Small Power Level Induction Heating Inverter Power Supply Based On FPGA

As the emerging power of the modern heating technology, induction heatingtechnology, especially induction heating power supply, has played an important role inindustrial production and real life in recent years. Traditional single power adjustmentmethod can’t meet the demand of society, namely efficiency, energy saving and digitalrequirements. So power control technology towards high efficiency andintellectualization is needed. And output power control technology of small powerlevel induction heating is focused in this paper.Firstly, characteristics and overview of induction heating inverter power aredescribed in this paper. as well as its overall structure. Half-bridge inverter is suitablefor small power level power due to its simple structure, low electromagnetic radiationand robustness.Then the improved half-bridge inverter topology for multi-loads basedon conventional half-bridge inverter is proposed. Several control ways of powersupply are described in detail. Asymmetrical PWM is chosen in this paper.Secondly, operation modes and typical waveforms of proposed topology circuitare analyzed. And Matlab/simulink simulation tool is applied for modeling andsimulation experiment and comparative analysis based on simulation results verifyrationality of operational mode analysis. ZVS is achieved to decrease losses.And theefficiency of inverter requires further verification. So snubber capacitance andswitching dead time are identified in charter4, and power devices losses (conductionlosses and turn-off losses) in an operation cycle are analyzed and calculated further.Finally, digital design of the inverter power is shown in the paper. Loadparameters change as the heating process proceeds, and resonant frequency willchange, so DPLL design is needed for tracking to match switching frequency withload resonant frequency. Hence AlteraFPGA platform is applied to adjust outputpower, in which Verilog HDL is used to realize regulation of switching device drivingpulse duty cycle and switching frequency, and its main advantage is strong flexibility,with modular design and short reconstructed design cycle and so on.