Research On LCLC Resonant Load Of The High Frequency Solid State Induction Heating Power Supply

Firstly, the topology and circuit specification of the LLC resonant topology characteristic of induction heating voltage source inverter is discussed briefly in this paper. To solve the problems that the switch components would work at large phase angle and the switch losses would increase under the low quality factor Q in MOSFET single phase full-bridge high frequency inverter LLC resonant load, this paper presents a new LCLC load matching topology for high-frequency induction heating voltage source inverter. By adding additional capacitor, the phase angle of the switch components and switch losses can be reduced.The topology, output power, output current ratio and voltage ratio of LCLC load resonant circuit are analysis detailedly.Furthermore, matching the load parameters and simulating the theory of the analysis.The simulation experiment shows that the LCLC load resonant circuit not only has the charcateristics of the circuit current transformation of LLC load reaonant circuit, but also can reduce the switch losses and improve the output power, meanwhile strengthen the stability of power supply. Using EP2C5T144C8 FPGA as the main control chip, control pulses are generated, and the dead time could be flexiblely modified.Through sampling of the inverter output voltage and parallel branch resonant capacitance current, the single close loop lock phase control of the system is completed. The current and voltage protection circuits are designed to ensure the safety operation of the power supply. Finally, the prototype experimental results validate the proposed approach feasibility and theoretical analysis'validity.