Research of Simultaneous Dual-Frequency Induction Heating Power Supply Based on Single Inverter
|Keywords||induction heating power supply gear hardening frequency tracking simultaneous dual-frequency induction heating|
Based on electromagnetic induction principle, induction heating is heating metallicworkpiece technology by eddy current induction heating effect. Comparing with directheating technology,such as the traditional electric resistance furnace, flame furnace andso on,induction heating has the obvious advantage of uniform heating, high thermalefficiency, fast heating speed, energy conservation and environmental protection, highsafety and reliablity. This advanced technology is widely used in metallurgy, machineryprocessing, national defense and other departments, which has the extremely vitalsignificance in improving energy efficiency, promoting the sustainable development.Simultaneous dual-frequency induction heating has outstanding advantage in complexsurface quenching, such as gear that is the most widely used in modern mechanicalcomponents.Firstly, this paper introduces the application background of induction heatingpower supply and the basic principle of induction heating, and sums up the developmenthistory, current situation and the future of induction heating power supply. According tostructure and working principle of the two kinds of single frequency induction heatingpower supply, characteristics and advantages of dual-frequency induction heating powersupply are comparatively analyzed. Then this paper determines the simultaneousdual-frequency induction heating power supply based on single inverter as the finalsolution. Significance of the topic and the research content and research difficulties arepresented in the first chapter.Secondly, this paper outlines the structure of single inverter simultaneousdual-frequency induction heating power supply, analyses and determines the solution ofthe working principle of rectifier part and inverter part. By simplified calculation thecomplicated resonant circuit parameters， characteristics of the resonant circuit areanalyzed.Thirdly, based on the results of the theoretical analysis, ideal simulation modelwith PSCAD/EMTDC simulation software is established. The circuit topology andparameters are analyzed which verifies the circuit’s correctness. And then, frequencytracking feedback circuit is added, and through monitoring the phase of load’s electric current and voltage, input frequency of signal sources are changed in time, so as toadjust the working frequency of load resonant circuit. The load circuit can respondquickly and stably work on medium frequency and high frequency resonance points.Fourthly, open loop test prototype is made using the existing test equipment in Lab402of Institute of Nuclear and New Energy Technology. Chapter4of this paperillustrates the test methods and results of test components parameters in detail.Resonance circuit components are chosen according to the circuit requirements and thedriving signal circuit board is constructed. Then test process is reviewed, and test resultsare analyzed, which coincides with the theory and simulation results.Finally, the theoretical analysis, simulation and experimental validation of thesimultaneous dual-frequency induction heating power supply based on single inverter issummarized. Improvements in theoretical design and prototype are given at the end ofpaper.