Design Of Induction Heating Power Supply Based On Full Digital Phase-locked PWM Adjustable Power

The research object of this paper is induction heating power supply. The paper introduces the basic principle and characteristics of the technique of inductive heating, then describle the development and trends of induction heating power supply. Compared with the advantages and disadvantages between the series resonant inverter circuit and parallel resonant inverter circuit, series resonance circuit is more suitable to be supplied as topological structure of this project combining subject. The paper also analyzes the load series resonance tank circuit and its three kinds of working condition.Based on output power 16 kW induction heating power supply, this paper completed the main circuit parameter calculation and selection of various components, this paper also achieved the designs of control the peripheral circuit, including the designs of zero comparing circuit, amplitude transform circuit and over-voltage under-voltage protection circuit.In this paper, the control system combines DSP with FPGA, the main control system in FPGA, DSP is mainly responsible for delivering the data to the FPGA. The control system of induction heating power supply in this paper uses full digital lock together two dimensional control of PWM adjustable function, in other words, through adjusting the output frequency and output PWM duty cycle, it completes the phase-locking and power regulation. To ensure the induction heating power supply can work in weak inductive zone, Phase-locking and adjustable work all adopt incremental digital PI algorithm. In addition, switch desktop module is designed to avoid having bad problem during the process of the induction heating power supply start-up and shutdown. DSP will feedback and deal the current operating frequency date to FPGA, and transmit to the display panel. Using the internal McBSP of DSP, it completes data communication between the DSP and FPGA.Finally, the function of each module test and feasibility of the entire control system is completed and verified by building an experimental platform. Then the experiment of iron bar heating is success under help of building a real machine test platform, Experiments show that the design of all digital phase-locked PWM modulation power induction heating power supply can work in the weak perceptual area and power can be adjusted.