Development Of Solid High Frequency Power Supply For Induction Heating

Power supply for induction heating is an equipment to heat the workpiece by whirling current and it is applied widely in industry because of its many virtues. Now,intermediate frequency power supply is perfect.but high frequency power supply has defects in the aspects of frequency and capacity and so on.So high frequency power supply is developed in this thesis.Firstly.operation principle of induction heating is introduced and the actuality of the power supply for induction heating is summarized.Then,the scheme of structure of the power supply is established: uncontrolled rectifier and Buck chopper constitute DC circuit.In this part, operation principle of a kind of soft switching Buck chopper is presented mainly and the conclusion that the power semiconductor devices operate in soft switching is also illustrated by analysing the operation principle of all stages; Series resonant inverter is selected as inverter circuit via comparing the advantage and shortcoming of parallel resonant and series resonant.Moreover.the work principle of series resonant inverter is analysed and the calculating method of the best dead time is put forward as well. At the same time.some new development of inverter is enumerated in this thesis.In the realization of the inverter control circuit,the signal from the PLL is input to IR2110 via adjusting phase and forming dead time.SG3525 is selected as the core device of the chopper.meanwhile.two pulse that will input to the chopper can be obtained by simple design.Besides.the circuit of which core chip is DSP is described.Finally.there are experiment results in the last part of the thesis,and much of experiment wave is used for validation of the theoretical analysis.