Study And Design On The Medium-Frequency Current Supply Of Induction Heating Equipment

This thesis introduces a kind of current supply of the induction heating equipment and its design scheme. The application of the current supply can make the induction heating equipment frequency changes more flexible. An ideal frequency is chosen to make the induction heating equipment work more efficient and save more energy and time.The major parts of the job in this thesis are the design of the current supply integral structure, the analysis of the current supply operating principle, the design of the system hardware circuit and the software.This main circuit of the current supply adopts AC-DC-AC structure. It contains the rectifier, DC wave filter, inverter, AC filter and insulating transformer.Firstly the 50 Hz AC commercial power is changed into smooth and steady direct current by the rectifier and wave filter. Then the direct current is changed into AC pulse width modulated wave by two single-phase parallel bridge inverters. Finally the alternating current from the inverters passes through the LC filter circuit and the insulating transformer, producing the alternating current required.This power supply uses the MCS-80C196MC as the central control element of control panel and M57959L as that of drive panel. This thesis designs the control panel and drive panel circuits and their peripheral circuits, including the circuits of rectifier and trigger, the button setting, display unit and the detecting part, etc.The thesis gives the main program and every interrupt processing routine, the program flow diagrams of waveform generating, A/D interruption subroutine and current & voltage regulation program in detail, establishes the sine function table, and explains some of the invariables in these programs.