Research And Implementation Of Power Regulation In DC Side For DE Inverter

Induction heating has the features of high efficient, energy-saving, safety, etc. This kind of new technology has been widely adopted both in industrial manufacturing and civil fields.Based on the application of induction heating power supply, a quasi-resonant full-bridge topology with operating as a class E converter has been proposed in this dissertation to improve the frequency of the inverter power. The power regulating method of the inverter is also analyzed. Via comparison, the buck topology is selected which connected in DC side as the power regulation mode. By controlling the DC output current, the input power of the inverter is adjusted. Thus the power of the inverter can be regulated. This control method can achieve power regulation function in class DE full-bridge topology under a wide range of power conditioning. The switch loss in inverter and frequency are improved simultaneously.This thesis contains the analysis of class DE full-bridge topology and basic chopper topology with 3 operating states. According to the design, selection and production process of main components are given in detail. Also, this paper showed the calculation of main controlling parameters and matching of load network. Buck topology has been utilized as the main topology to modulate the power through modifying the duty cycle in a wide range. Considering the advantages of quick dynamic response, each cycle testing, single current loop control mode is designed. The PWM waveform is generated by UC3842 through comparing the sampling current from the inverter and the reference control signal. The output complementary signals are used to control the switch in Buck topology.To verify the feasibility of the design, a prototype is proposed with adjustable dc output current between 50 A to 200 A and dc output power between 5 k W to 80 kW. The experimental results showed that this prototype satisfied the design requirements. Also wide range power regulation and soft switching are realized. Therefore, the design of induction heating power supply in this dissertation has some practical value.