Design of an LCC resonant converter for furnace power supply during electron bean melting

High-power converter applications are usually realized using the hard-switching technology under a low-switching frequency condition; moreover, the isolation transformer size must be larger. To reduce transformer size, the switching frequency must be increased; however, this increase directly results in the increase of switching loss. This paper proposes a high-voltage(HV) and high-power supply by using a thyristors-controlled rectifier and LCC series parallel resonant converter (LCC-SPRC). The introduced DC-DC converters are connected in parallel at the input side and in series at the output side, and soft-switching technology is applied to reduce the switching loss by using the frequency control mode. In addition, an equivalent mathematical model of LCC-SPRC with discontinuous current mode1 (DCM1) was analyzed in detail. For obtaining accurate parameters of LCC-SPRC, the Matlab/Simulink software was employed to calculate the system parameters, and provide the system with dynamic simulating curves. The simulation and experimental results verify that the LCC-SPRC design scheme of for supplying furnace power during the electron beam melting (EBM) is feasible in applications. © 2017 The Institute of Electrical Engineers of Japan.