Research On Large Capacity DC-AC Converter

The technology of large capacity DC-AC converter plays an important role in the area of metal heating process, especially the induction heating power supply technology, which could promote the development of our national economy. This paper took the DC-AC converter as the research object, which based on MOSFET as the switch device. Through adopting the parallel resonance topology structure, a parallel type of high frequency inverter power supply has been designed.This paper introduced the development history of DC-AC converter and the basic knowledge, at the same time made a summary on the development of the power electronic devices and the induction heating. Also, this paper analyzed the principle of the two kinds of topological structure, series resonant inverter and parallel resonant inverter. And theoretical analysis on direct current power has also been done.Through the analysis of the working state, this paper pointed out that capacitive quasi-resonant state is a safe and reliable working condition for the inverter. The system adopted the phase lock loop technique to realize the inverter frequency automatic tracking. This paper designed the MOSFET drive and protective circuit which is suitable for the parallel inverter, also gave the control circuit for the rectifier and chopper main circuit and inverter main circuit, drive circuit for MOSFET as well as protection circuit.