Development Of Ajustale Frequency Indoction Heating Power Supply Based On DSP

With the rapid development of modern power electronic technology, induction heatingtechnology is becoming perfect, it is not only applied to smelting, welding, heating andother industrial fields but also used in medical fields because of its high heating efficiencyand mechanization, such as magnetic induction therapy instrument. Magnetic inductiontherapy as a new technique for tumor treatment come up in recent years and considerableprogress have been made.The induction heating power supply based on DSP are studied in this paper. Five partsare included:rectifier circuit, soft chopper circuit, inverter circuit,control and protection.The BUCK circuit are used as a method of power regulating and a new modulation calledsoft chopper for the adjustment of the power of induction heating power supply areperformed. The switching device operates at the state of ZCS and ZVS so the switchingloss of switching device are reduced, therefore, the system is more stale. PSpice simulationsoftware are used for simulation of each part at the same time.Various rectifier circuit arefirstly analyzed in this paper, including the controllable and uncontrolled rectifier ridge,thestructure and positive or negative characteristics of transistors, the selection of rectifierdiode and the calculation and selection of filter capacitor, to use the non controllablethree-phase ridge rectifier circuit; later, several various of chopper circuit are analyzed anda proper kind of structure of the chopper circuit and the main switching device type areselected. Output power of induction heating power supply can e adjusted y soft chopper,the problem of the large switching loss of chopper switch device is solved, and it is verifiedy simulation. Finally, two kinds of topological structure of the resonant circuit in thispaper are taked for example, the advantages and disadvantages of them are analyzed andthe load series resonant circuit is selected. Through calculation of inverter circuit parameter,a proper ridge arm switch device for induction heating power supply is selected.In this paper, a preliminary design scheme of induction heating power supply is done,PSpice simulation software for simulation of rectifier filter circuit is used, the feasibility ofthe scheme is verified y soft chopper circuit, inverter circuit, and the simulation resultswhich has een obtained.