role in industrial production.Firstly, by analyzing the principle of induction heating, and comparing differenttopology structure and power modulation, the paper establishes the series resonant andPFM power modulation which were being used in induction heating power.Secondly, by analyzing the inverter working state on the series resonant and PFMcontrol, the research obtain that the inverter will slide from inductive to capacitive areathrough the resonance points and accompanied with bridge short-circuit phenomenonin the process of output power reach the peak with frequency regulating. We cangoverning the relationship between frequency and phase angle to protect the inverter.In the process of obtain the phase angle by engineering method, using PWM signal andcurrent signal to get the phase, that can simplify the design of hardware circuit, andthen propose induction heating power using PFM control with limit phase areastrategies.Thirdly, a series induction heating power which base on DSP TMS320F28335isdesigned in this paper by PFM control with limit phase region strategies, these includethe design of hardware and software units. The hardware units’ design include theprimary loop, control circuit, and drive circuit. The software units’ design include mainprogram, interruptive processing and corresponding subprograms. Finally, the hot-melting pot heating experiment was set on the induction heatingpower, the results show that the system running normally and provided a function ofPFM control with limit phase area, also the corresponding heating efficiency isavailable through experimental data. |
